When someone has grid connected solar panels, they are usually trying to maximize total output, as they can sell all power straight to their power utility through the wires connected to their home. With off-grid systems, there is by definition no connection to the grid, so when you generate your own electricity, you are in a ‘use it or lose it’ kind of situation. As we’ve written elsewhere, solar electricity generation in an off-grid home isn’t about producing the maximum possible amount of power, it is about trying to make sure that you don’t run out. Further, there is great variation in the amount of sunlight available over the course of a year. Here in Ottawa there is four to five times as much energy available from sunlight during the long days of June than in December. On top of that, the cold and dark parts of winter require a lot more electricity to power things like lights and heating systems. Off-grid solar systems need to be designed to cover these winter needs, and so overproduce during all of the warmer and sunnier parts of the year. Putting all of this together, it means that most off-grid homes waste a lot of the electricity that the panels produce.
Up until December of 2018 this was the exact situation for the Manitou Bay house, where we were only using about 20% of the total power that the panels could have made available. During much of the year, our battery bank was full or nearly so, and all of that extra electricity was left unused. Knowing about this waste nagged at us, that we had all of this electricity with no place for it to go. We knew it was possible to do better and so made a plan to fix things, but due to it being somewhat lower priority as well as some unforeseen delays, it ended up taking almost three years to put that plan into action.
We have now installed some new hardware that allows us to utilize much of that wasted power. In principle, all we have done is add an automatic system that switches on some electrical devices anytime there is extra electricity available – on bright and sunny days. These extra electrical loads are called ‘opportunity’ or ‘dump’ loads, and need to be those things that are useful to us even though they only turn on during sunny days. This means that it can’t be things that we absolutely require, or those that we want available at a moment’s notice. We currently have one major need that fits this description, which is supplemental heating. Up until now much of our active heating has been accomplished with propane. The new system will do space heating through all the colder months, and make hot water for showers and the like during all of the summer months. We expect that this could cut our propane use at the house by a third (see below). In the next couple of years we will have one more use of intermittent power, to recharge an electric car, when we replace one of our current gasoline powered ones around 2021 or so.
This principle, of using electricity when it is cheaper or more easily available, is one of the main ideas that will underlie the ‘smart grids’ of the future. Right now most users simply turn on any power needs that they want whenever they want them, but in the future we will be able to set our heating, cooling, charging, and other devices to automatically turn on when power is cheaply available, and turn off when it gets more expensive. This will save everyone money, and will allow more renewable energy into the grid and give greater flexibility to utilities. What we have done with our upgrade is to make our off-grid home something of a ‘smart’ microgrid.
How the relay works (the rest of this post will be a bit more technical). In our situation, we are using the voltage of our battery bank to regulate our intermittent loads. When the batteries are full and the voltage is high the switch turns on, and when the battery voltage falls to about 80% the switch turns off, as we need to keep a healthy amount of power in reserve for all of the normal electricity needs. Our charge controller (system details here) has the components and software built in that can control a switch based on voltage. However, this switch can only control a low power direct current (DC) circuit, not the higher energy alternating current (AC) electricity that is typically used around a home. So this is why we had to add new hardware in December, installing a relay so that the DC circuit could control AC circuits that go out to the heating and plug loads where we have the intermittent power consumers.
How much electricity will we effectively gain by adding the relay? Before adding this relay, the house consumed a bit less than 5 kWh per day of electricity year-round, or about 1500 kWh per year. Based on a power production estimate that we had done when our solar system was installed, which is now doubled since we doubled the number of panels, our solar system could produce up to about 7500 kWh of electricity per year. Now that we have the relay, we will be able to capture much of that excess. From November to April we will put every extra kWh into space heating with a 1500 watt plug-in heater. In December this is only anticipated to be about 2 kWh per day, while in April there should be an extra 20 kWh per day. From May to October, the extra electricity will be routed to a standard electric hot water heater. We estimate that with the number of showers that we take that we will consume around 10 kWh per day of electricity through the water heater, which still will leave a fair amount wasted during the sunniest months of May to August. Add all this extra power up, and we will use around 3600 kWh of additional electricity. We should now be using about 70% of the total output of our system instead of the 20% that we managed before the relay was installed. See the table below for specifics.
Daily extra kWh used
We’ll wrap up by going over the greenhouse gas emission and financial reasoning behind this project. Before adding this relay the home was using about 400 gallons per year of propane. Adding 3600 kWh of electric heat should reduce the propane consumption by around 140 gallons. By avoiding burning all of that propane, we will reduce our CO2 emissions by a full metric ton each year (this is a part of our 5 year plan to reduce our emissions by half). The cost savings for that propane not purchased will be around $350 per year as long as the system keeps running. The relay work cost a bit less than $1000 and the electric hot water tank cost about $500, and so the work will pay for itself in under 5 years. Finally, I ought to mention that even with this increased efficiency, solar electricity off the grid isn’t cheap. Considering all the panels, electronics, batteries and labor, and the fact that most of these components only last for 10 to 20 years, even with the relay our solar electricity still costs around $.50 per kWh. This compares to power from the local utility, HydroQuebec, that comes in at around $.10 per kWh. With the secluded location of the home off-grid was the only sensible choice, but the costs do make one appreciate the value one gets by tying right into the power grid.
Special thanks to Tom Hewitt at NetZero Construction for his assistance with the solar and DC circuit work, and Jean-François at Lamarche Electric for all of his work installing the relay and AC circuits.
I always wanted to own property in the countryside. I loved the hiking, fishing, canoeing, and other related outdoor pursuits. But there is something different when one is the owner, the land manager, and if done right, the steward. When we relocated to Ottawa, the Canadian capital, finding a place outside the city to call our own was something that was at the top of the list. Within a year of our arrival, we found our perfect spot – nearly one hundred and fifty acres of field, forest, and wetland, spread across rolling hills and nestled alongside the Gatineau River. It felt quite wild to me at the time, but they called it a farm. It was little like the flat open farmland that I was used to seeing during my childhood in Minnesota and Wisconsin, where fields run together and sometimes the only trees are those just adjacent to farmsteads and along fencelines. On this property, there was no barn or silo, but rather a few modest hilly hayfields, and a forest where trees were cut occasionally for lumber or firewood. When my wife and I had begun looking for our countryside escape, we thought about what we wanted mostly in terms of lifestyle and recreation. But it is a farm, and we had become farmers.
From the time we purchased the property, my mind was overflowing with the possibilities of what we could do there. Of course, much of my attention was on all of the recreation that our family would be doing, a broad swath of sports, including snowshoeing and cross country skiing all winter, hiking and fishing the rest of the year, a bit of deer and grouse hunting thrown in during the fall. But it was never just about recreation, it was also about stewardship and sustainability, taking proper care of a space, using it in the present, but preserving it for the future. As much as possible, we wanted to live lightly on our new property, preserving the full range of flora and fauna that are found there. The main reason for choosing this particular property was the natural aesthetic of the place, which we wished to preserve. Since I was a young child, I had dreamed of living out in the wilderness, of living off the land. But as I grew to adulthood, I realized that the sort of rugged independence where I would build a house by hand and grow all my own food was not the dream that I was pursuing. I have no desire to be fully separated from the rest of the world; people are social beings, and productive societies always exist by working together, each specializing to use his or her own talents and predilections. We need those goods and services that others produce, but I also knew that we needed to make sure that we, as a world, live in a way that is sustainable so that our children and their children will be able to continue to prosper as we do today.
Real sustainability isn’t only conservation, and leaving all natural places free of human influence. While true nature refuges are critically important, people also need to produce many goods from the land to support themselves. I felt that part of my responsibility was to continue to keep this land productive, to help provide for human needs as well as to be a wild and natural place. A question kept coming back to me: Was our farm, in this rocky and hilly Canadian forest, even capable of being productive enough to support my family and our needs? As I began to work through all of the possibilities, I considered how it was possible to compare them; Should we grow trees or corn? One way to answer these questions was to simply ask which one would yield the highest dollar returns. This is certainly the typical way that farmers make their land-use decisions. While we wished to make a few bucks, concerns of sustainability stayed at the fore, and our main incomes will always be off the farm. I then had an epiphany about our land use planning. It wasn’t the most original, but it is one that is key to land management, and I’ll share it with you: All farming and most sustainable land use is the farming of sunlight, capturing some of those rays and using the energy contained in them. One takes sunlight, and converts it into maple trees or wheat, chickens or deer. So my realization meant that the question that I was asking about providing for my family was really a question about energy. I started to come around to thinking about sustainable land use more broadly as being about energy; how much energy could we capture and use? What kinds of byproducts and waste would be created? Was a farm like ours capable of producing enough to support the energy-intensive modern lifestyle of my family? How much energy does it really take to support a family anyway?
