These solar water heating panels provide about 60 percent of the Kemps’ hot water.
THE RENEWABLE ENERGY HANDBOOK/AZTEXT PRESS
Twenty years ago, when my wife, Lorraine, and I decided to move off the grid, our motivation was simple. Lorraine wanted to move closer to her family, preferably to a piece of land large enough to offer some privacy and plenty of room to support her “addiction” to animals. A lot at the back of her family’s farm fit the bill (and the wallet). There was only one downside: It would have cost tens of thousands of dollars to connect the property to the nearest electric lines. The solution was obvious: Don’t connect to the grid and instead plan to run our house entirely with renewable energy. We put our plan into action, and have been enjoying off the grid living ever since. Here’s how we run our rural Ontario home using an absolute minimum of fossil fuel energy.
An Efficient, Off-Grid Home
We built our home to look like a traditional country farmhouse from the early 1900s, and added some passive solar features to reduce the heating and cooling load. For example, the large roof overhang on the front porch shades the house from direct sunlight in the summertime while allowing the low-angle winter sun to warm the house. We also made the home as energy efficient as possible. We insulated primarily with blown-in cellulose, manufactured from recycled paper products. For areas that were difficult to insulate in this manner, we used spray foam (urethane) insulation, which has the added benefit of forming its own vapor barrier. Other energy-efficient features of our home include solar-powered vent fans, radiant-barrier insulation, vapor and wind barriers, and careful joint sealing.
Our domestic water system is “off the grid,” too, and we’ve made it as efficient and eco-friendly as possible. We have a standard drilled well with a deep-well submersible pump and a large water-pressure accumulator tank to minimize pump cycling. Our fixtures are all low-flow or ultra-low flow, which keeps our water consumption well below half the Canadian national average of 91 gallons per person per day. Our septic tank has an effluent filter, and a leaching bed that allows our wastewater to percolate through the earth and right back into the water table. To keep the water clean, we have always used natural and phosphate-free cleaners.
Solar and Wind Power
Our electrical-generating equipment originally consisted of a photovoltaic (PV) sun-tracking array with a peak electrical rating of 1.2 kilowatts. This array is composed of 16 individual PV panels rated 75 watts each. We also installed a Bergey 1.5 kilowatt wind turbine on a 100-foot guyed lattice tower.
Rounding out the electrical-generating mix is a 10 kilowatt diesel generator, which we run on between 30 and 100 percent biodiesel, depending on the ambient temperature. We would prefer to use 100 percent biodiesel all the time, but we have to add some diesel to the fuel mix. Biodiesel doesn’t work well in extreme cold, and in our location, winter temperatures can be as low as minus 22 degrees Fahrenheit.
The PV panels provide approximately 85 percent of our total annual electricity requirements, while the wind turbine provides 10 percent and the backup generator provides the remaining 5 percent or less. The electricity feeds into a battery bank with a gross capacity of approximately 3,500 amp-hours. Low-voltage power from the batteries feeds into an inverter bank with a total output capacity of 6 kilowatts, which in turn supplies household electrical needs.
Getting to Zero Carbon
My experience has led me to conclude that many people do not live “off grid,” they live “on propane.” Anyone who considers living off the grid quickly becomes aware that large, heat-producing appliances such as stoves, clothes dryers and water heaters use a lot of electricity! In most cases, people choose to run these appliances with propane or other fuel sources because it’s cheaper than installing a solar or wind system large enough to power these energy hogs.
A quick review of most off-grid homes shows that 90 percent or more of the total energy budget is used for heating, hot water and cooking. That is, a typical off-grid home relies on renewable energy for less than 10 percent of its total energy needs. Although propane is a relatively clean burning fuel, it is nevertheless a non-renewable resource that releases carbon dioxide when it is burned. Always up for a challenge, Lorraine and I were determined to reduce our propane consumption to zero.