At the same time as we were purchasing our property, we were also busy with starting to design a house that we would build on a hilltop overlooking the river. For years I had also been interested in architecture, particularly green building practices and energy efficiency, and so we decided to design a place that would be incredibly energy efficient from the ground up. We received an extra push for efficiency from the fact that our building site was so far from the nearest power lines that it would have cost a small fortune to run power to our new home. Solar photovoltaics were going to be the only reasonable way to provide electricity. Going with off-grid solar almost automatically puts one in an energy conservation mind-set, because for every extra light or computer you want to power, you need to pony up more cash upfront to install more panels and batteries. Energy of all kinds was going to be at a premium at this location, so we made decisions to reduce use and keep all appliances and mechanical systems efficient. To reduce heating needs, we took inspiration from several different green design movements to incorporate passive solar design and superinsulation to our home. All in all, we reduced by approximately 70% the amount of energy that we will need to use in this home compared to standard construction. In working with an architect and tradesmen of all kinds, I learned the ins and outs of energy flows around and through a home, and in many ways they really didn’t seem so different from the energy flows involved with land use.
While working on both land use planning and home design, I was consulting innumerable sources, on forestry, farming, energy, architecture, and more. As written, each of these sources was aimed primarily at specialists, the professionals who work in these fields. What wasn’t there, and that I yearned for, were some of the threads that tied all of these concepts and practices together. How did each of these fields relate to the human level, an individual, a family? Again, I could see that in each, a common theme of energy use was central to each of these endeavors. Sustainability and renewable energy are tightly intertwined, and I was learning enormous amounts about how these systems worked, and could see a place for sharing this knowledge with others. Much of this website is built on this inspiration and these insights, putting together the ideas and resources that I was searching for on our own path to a more sustainable lifestyle.
Shifting to a truly sustainable society is going to be a long process and will require many adjustments both large and small to the way that people live. We here at Sunshine Saved want to do what we can to fast-track this change, and as part of that we have made plans to reduce the carbon emissions of our family’s lifestyle by half within the next five years. Hopefully this will provide some inspiration for others to find their own ways to reduce their footprints. This article builds on the accounting that we did for my family’s 2017 resource consumption, figuring out what we can and will do in the near term to increase the sustainability of my family’s lifestyle, projecting out to 2022. We’ve taken some important steps already but have much more to do.
Everyone is in different circumstances of jobs, income, locale, lifestyle, and family, and that will be reflected in which things they could do to improve sustainability. For us, and for a majority of North Americans, one of the highest priorities is to reduce usage of fossil fuels. And in fact this is the main work that we will do with our 5 year plan, to directly reduce our usage of gasoline, natural gas, and propane.
Overview of our current emissions
The above chart shows our 2017 carbon emissions on the left, and the target for our 2022 emissions on the right. Carbon emissions aren’t the only way that we look at our impacts, but they are very important and easier to measure and quantify than many other things. As you can see for our 2017, the biggest contributors were related to housing, our personal vehicle use, food, and consumer goods. We are targeting each of these in turn as you will see in our action plan below. In 2017 we had emissions of 28 tons of CO2e for a family of four, and the plan for 2022 is to be down to 16 tons of CO2e for our slightly expanded family of five. This would bring us down from 6.9 tons to 3.2 tons per person, more than a 50% reduction.
As you will see below, we are putting our efforts into those things with the most ‘bang for the buck’ both in terms of dollars but also effort. Making changes isn’t easy, so we are trying to really focus on changes that provide big impact with as little effort as possible, as well as those things that we will enjoy or otherwise be able to maintain. For instance, switching to an electric car (or simply a more fuel efficient gasoline powered car) is a single decision that will reap benefits for the lifetime of the vehicle without any further effort. But for something like cutting out plastic packaging, this requires continuous and daily changes in behavior such as only shopping at specialty and bulk stores, losing a lot of convenience and taking more time and constant effort. This isn’t to say that reducing plastic use isn’t a good idea, it is just that other things should probably be prioritized over it.
Finally there is the direct monetary cost. Very few people are going to freely choose a more sustainable pathway that is twice the cost of ‘business as usual’, but there are many ways to go green while also protecting the pocket book. Reducing consumption usually directly reduces costs. Some of the bigger steps may take more cash and planning up front, but they are followed by big savings in the costs of fuel, maintenance and replacement later on. So while we won’t go through all of the finances of our decisions directly in this article, the combination of all of the moves outlined below shouldn’t cost us any more than a business as usual scenario .
Housing in the city of Ottawa
In 2017 we lived in a rented semidetached home (duplex) as outlined in a prior article. We knew that we wished at some point to purchase a home in the city, and sustainability concerns certainly figured prominently in our decision making process. We were able to find the right place and moved into it in mid-2018. This home is another semidetached dwelling, and our half of the building contains a main unit on the upper levels along with an apartment to rent out on the basement level. We are intending to stay in this home until our children are adults, and with a newborn in the summer of 2018 that means we have a good 20 year planning window. This longer timescale makes some sustainability changes more viable; for instance, if we put in higher efficiency appliances or more insulation it is us who will directly reap the long term energy savings.
Reduction in driving – As they say, “location, location, location”. As so many do, one of the main criteria for our new home is how well located it is from the places that we regularly go. In our case, this is school for the kids, work, errands to stores, and the farm. We were able to narrow down to a couple of neighborhoods that would reduce the distance to all of these places, and our new home is now in walking distance from the kids’ schools and a new light rail station that one of us takes to the office. It is also 10 minutes closer to the farm. Altogether, this new location should reduce our driving (already lower than average) by one third or more.
Heating– Our new home came with a natural gas forced air furnace. Around Ottawa this is the default choice for the majority of residential homes, and the same as our prior rental. This is the cheapest option in a typical home in our area and produces a medium level of carbon emissions as compared to other options. This is a new and high efficiency furnace, and we decided that augmenting the existing furnace with auxiliary forms of heating would be the best way to reduce the amount of fossil fuels that we use.
The biggest heating problem in this house on moving in was for the basement apartment. The basement is insufficiently insulated, and so is always significantly colder than the main unit (We would like to re-insulate the space, but this won’t make it into the five year plan, but should for the 20 year plan). Further, the house’s gas furnace isn’t ‘zoned’, in that it either provides heat to the whole building or none of it. Put together, this means that the basement needs an additional heat source. We considered electric baseboards, but instead have settled on a much more efficient option, a Mitsubishi cold climate air to air heat pump, also known as a mini-split (we’ve discussed heat pumps before here), installed in September of 2018. This heat pump, though a bit more expensive up-front, will use only a quarter as much electricity as electric radiant baseboards, and will have a very low carbon footprint due to the clean energy grid that Ontario has in place. This heat pump will give the apartment renter full control over the heat in the apartment. It will also provide for some of the baseload heat for the upstairs as much of this heat will rise up from the basement to the upper levels. Only time will tell for the exact numbers, but quick calculations suggest that the heat pump may reduce natural gas usage from the furnace by about a third.
The second way that we will reduce our natural gas use is to do a significant amount of our home heating with wood. This isn’t a solution for everyone, but with working from a home office, enjoying tending a fire, and having a nearly unlimited supply of sustainably cut local firewood, it makes a lot of sense for us. The house currently has a 35 year old fireplace on the main level. Most older fireplaces actually provide little relief on heating bills; they heat up the room that they are in but they also suck vast amounts of warm air from the inside of a home and send them up the chimney. They also burn inefficiently and produce a lot of unhealthy air pollution. However, newer high efficiency wood stoves are another story completely. They tightly control the fire and airflow, allowing them to burn very cleanly as well as do an excellent job of heating a home. In 2019 or 2020, we will swap out the current fireplace for a high efficiency woodstove. If things go as planned, a fire will burn on half the days through the winter, which should further reduce the remaining heating needs of the house by half.
The new home is a bit bigger than our 2017 rental, and so we estimate that it will use 50% more natural gas than our 2017 numbers if we make no changes to our behavior. Heat is now provided for 6 people.
The combination of a basement heat pump and a regularly used wood stove will reduce natural gas consumption by 2/3
Combined, this means that we will use half as much natural gas as we did in 2017, using 740 cubic meters of natural gas which will release 2 tons of carbon dioxide in 2022
This means .35 tons of CO2 per person per year, down from 1 ton per person in 2017, a 65% reduction in natural gas consumption
The home at the farm is off the grid, with electricity produced by solar panels and heating done mostly with propane. With solar panels that are connected to the grid it is easy to sell any extra electricity on to other users, but this isn’t possible off-grid; either you use the power or it goes to waste. So in the first few years this home had no way of using any extra power and it was wasted, but we have figured out a way to change that. We are going to add a smart switch that will turn the power on in some circuits when the batteries are full and then turn off the power when the batteries drain down to about half full. The cost to implement these changes should be paid off in 2 to 4 years in reduced propane costs.
This extra electricity can then be used in ways that allow us to reduce other energy use, in particular the propane heating. In the winter any extra electricity can be directed into a resistance heater which reduces the amount of heating that we have to do with propane. From spring through fall, some of the electricity can be used in an electric hot water heater, bypassing the need to use the current propane water heater. Finally, once we have a plug-in electric vehicle (see below), we can use any additional ‘extra’ electricity to charge that vehicle.
We hope that by using all of this currently wasted electricity that we can cut our propane usage in half. This would bring us down to 200 gallons per year, and reduce CO2 emissions from 3 tons to 1.5 tons per year.
Replacing our vehicles with electric ones
We would be happy going down to one car, but that may not happen in the 5 year plan. This depends in part on what happens with car services (car sharing, Uber, Lyft, the coming of autonomous cars, etc.). Between managing a family with three small children and also regularly traveling to and working out at the farm, we wouldn’t want to give up our vehicles until other options could replace the conveniences of having our own.
What we can do instead is to plan to only buy electric cars from here on out. We will make that switch as soon as electric vehicles come available that can meet four key needs: a range of about 200 miles, big enough for our family’s needs, all wheel drive, and relatively reasonably priced. These cars are certainly on the near-term horizon. There are already several electric vehicles available that meet three of these four criteria, but not all of them. Dozens of new models of electric vehicles from most of the major manufacturers are due to be released by 2021. We eagerly await those vehicles that could serve our needs.
Electric cars are already better for the climate in most jurisdictions, but they are a particularly good choice in Ontario and Quebec. This is because the electrical grid in these provinces produces very little carbon pollution, being mostly powered by hydroelectric and nuclear power plants. This means that almost all of the carbon pollution from owning these cars comes from their manufacturing rather than driving them. An electric car does have a higher manufacturing footprint as a comparable gas car mostly because of the resource intense batteries, but cutting out the gasoline itself still leads to enormous overall reductions in pollution. As the vehicles that we will purchase next aren’t even available yet it is hard to calculate any precise estimates, but my best guess is about a 75% reduction in our vehicles’ total carbon footprint, a very large savings.
Growing our own food
We have a lot of plans for our in terms of forest management and some farming endeavors which are discussed over at our farm page, but much of that work isn’t relevant to anyone who doesn’t manage a larger property. The part that is more applicable to this discussion is food, namely that we are going to grow much more of our own food. Our ambitious goal is to get to half of our family’s food produced directly on the farm. As of the writing of this piece in the fall of 2018, this work is still in its infancy. The orchard was planted just this spring, and the preparatory work for a much larger garden is currently underway. Livestock should become part of the mix by 2022, but may be limited to broiler chickens which we would acquire as chicks in the spring and harvest in the fall.
For all of our farming efforts we are going to be applying the principles of regenerative agriculture, trying to maintain the health of the land and soil as we grow our food. We will use little or no pesticides and intend to use natural fertilization rather than chemical fertilizers. We will further avoid leaving bare soil, which will help to hold soil carbon and reduce erosion. Needless to say, this will reduce the ecological footprint, including the CO2 emissions, associated with our food. If we are able to scale our production to the level of half our family’s food production, it should also reduce the emissions associated with our food by a similar amount.
If you’ve made it all the way through this piece, then you may be interested in seeing numbers used to make our 2022 estimates. They can be found in the table above and are being shown next to our 2017 numbers. It won’t quite be a 50% reduction in absolute terms, but will be over 50% when one considers the per person emissions. Now we just need to carry through with the rest of the plan.
***If you are not a numbers person I apologize in advance, and suggest that you don’t worry too much about the precise details and instead just try to take away the bigger picture.***
If a person wants to live more sustainably, one very important step is to take stock of your current circumstances. Putting real numbers to one’s use of energy and resources allows you to see which things really matter, where the problems are, and gives hints to the solutions. This post is an accounting of the energy consumption and associated emissions of greenhouse gases of the lifestyle lived by my family during the entire year of 2017. We have already taken a fair number of steps to minimize the impact of our lifestyle, but we still have much work left to do if we are to do our fair share to keep the world livable.
Something like 80% of the energy and resources that we each consume is connected to household goods and services, with the rest being our share of the services provided by the government. The majority of this resource use is under our direct control in our homes, our cars, our products, and our food, while the rest is only indirect; we don’t control that much about the hospitals, businesses, or restaurants that we frequent. For the purposes of figuring out what the average person can do about sustainability, it makes sense to separate out those things that are under our direct control from those that are not. It isn’t that we can’t have an impact on government or industry, it is simply that the advocacy related to voting, lobbying, or boycotting organizations to change their policies and behavior is very different from the decisions we make about heating our homes and which cars to buy.
For the purposes of accounting for my own household’s energy use, I’ll stick to those things that are under our direct control, namely housing, consumer goods, personal transportation, and food, and not address those that we don’t have a lot of control over, government and services including things like hospitals and schools.
We begin this account with a table including our major sources of energy consumption in 2017, seen below. This includes my best approximation of everything that we did and its impacts. This table breaks down where and how we used energy as well as what form it took. I then include the figure that matters most for climate change, emissions of tons of carbon dioxide equivalent (CO2e). Most of these emissions are actually carbon dioxide, but also include things like nitrous oxide and methane. We’ll examine each of these energy uses in turn below (these estimates are drawn from various sources, anchored by analyses from Jones and Kammen, 2011). As you can see in the table below, our direct household activities had effective emissions of 28 tons of CO2 in 2017.
Duplex in Ottawa
I would actually much prefer to live full-time out at our farm in the hills north of Ottawa, but this would require a daily commute of an hour each way into the city for work, and schools other services are very limited out in that area. On top of that, my wife isn’t ready to be a full-time country woman. So instead, we have been renting a 3 bedroom duplex unit in the city, and then spending two or three days a week out at the farm.
Our biggest energy consumption in the duplex is natural gas, used in a forced air gas furnace and a tankless hot water heater. Natural gas is, unsurprisingly, delivered in gaseous form, so it is measured by volume; we used 1480 cubic meters of the stuff in 2017 (52,300 cubic feet if you’re in the US). Natural gas heating is currently cheaper than almost any other source of heat in much of North America including here in Ottawa. From a sustainability standpoint, it is an imperfect choice because it is a fossil fuel, but it isn’t quite as bad as other fossil fuels for emissions. Society must wean itself off of natural gas in the future, but it is a tolerable choice for the time being. At the moment, the best local choice for more sustainable residential heating may be heat pumps backed up by natural gas on the coldest days, which may be the path we take once we own a home in Ottawa.