By using a woodstove to heat our home, we eliminated the need for propane for space heating. Wood is a carbon-neutral way to heat your home. Trees absorb carbon dioxide as they grow. When they die and rot on the forest floor, they give off the same amount of carbon dioxide and heat as they would in our woodstove — we just accelerate the process.
At first, we used some propane to heat our water and for cooking. As we started to move away from propane-powered appliances, our electrical requirements increased somewhat, so we added two 165 watt panels, mounted along the top of the array. When we decided to kick the propane habit, we added a second solar array, bringing our total PV-generating capacity to approximately 2.7 kilowatts. We also increased our battery capacity.
Many small, application-specific kitchen appliances consume relatively little electricity and can easily replace propane-fueled appliances. We already had many of the electrical kitchen appliances that we needed, including an electric kettle, toaster, microwave and small convection oven. We also purchased an energy-efficient induction cooktop. The beauty of this unit is that the majority of the thermal energy remains in the food, while a similar gas stove may emit as much as 70 percent of the generated heat into the air. The induction unit is especially handy during the summer months when there’s a lot of solar energy to burn and little impetus to heat your house. Our “two-burner” unit cost less than $200.
We replaced our propane oven with a combination of other options. During the cooler months, our wood cookstove is always nicely preheated and ready for whatever we are preparing. Rather than finding an older refurbished unit, we installed an updated and airtight replica of grandma’s traditional wood cookstove, which includes a water heat-recovery unit. The cookstove can therefore do triple duty during the cooler months: heating the house, cooking our food and providing hot water. We use the microwave and electric convection oven for cooking during the summer months or to provide more cooking capacity in the winter.
Solar Water Heating
I decided to develop a hybrid system that would use the ample summer sun when it was available, while drawing additional heat from our two woodstoves in the cooler months. For the standard solar water heating system, I chose to install a vacuum-tube-based collection system rather than a flat plate design. Vacuum tube systems excel in extremely cold temperatures and can produce the high water temperatures I desired.
Our solar electric system also plays a role in water heating. Most homes use less electricity in summer than in winter, meaning that batteries are often fully charged before lunchtime. Standard solar electric system designs simply shut off as soon as the batteries are full, wasting a large amount of free energy. I developed a means of routing the excess solar energy to an electric water heater storage tank.
The solar thermal system produces approximately 60 percent of our annual hot water production, with the solar-electric and wood-fired systems providing the rest. This system works beautifully, providing plenty of guilt-free hot water for our hot tub and for almost endless showers.
You Can Do It, Too!
I’ve spent the last two decades upgrading and fine-tuning our home’s energy system in my quest to improve its efficiency and reduce our footprint on the planet. But back when we decided to go off the grid, much of the technology was still in its infancy. I am amazed at the variety and quality of equipment on the market today and how quickly it continues to improve. For most homeowners this equipment can be installed by a dealer and function in the background with only a modest amount of attention — unless you’re like me, and can’t resist the urge to tinker.
Not only is choosing renewable energy easier today than it was two decades ago, there are even better reasons to do it. As society better understands the true costs and environmental impacts of nuclear power, tar sands, coal and other fossil fuels, powering your home from renewable sources (whether on or off grid) is not only good for the planet and your pocketbook, it’s good for your peace of mind as well.
Resources for Off-the-Grid Living
The Renewable Energy Handbook by William Kemp
The Homeowner’s Guide to Renewable Energy by Dan Chiras
Solar Water Heating by Bob Ramlow and Benjamin Nusz
Find Solar Directory
Get information on solar electric systems and find solar installers near you.
Wind Powering America
Learn more about wind power and whether it’s a good option for your home.
Build It Solar
Find plans for home energy projects.
Find products for off-grid living.
MOTHER EARTH NEWS Renewable Energy Page
Read about 40 years’ worth of renewable energy projects.
William Kemp develops power-generating systems for hydroelectric utilities and biomass cogeneration. He has written several books on home-scale renewable energy.