The lion’s share of this gas is for space heating in Ottawa’s relatively cold climate. Ottawa has similar heating needs to some of the coldest areas of the continental US, very similar to Minneapolis or the colder parts of New England. The building itself is nearly 100 years old, but has been renovated and has relatively new insulation and windows. It probably has insulation and air-tightness levels of a typical 10 to 20 year old home. One big advantage is that as a duplex it shares one entire wall with an adjacent unit, which reduces heat loss for the whole building by around 25%. We keep the thermostat set a bit low in winter, around 19 Celsius ( 67 Fahrenheit), and have a smart thermostat that turns down the heat overnight. Combined, these measures probably shave another 5 to 10% off the heating loads as compared to business as usual.
We have a tankless hot water tank in this house. The benefit of tankless hot water is that one only heats up water when it is called for, and doesn’t have ‘standing losses’ when hot water in a big water tank cools between use. Having lower flow shower heads and keeping showers to a reasonable length also moderate hot water use.
We used 6635 kWh of electricity from Hydro Ottawa in 2017 in our duplex. Ontario (and neighboring Quebec) have very low CO2 emissions for their electricity since very little of their power is generated through fossil fuels. Across the river in Quebec power is almost exclusively generated by hydroelectric dams, and here on the Ontario side, in addition to significant hydropower, over half of Ontario’s electricity is generated at nuclear power plants. Nuclear power has concerns of its own, but if one takes climate change seriously it is something that should probably be included in the mix as nuclear power produces almost no greenhouse gas emissions. Our personal electricity use is fairly typical, with most of the power accounted for by the furnace fans, dehumidifier, dish and clothes washer, refrigerator, and household electronics. Our landlord did a good job of choosing high efficiency appliances.
The final energy use of our duplex is embodied energy. As discussed elsewhere on Sunshine Saved, the basic idea is that it takes a lot of energy and resources to build things and those things eventually wear out, so one can calculate how much energy is being ‘used up’ each year in deterioration and aging. There are an awful lot of parts making up a house, concrete, wood, electrical and plumbing, lots of of workers and goods transported to the site, and more. The saving grace is that houses last a long time, perhaps one hundred years on average. One can then add up all the energy that goes into building a home and divide that by the number of years it will last. Doing this, we estimate that the aging of our home accounts for the equivalent of 1 ton of CO2 emissions per year.
The house at The Farm at Manitou Bay
Our off-grid home is discussed in great detail here, and the design and building process for this house launched our work here at Sunshine Saved. This house was designed from the ground up to be efficient, both for reasons of sustainability as well as to make it much easier to take a four season home in our northern location off the grid.
Though this house has solar panels, the energetic heavy lifting is being done by propane. The biggest energy user of any home in our climate is heating, and this is the exact same time of year when days are the shortest and cloudiest. It is, at least for the time being, enormously more cost effective to have the majority of heating come from sources other than our solar panels.
Propane is used for the primary heating, domestic hot water, kitchen stove, and a backup electricity generator. In 2017, we burned 400 gallons of propane, which released 2.9 tons of CO2 in emissions. The biggest part of this was space heating. The Manitou house uses about half as much energy for heating as the duplex due to high insulation and airtightness, even though it is a slightly bigger place with much more surface area exposed to the elements.
Solar panels provide for all of the electricity loads. Sunlight as a ‘fuel’ has no emissions, but there is a quite high embodied energy for all of the solar equipment, the panels, electronics, and batteries. All of this gear requires energy to build and it has only a finite lifespan, 10 years for batteries, perhaps 15 for the electronics, and 30 for the panels themselves. I estimate that in 2017 we used 1200 kWh and had an emissions impact of .3 tons CO2e.
In the winter, we heat with our wood stove whenever we are there to tend to it. There is an ongoing debate as to whether burning wood should count as carbon neutral, and my take is that it really depends on scale. Clearcutting forests and shipping them off to be burned for electricity is clearly not carbon neutral. However, the small-scale harvest of trees that would otherwise rot on the forest floor is quite sustainable. I estimate that we have effectively zero emissions as we are selectively cutting trees within a few hundred yards of the house, those trees that are dead, dying or of otherwise low quality. CO2 is absorbed as they grow, CO2 is released when burned in our high efficiency stove. The only other inputs are less than a gallon of gasoline for my chainsaw to do the cutting for a winter’s worth of wood. The amount of wood we burn gives us about 1/4 of the home’s winter heat and produces only a few pounds of excess CO2 emissions from the gasoline.
This house is relatively similar in total size to the duplex that we rent in the city, and so we use the same estimate of its embodied energy, at 1 ton of CO2 per year. With the quality that we tried to aim for with the build, I would hope that this building will last much more than one hundred years, but only time will tell.
Car and truck
At the moment we have two vehicles, a Subaru Outback and a Ford F150. For a family trying to be as sustainable as possible, I admit that this seems a bit odd, to have two vehicles and one of them very large. We would like to reduce to one vehicle, but that has not yet become practical with the needs of a family of five, with work, errands, and a farm property to manage. All wheel drive is a necessity to access the farm during parts of the year, and is much better during the long snowy season in the city of Ottawa also. Managing a forested farm is also made much easier by the capabilities of a pickup. We keep the mileage and therefore gas consumption low, which does help some to reduce the impact of having two vehicles.
In 2017, we put about 6200 miles on the Subaru and burned 220 gallons of gasoline, and had 3400 miles on the pickup truck for an additional 200 gallons of gas. This released 4.9 tons of CO2 into the air.
Finally, there is the embodied energy in our vehicles, from all of the mining, refining, production, and assembly needed to put the cars together in the first place. One can tally up the total amount of energy, and divide it by the lifetime of the car, giving an annual emissions for having that vehicle. Our pickup is a bigger vehicle and so required more materials, and the two combined lead to an annualized production of around 1.4 tons of CO2.
The energy use of air travel is something we discussed briefly in another article comparing modes of transportation, but the takeaway is that traveling by commercial airplane is roughly as energy efficient per mile as driving a car, while air travel really racks up fuel use and emissions due to the large distances traveled. In 2017, my family of four took one trip by plane to visit family, with about 1900 miles in the round-trip flight. Our share of the jet fuel for these flights released 2 tons of CO2.
My family tries to eat well and maintain a relatively balanced and nutritious diet. With very young kids it is seldom that we eat out, but we do a lot of home cooking. Most of our calories come from the grocery store, and from conventional farming before that. We do eat food out of the garden, from local farmers, and a bit more that is hunted and fished, but these make up a very small amount of the total. So for the most part, the sorts of figures discussed on our main page on food and diet apply to my own family as well. We have already adopted the two main recommendations that are outlined there, of cutting food waste almost to zero, and reducing beef and lamb consumption down to only a few times per year. Accounting for all of the farm and commercial equipment needed to plant, harvest, process and deliver our food to us, I estimate that our food consumption accounts for 4 tons of CO2 production per year.
Other consumer goods
On top of the big items of homes and cars, we have all the other trappings of modern life, including appliances, furniture, electronics, clothing, and more. And all of this stuff has a limited lifespan, whether it be measured in days or decades. This is a lot of things to try to account for, so for the sake of simplicity I will simply assume that we buy the same amount of stuff as the average American household (see here for more data). It would be interesting to go through item by item, and that is something that we may discuss at a later date. Using average American household figures, all of the goods that we purchase per year produce emissions of about 6 tons of CO2.
Comparison to average household.
Using the average household data, we can then compare where we were for 2017 with the average American household of 2010. The table shows that our household produced about 28 tons of CO2 compared with the average US household of 42 tons. We are doing better than the average family by about a third. The key differences that allowed my family to have lower than average emissions include:
Much lower mileage on our cars led to much lower gasoline use.
Our homes are well insulated and have efficient appliances and use less natural gas and electricity.
The grid electricity in Ontario has much lower emissions than most of the United States, so the impact of our electricity use is much lower.
We eat very little beef and waste little food.
My family’s 2017 consumption was far from sustainable. We are a bit better than the average North American level, but we have plans to do much more. We have put together a five year plan for our family where we aim to reduce by half our CO2 emissions from our 2017 levels. We’re even developing a more speculative 20 year plan that would bring our family’s consumption down to truly long-term sustainable levels. This longer term plan is less certain because it depends on larger forces of technology development, future government regulation, corporate action, and more. There are actions that we can take as individuals, but that alone will not be enough.
Hopefully this sort of detailed accounting will give some better context for the big numbers that are always being thrown around in discussions of climate change and climate policy. It all comes back to the decisions that each of us make every day – the things we buy, the places we go, how we choose to live. People need to understand how the pieces fit together and what is at stake so that they can act personally and to help change society at large.
From the very beginning of our house building project, I had a lot of ideas about what I wanted to accomplish with the architectural style as well as the interior layout and design. While I think that I would have ended up with mostly good choices by working it out by myself, the assistance of our architect Anthony Mach was invaluable. Even though I had a much clearer notion than many people do going into the early phases, I still often needed that access to an expert opinion about what is doable and how to make all of the parts fit together. And don’t even get me started on the process of turning the rough sketches into final blueprints, I don’t have anywhere near the knowledge to be able to put together those technical details.
For any of you who are considering building a custom home, I would recommend that you start by doing what we did, and make a list of things that you require, those that you would like, and those that you just don’t want to do. Also take the time to look at lots of pictures, as it always helped us to figure out if something would work by finding a good example. My digital scrapbook of inspiration eventually made it to several hundred pictures. And be prepared to revise that list in the face of budget, practicalities, or even your own changing understanding. Our starting list as of the time that we first met with Anthony was the following:
3 bedroom, 2 bath house
Nice screen porch facing the river
Upside-down design, with living spaces on the upper level, and the bedrooms on the lower level
Passive solar orientation (discussed here and here) with plenty of big windows
As compact as possible given what we are trying to fit in, both for energy efficiency as well as to contain costs
Timber framed, or otherwise using lots of natural wood
Contemporary design with a single pitched shed style roof
Resilient design, using well-chosen design details and high quality components, so that house will age well over decades
Big stone fireplace with a high efficiency stove insert
We already had a fairly well-developed plan by the time we went to Anthony, so I feel pretty good that out of this initial list, the only item that was dropped was the large stone fireplace. It turns out that doing these the old fashioned way with larger real stones is both very energy inefficient as well as incredibly expensive. It turns out that the vast majority of the ‘stonework’ that one sees on both the interior and exterior of today’s buildings is actually painted concrete. It is relatively thin pieces of veneer that can be added to almost any wall, and the process now yields fairly realistic looking stone. With this entire project I’ve wanted things to feel as authentic as possible, and fake stone just wasn’t something that appealed to me. As the plans developed further, we realized that the simple clean lines of a wood stove and interior stove pipe were just as good of an aesthetic fit while being much better in terms of cost and energy efficiency.
Open concept living
We, along with a lot of others buying and building houses today, wanted an open concept design, with a single great room containing the kitchen, dining, and living spaces. I have heard and read quite a number of things about the growing popularity of the open concept, and it seems that there are two major drivers. The first is a greater desire for families to spend time together. With parents working more hours, kids doing more activities, families want to spend the few hours where everyone is at home together. The other trend is for increasingly casual living arrangements. People no longer want to hide away the mess of the kitchen and to eat in a formal dining room. This fits just about right with our own decision about building this way; this was always intended to be a place for the family to be together. Opening up the living and cooking spaces to each other solve all of these issues, putting everyone all in one space. We ended up with a room of 18’x38′ (680 ft 2), which has been fantastic for family time and groups up to about 15 people. We often are cooking and doing cleanup at the same time as we entertain or keep an eye on our young children.
A screen porch was another thing that was at the very top of our list of desired features. In our climate it may only be porch weather for four months of the year, but during that time it is the best place in the house. It turns out that screen porches aren’t all that popular here in eastern Canada, and I actually have no idea why. In Minnesota, where I grew up, basically every cabin, and many homes, have screen porches. Granted, the mosquitos are the size of sparrows there, but there isn’t exactly a shortage of biting insects here in the region around Ottawa. The bug season makes enclosed spaces awfully appealing for outdoor living throughout the wet northern temperate climates. In a lot of the modern architecture photos and articles that I’ve looked at, I often see whole walls that open to make indoor/outdoor spaces, and decks and porches seldom seem to have any bug protection. This may work in California, but that sort of design certainly does not fit well in a place where the biting insect season almost completely overlaps the warm months.
Most multi-story homes have the main living areas on the main floor, with bedrooms above. In a great many cases this really does make the most sense. One can enter the house and go straight into the more public spaces, with the bedrooms tucked away up a staircase. However, it isn’t so great if your home has a view that you would like to take advantage of, as those views generally improve the higher one goes, and I don’t think that a lot of people spend hours in their bedrooms admiring the views.
In our case, we had a perfect setup to flip the house upside down. We planned from the beginning to have a walkout basement lower level, and we had tremendous views that we wanted to be able to appreciate. Pushing the house into the side of the hill also meant that it was only five steps up from the driveway to the upper level. So while I don’t think that it is for everyone, I wouldn’t do it any other way if we were building again at this site. The advantages are that we are able to really appreciate the views that our hilltop site affords, the space is much brighter, and it tends to be warmer upstairs which is a boon most of the time (and conversely, the bedrooms stay cooler at all times of the year which I appreciate when I sleep). All that said, there is one significant drawback – even with some insulation to deaden the footfalls, it can be difficult to stay asleep downstairs when there is a 3 year old running wind sprints back and forth above your head at 6:00 in the morning.
Our downstairs is then taken up by three bedrooms, one full bath, and mechanicals/storage space. We kept the bedrooms to a relatively modest size, each at about 12’x12′. This is big enough to have a full set of bedroom furniture but leaves relatively little room to spare. Some people now put in massive bedroom suites, but it seems to me that bedrooms are mostly just for sleeping and not for hanging out. And just to show that I’m not entirely self-consistent, I’ve included a picture below of the windows that we put into the master bedroom. I couldn’t resist taking advantage of the view even if we don’t spend that much time in there appreciating it.
There are dozens of popular styles for homes, such as Prairie, Tudor, Craftsman, and many others. Though there are some cultural and climatic reasons for choosing one style over another, the better part of the decision making comes down to aesthetic choices. Through all phases of the design process, I spent a good deal of time looking at architectural and design websites, articles, magazines, and photos. I was particularly drawn to aspects of the contemporary style, and so making the decision really came down to that appeal. To really dig into the sort of places that I found inspirational, I found even more tightly defined terms like “modern rustic” or “mountain contemporary”. These styles really have become quite popular with those who build nice houses out in the woods, fields, and mountains. Staying within a given style lends a sense of continuity to a home, from the inside to the outside, and from room to room, though there are certainly some eclectic homes that stand the test of time as well. If you search around for terms like these in architectural magazines and websites, you’ll find no shortage of examples that have a similar feel to our own place, relatively modern looking with lots of natural wood, stone, and big windows to take in the views. I just hope that in 20 or 30 years time that our choices don’t look as dated as all of the 70’s lime green, orange, and dark faux wood paneling that my parents installed when they built their own cottage back in the day.
A few of the most influential architects and builders on our aesthetic choices are the following:
Finne Architects. Extremely high end custom contemporary homes. They are absolutely beautiful, but I don’t even want to know what the costs are. Nils Finne and his team make a large amount of built ins, custom furniture, and unique designs for each and every project.
Method Homes. A prefabricated home builder. Some of their home styles are quite architecturally similar to our own final design.
My wife and I both love natural wood finishes, and I am exceptionally fond of the bigger timbers used in timber framing. However, in the earlier part of our own design process, I learned why there are so few timber frames being built today. First, building with big timbers is expensive. The wood costs are significantly more, but so are the costs of cutting the traditional joinery (needed before the easy availability of strong metal nails and screws). Second, it is quite difficult to insulate a timber frame building. The most common way of doing so is to build the house twice; first build the timber frame, then build another full wall and roof assembly outside of that which can be insulated normally. At the same time, the timbers are beautiful. Many people generate a similar look with false beams or wrapping regular construction lumber in naturally finished boards, but just like what I mentioned about faux stone above, I find that many of these attempts can end up looking inauthentic or cheap.
With all this in mind, we found a few places in our home where big dimensional timbers made a bit more sense, using a building method commonly called a ‘hybrid’ timber frame. The first location was our screen porch. Here, there aren’t any issues of insulation to deal with, as the whole structure is just a shell to keep out insects, with cedar floors, plexiglass lower panels to prevent anyone from falling through, and screen above. Second, we used big beams to hold the roof trusses on the big overhangs. We put 4′ overhangs around the entire home, and though there are multiple ways to support this sort of detail, we did so with large douglas fir beams, on which all of the roof trusses rest (see the time lapse installation video here for a look at the work the fir beams do for the roof). Finally we used white pine beams for the floor joists and supporting beam for the second story. We were going to need to put in joists anyway, so we decided to use 4″x8″ joists, and a 10″x12″ supporting beam. This provides a beautiful ceiling for the entire downstairs level, and should be rock-solid for the lifetime of the house. So for the heavy beams that we included, they all serve very functional purposes, which felt like an important thing to me, that it was not simply decoration. For all of our timber work, we used simpler joints held together by screws rather than the traditional mortise and tenon joinery, which allowed all of the installation to go much more quickly.
Building for resilience:
Finally, I want to make some comments about building for the long-term. So many decisions in home building (and too many other domains as well) are made looking only at the short term. For builders, it usually makes the most sense to build the most inexpensive construction that they can get away with, and then invest more on those parts of a home that really catch the eye of the buyers, like the fancy kitchen, spa type bathroom, or big walk-in closets. People don’t tend to be very good at evaluating what is behind the final finishes, nor are they good at imagining what the future maintenance, replacement, utility bills, or other costs will be for a home. Further, people only own a given home for an average of 13 years, so any feature that doesn’t do well on the resale market is less likely to make it into the average home.
This is of course not a complete picture. The building code improves steadily, requiring constantly better insulation, air sealing, air quality and more. And there is a growing trend toward green building, emphasizing reduced energy use and healthier indoor air. Unfortunately, these are still relatively niche markets, and the average new home being built is far less than it could be.
For our own project, we built a place that we hope to never have to sell during a lifetime, and if things go really well, our kids will continue to use it well after we are gone. With those kind of goals in mind, it is much easier to think about a 50 year time frame, and to be able to justify the costs of doing things ‘right’ the first time around. If we’ve succeeded at this, we may have very little maintenance and renovation work to do on the house itself for decades to come. Only time will tell us if we succeeded. So rather than discuss all of the details individually, I just include a long list of the details that we included for the sake of long-lasting quality.
Steel through fastened roof. Should last in excess of 50 years
4′ overhangs on all sides of the building. Reduces the exposure of the siding and base of the house to sun, rain, and snow, which should extend the lifetime of the siding.
Great drainage and waterproofing around the house. Should keep all water away from the foundation indefinitely
Poured concrete foundation rather than cement block. Much longer lasting, and much more resistant to the elements
Low maintenance landscaping and plantings, should require little to no watering or fertilizer.
Cement board siding. Though after learning more, I would likely go with steel siding for the entire building. Steel has the same pros of fire and pest resistance, but has lower embodied energy, lasts longer and is more easily recycled
Real wood (white pine and sugar maple) for the trim, flooring, staircase and wooden interior doors. These should last much longer than hollow or fiberboard materials and can easily be refurbished rather than replaced if they receive any abuse
Low and zero volatile organic compounds (VOCs) in all of the paints and other finishes. These allow for much improved air quality, and I expect to see indoor air quality standards to become much more strict than they are today
Superinsulated, most insulation being mineral wool (Roxul)
We didn’t originally plan to do any formal energy modeling for our home. It actually only came about because of our relatively last-minute decision to seek LEED certification. One requirement of the LEED process is to do an evaluation of the energy efficiency of a home, and this includes a fairly complete description of the building’s size, orientation, insulation, electrical appliances, etc. Using all of this disparate information and applying some standard assumptions about how a typical family uses a home (e.g., amount of hot showers, thermostat temperature, etc.), energy modelers are able to put together estimates of total energy use for a home.
Below is our “Home Energy Rating Certificate”, which shows the overall estimates, including the major details about the home, the systems, and expected energy use. To boil a house down to a single number, many efficiency experts use the HERS rating. This is an evaluation of how much energy the modeled house uses as compared to a house that just meets the 2006 International Energy Conservation Code. Climate and house size are controlled for, so as to be better about comparing apples to apples. As you can see in the certificate, our home achieved a HERS score of 23, whereas the reference home is always counted as 100. While I won’t actually go through the calculation, this number is the percentage of energy that the modeled home uses as compared to the reference, with an adjustment for self-generation of power through things like our PV panels. In comparison to the ‘standard’ home, our place brings the energy demand down by over 70%.
The rough breakdowns in energy use in kWh/year are the figures that I find most interesting here. Our home is projected to use a grand total of 19271 kWh/year, with 4785 kWh coming from electricity produced by the solar panels, with the balance of 15465 kWh provided by propane.
So how does this compare to our actual use for the year of 2015 (well, November of 2014 to November of 2015)? During that time, we used exactly 400 gallons of propane, for a total of 10,800 kWh of energy. We also burned about half of a cord of maple and oak firewood, which provided roughly 3000 kWh of heat. The best measure of our solar electric use is actually the energy used by plug loads during the year, of 1400 kWh. This figure is actually a significant underperformance for our expected solar electric contribution for a couple of reasons. First, the batteries didn’t age well in their first year of use due to some overly deep discharge in their first months of service, and second, that more power was ‘wasted’ than expected, as excess power cannot be saved if it is not used and the batteries are full. I am putting together a system to use some of that excess power and will write about it once it is up and running. Needless to say, this puts our actual energy usage for the year at 15,200 kWh, much less than the model-predicted figure of 19271 kWh. This is no surprise, as we are inhabiting the home only about half of the time, and probably taking less showers and using less technological toys than the average household. I would imagine that if we were there full-time that our actual energy usage would end up quite similar to the model’s projections.
Another interesting set of details that came out of the modeling were estimates of heat loss through all of the different components of the housing envelope (See below – First document in English, followed by a more detailed one in French. Some of the text in the English is wrong in the columns but correct in the chart). To stay in kWh, I’ll work with the numbers from the French document. The total amount of heat needed from the active heating systems is 9286 kWh (25% of the reference home). Part of the reason this figure is so low is due to the passive solar heat gain coming through all of the windows, to the tune of 4306 kWh/year. Putting these figures together shows that over 31% of the total heating needed for this home is accomplished by sun streaming in the windows. I’ve taken just enough of a look at the passive solar heating literature to know that this is roughly as high as one should go with passive solar heating in a home unless one is willing to endure unwelcome overheating on warm sunny days in the winter and spring. Even with our place, I am finding that on bright sunny days in February and March that the upstairs of the house can exceed 30 degrees Celsius (86 Fahrenheit) with the heating turned off. I have actually found it to be good for the spirit to be able to open the windows and wear shorts on those blue bird days in February.
The other great thing about this heating breakdown is that it shows how much heat loss to expect from each component of the home. It is no surprise that the above grade walls are the biggest component, since they make up much more surface area than any other part of the home. The walls would have been one of the most expensive parts of the home to upgrade, due to the amount of materials needed to cover that much area. The next highest contributor is air infiltration, at 2783 kWh/year. When the house was half-complete a blower door test showed that we had an air-tightness of 1.47 ACH@50Pa, but as I outlined in this post, the house is probably tighter now and this heat loss lower than the model suggests.
The concrete slab and foundation walls, at 2314 kWh and 1435 kWh respectively, are probably the only places that I wish I would have added insulation. It would not have been that difficult or expensive to add thicker layers of rigid foam insulation, and I’m fairly sure that it would have been cost-effective to do this upgrade. I guess that one advantage of the current state of things is that the downstairs bedrooms are always cooler through the summer, making sleeping comfortable even on the hottest days of the summer without any air conditioning.
The Power of Solar
I just wanted to reiterate one more time the usefulness of both active and passive solar in reducing the need for other, usually fossil fuel, sources of energy. If we were to eliminate the solar gain through the windows and disconnect the solar panels, the model suggests that we would need 24,550 kWh/year of power from propane, or 909 gallons. However, we already get 4306 kWh of heat through the windows. The above models also don’t account for the new solar panels added this fall, which together with the original installation could produce about 9850 kWh of power per year . As I alluded to above, I am in the middle of putting together a system to use up much of this excess electric power for space heating in the winter and domestic hot water heating in the summer. If I were able to put all of this excess capacity to use, this would mean our total needs from propane drop to a projected 9074 kWh. Considering that we already use much less energy than the model projects, my hope is to cut propane use for next year from 400 gallons to 250 gallons or less. With continually improving technology and dropping prices, I can already see the day arriving, perhaps 15 or 20 years down the road, when it may be possible for us, and off-grid homes in locations like ours, to ditch the propane without breaking the bank. I’m looking forward to that day, when I have all of my energy needs met from the sun shining down from above.
So how close is our home to meeting the ‘Passive House’ standard?
One of the original inspirations for our home was the Passive House standard. I’ve discussed this a bit in another blogpost, but briefly, this is a standard for vastly reducing the energy needed to heat and power a home. That standard allows for 15 kWh/m2 of heating per year, which is quite difficult to meet for a single family home in the climate here in Ottawa, Canada. Even with all of the things that we did to build a better home, the model still suggests that we are at 47 kWh/m2 per year, so nearly 3 times the amount allowed for Passive House certification. There are just a small handful of homes that have reached this certification in eastern Canada, and some of the professionals that I’ve spoken to around here think that such a low heating requirement isn’t currently a reasonable goal in our climate. It is much colder here than in the area where these standards originated (mostly in Germany), where this number makes more sense. Here, the local homes that are pursuing certification need to have walls roughly two feet thick. We felt that it made more sense here to build a ‘pretty good’ house, and then make up some of the difference through such means as renewables. In the future, it is almost certainly going to become easier to meet and exceed the Passive House standard, as green building techniques improve and become more widely known, and as technological innovations continue to produce better products.
Anthony Mach, the architect that we worked with on our house, gave a presentation about our house in the spring of 2014, covering some of the basics of passive homes, passive solar design rules, and how our house fits with these design principles. This presentation was given to an architectural design class at the school, and acted in many ways as an introduction to green and high efficiency building for these students. Rather than explain it further, I will let the slides from his presentation speak for themselves, see the pdf linked below.
In years past, the mechanical systems and appliances within off grid homes looked quite different from typical grid tied homes. Electricity generation was extremely difficult and expensive at the home scale, so there was much less electrification. Instead, off gridders used other technologies like wood stoves, kerosene lamps, and propane powered appliances.
One can still find most of these electricity-light home appliances, including such things propane lighting and propane powered refrigerators. However, these systems are made at such a small scale and are in such small demand, that they are quite expensive and do not perform incredibly well. Thankfully, an off grid house today can maintain essentially all the comforts of on-grid living, as long as one is careful about making choices. Two trends have allowed this to happen. First, solar power generation and storage is falling quickly in price, and it is now possible to have a regular supply of electricity at a home for a manageable cost. The second trend is large increases in efficiency of all of the electronics used in our homes. The normal, high efficiency, often Energy Star approved, appliances and other electronics of today use just a fraction of the power of their predecessors.
Put all of these trends together, and it is now possible to use all off the shelf products from standard stores, as long as the most efficient of available options are chosen. The one thing that is difficult to do with electricity in an off-grid home is heating. Whether it be home heating, water heating, the kitchen range, clothes dryer, all of these are energy hogs and the electric versions are not affordable in today’s off grid home. In our case, we use propane to do most of this heavy lifting (though I hope to eliminate the propane at some point in the future). Below is a run-down of all of the systems that we have put into our home.
We have a propane range, one of the basic models that was available at the local Sears (the Kenmore 5.0 cu. ft. Freestanding Gas Range w/ Variable Self-Clean, Model #74132). This unit has 5 burners on top, and propane burners at both the bottom and top of the oven. This unit does require some electricity for full functionality. The range has electronic sparkers to light the burners, though these can be lit with a match or lighter if there is no power. The oven, however, requires a larger and more constant supply of power, as a heating element stays on at all times when the oven is heating. I have not been able to find the exact power draw for the stove heating element, but I think that it is around 200 or 300 watts. It would have saved a bit of electricity if there were a pilot light inside the oven, but these models are getting harder to find and are apparently not always as safe as the electrically controlled ovens.
A refrigerator is one of those modern conveniences that would be very difficult to live without. And with refrigerated and frozen foods, it isn’t possible to turn off the power when you are away, unless you empty out the whole thing. As I mentioned above, one can run a refrigerator on propane, but these units leave something to be desired when compared to a typical fridge. Thankfully we produce enough electricity to keep a fridge powered. We have a Kenmore 596.6938, a 20 cubic foot model that is rated to consume 459 kWh/year. There are a few fridges that have power consumption as low as 350 kWh/year (less than 1 kWh/day), but they were a bit small for a family that cooks a lot and does a fair amount of entertaining.
We wouldn’t have necessarily needed a dishwasher, but it is a nice convenience. We picked up an energy star rated Kenmore model 630, which Energuide lists as a 269 kWh/year expected power usage. We generally only run when full, and t requires approximately 1 kWh per load of dishes washed when run on ‘eco’ mode.
We chose a high efficiency front-loading washer, again by Kenmore. This is one of the more efficient models available. Front loading washers tend to outperform top loading models, and provide one additional benefit – an extra powerful spin cycle. By spinning at several thousand RPMs, the vast majority of the water is pulled out of the clothes before one even takes them out of the washer. This allows a very quick air drying, hung either outside on a line, or in the house on racks. We decided that it would not be worthwhile to try to add a dryer. Electric units consume too much electricity, gas dryers are more expensive, and we already were getting most of the drying done by the high speed spin cycle.
In any tightly built house, one needs to provide for ventilation. In older and draftier homes, a lot of air leaks into and out of a house just through little cracks around joints, windows, and doors, but with new high efficiency construction there is a strong risk of the air getting stale. Our home ended up very tight (see past post here), so we needed mechanical ventilation. This is accomplished by a heat recovery ventilator (HRV), which serves two purposes. First, the HRV circulates stale air out of the house while bringing fresh air in. All sorts of gases can build up inside homes, from cooking, off-gassing from materials, even simple human habitation, and these are vented to the outside when bringing in fresh air. Second, an HRV exchanges heat from the venting air with incoming air in a heat exchanger. This allows the home to hold onto more heat in the winter, and keep out some of the heat in the summer. We settled on the LifeBreath 155 Max, which sized nicely to our air circulation needs, while consuming only 40 watts on the low setting.
Just in the last 3-4 years, there has been a sea change in lighting, as LED technologies have become cost-competitive with the compact fluorescents and incandescents that came before. While still somewhat more expensive than these other choices, LEDs last much longer (often estimated around 20 years), and consume only a fraction of the energy. We put in all LED lighting to minimize electricity use. Some of it is in specialized fixtures, but most of it is screw in or pin type bulbs, and this was only a bit more expensive than other options available. When lighting up the house at night, the total lighting loads seldom exceed 100 watts.
We use propane to do our domestic hot water heating, with an indirect water heater powered by our propane boiler (see post about our heating system here). Our boiler has a set of heating loops that come off of it, and one of those loops goes inside the water tank. A heat exchanger consisting of a set of copper coils containing the heated glycol pass heat to the domestic water in the tank. Because this setup uses a relatively powerful boiler when heating the water, it is actually able to provide continuous hot water for such things as bathing. The water heater is set up to take precedence over space heating, so there is always a good supply of hot water.
Phone and internet system
While it was appealing to have no phone or internet at our home in the woods, it wasn’t practical. Both my wife’s and my work depend on being internet connected, and it can often be important to be able to make phone calls. However, since we are so far off the beaten path, we have no phone lines, and only a very weak cellular signal at our home. To remedy this situation, it took a few different steps. The good news was that the phone and internet systems combined require less than 10 watts to keep a constant and high quality connection.
To improve the cell phone reception, I set up a cellular signal booster which consists of several parts. First, there is an antenna mounted to the outside of the house which is pointed at the nearest cell tower about 5 miles away. From this antenna, a coaxial cable is run into the home into a cell signal amplifier, which is a box about the size of a typical modem. This is then connected to an interior antenna. When one uses a cell phone, the signal is received by the interior antenna, passing through the amplifier and exterior antenna to communicate with the cell tower. This system actually works very well, bringing the signal from one that is so weak that calls often cannot be connected, up to a very strong signal (5 out of 5 bars of reception listed on the phone).
To have a ready internet connection, we connected a cellular modem. This works just like any other modem, but instead of connecting through telephone or cable wires, it communicates over the cellular network just like a smartphone. Our local phone provider has a ‘family plan’ for data sharing, which we now share between smart phones for myself and my wife, as well as with the wifi network created by the cellular modem. Data is more expensive this way than through a wired connection, but as long as we don’t use the network for high bandwidth activities such as video streaming, it works very well.
It is a bit tricky to build an energy budget for an off grid home. It requires much more planning than with a typical home, as one has to figure out all of the details in advance. At the beginning of the planning process, I made a list of all of the electricity that we could expect to use, and then followed that up with trying to make sure that all purchase decisions would fit into that energy budget. As I mentioned in a past post, the one significant mistake we made was to have a heating system that required electricity to run – it wouldn’t be much for a typical house, but is tough for an off grid house in the winter.
It is currently much more expensive to generate energy off the grid than to buy grid power, so one has to be very careful to make everything as efficient as possible. If we were connected to the local utility, Hydro-Quebec, our electricity rates would be less than $.10/kWh, some of the cheapest power available anywhere in the world. However, with our backwoods location, generating our own power was the only viable option. When I estimate the cost and expected lifetime of all of our solar panels, electronics, batteries, backup generator, etc., our power cost will end up being much closer to $1/kWh, at least 10 times the cost of grid power. This means that economizing and conserving is the only way to keep the total cost of power reasonable.
Below I have attached a fairly accurate version of our energy budget updated to account for our first full year of use of our home. At all times we run a refrigerator, an HRV, the solar electronics, and a few other electronics that make up our internet and security systems. In the winter, the boiler also runs nearly every day to keep the house heated. On top of that, we have pretty bare bones usage of power as compared to a typical home, and I’ve done my best to reduce the vampire loads down to almost nothing.
Our total electricity usage for the past year was a bit less 1500 kWh, which makes an average of roughly 4 kWh/day. Our 1500 kWh of electricity usage is dwarfed by the typical household in Canada, which uses an average of 11,900 kWh (32.6 kWh/day). While our place is extremely efficient, I must make clear that one of the reasons our usage is so low is that we are only in the house a bit less than half of the time, as work and other responsibilities call us into the city far more often than I would like. If one factors in the power that we use in our rental in the city, we still are below average, but not by all that much. We are striving to reduce our energy consumption, especially of non-renewable energy, but it is a task that takes time to accomplish.
One other disclaimer to make is that our electricity usage still makes up significantly less than half of our total energy use. The technology is simply not yet available (at any sort of reasonable price) to heat a house through a cold, gray, and snowy Canadian winter with solar power alone. Propane and/or wood are an absolute necessity to be able to stay warm out in the countryside. With the fast dropping prices of solar, batteries, as well as improved building envelopes and heating technologies like air to air heat pumps, this may become a possibility a decade or two down the road, but the time is not yet ripe.
For better or worse, the property that my wife and I fell in love with was over a mile back down a private road, and our few other neighbors have summer-only cabins. There are no services of any kind that come down our road, no phone, no cable, no fiberoptics, and of course, no power lines. The neighbors heat with wood when needed, and handle cooking and a small amount of power generation with propane. I looked briefly into bringing power lines back to our site, but an off grid solution became the obvious choice when I realized that the price would greatly exceed $100,000 just to put in the power poles. I already had quite an interest in sustainable energy and solar power, so this provided just the impetus that I needed to pursue an off grid home.
I’ll list the vital statistics of our system first, and then say a bit about how the system has worked so far, as well as the updates that have already been implemented.
Our electricity generating system:
Photovoltaic panels: 12 Solarworld 235 watt panels (2820W in total) Additional panels (fall of 2015): 12 Jinko 250 watt panels (3000W total) Batteries: 8 Deka Deep cycle solar batteries, lead acid AGM 12V 265 Ah (a nominal 25 kWh storage) Backup generator: Generac Ecogen, 6 kW
Any electrical grid starts with power generation, and ours is no different. The majority of the time, all of our electricity needs are supplied by solar panels. However, there are times when the panels can’t produce enough power (at night and on cloudy days) when it is needed. Generally the batteries serve the role of storing enough energy to get us through a couple of days without much sun. When the battery charge gets too low, the backup propane generator turns on, sending power into the house via an alternator to be used both to power the house and recharge the batteries.
The electronics provide for energy transformations and communications. The charge controller takes high voltage power coming from the solar panels, and steps it down so that just the right amount and voltage (a bit over 48V DC) of power is passed on to the other systems. Most of this power is dumped straight into the batteries, which chemically store that electricity for later use. When power is needed for loads in the house, that 48V power coming from the batteries and charge controller is drawn into the inverter, which converts the power into the normal household power found in any home, 120V alternating current, which goes out through a standard breaker panel to the house. The inverter is actually an inverter/charger, so in addition to taking DC power from the batteries and solar panels out to the house, it can also convert AC power from the generator (or for others’ setups, the power grid) into DC power to charge the batteries. The Automatic Generator Starter is able to start the generator whenever the battery voltage falls below a certain level, ensuring that the batteries are never discharged too deeply. Finally the Combox provides an interface for controlling all of the other devices, as well as being able to connect to the internet, which I use to check the system remotely and send regular system status updates by email to myself.
Solar panel orientation
There is a simple rule of thumb that I learned from our solar installer when we were discussing our system setup, with the best orientation for stationary panels being due south, with an angle equal to one’s latitude on Earth. This maximizes the annual output of power from a given solar panel. We are at 45° north, so we ought to set our panels at the same angle to the ground. For our original panels, we were able to get this orientation, due south and at a 45° angle.
Through our first winter, I realized that there are some nuances to an off grid system in the northcountry that aren’t captured by that rule of thumb. There are two main problems with following this rule. The first is snow. It turns out that panels set at 45° don’t shed snow as well as I’d hoped. The snow will clear after a day or so of sunny weather, but while the snow is still there, no power is produced. Clearing them manually works fine, but we are not always there to do it. The second problem is that an off grid home is not in the business of producing the maximum total power over the year, it is about always having enough power available to keep the house running. Our summer power loads are extremely low, as no heating is needed, days are long and so little lighting is needed, and we are outside much more often. In the winter, when there is already less sun, our electricity needs are actually much higher.
These two problems have a shared solution, to set solar panels at a much steeper angle. This allows snow to shed off very easily, and squares the panels much better to the low angled winter sun. Of course it is possible to get around this problem with such things as seasonably adjustable solar panels, or the significantly more complicated sun tracking systems, but the simplicity (and reduced cost) of fixed panels is quite attractive. I would go so far as to say that if one is going to have stationary panels in the northern US or Canada on an off grid home, that orienting them for the winter is the best path to follow.
In our first two winters, we were overly reliant on our (poorly functioning) generator through the winter, and so earlier this fall, we added just such an upgrade, an additional solar array set at an angle of 65° from the ground. These should greatly reduce the amount of run-time that will be needed from the generator in future winters. As you can see from the picture below, the new panels also are turned a bit to the south-west, which is intentional. There is a better clearing in the trees toward the west, and so the new panels are turned a bit so that they will be receiving direct sun for a greater portion of the day.
Power generation through the year
Finally, I’ve attached the power production estimate that my solar installer created for me prior to installing the system. While a few details changed after these estimates were made, there is an incredible wealth of data here about our local solar resource, expected consumption of power at our home, the efficiencies of the various components of an off grid power system, and more. For any readers who may actually be considering building an off grid system, this is the sort of nitty gritty details that you will need to consider.