Solar electricity is a fabulous technology—long-lasting, productive, low-impact, and cost-effective. And it’s often the go-to answer when people want to move toward a more environmentally sound, resilient energy source. But home and business owners have several renewable energy (RE) options, whether their motivation is a smaller environmental footprint, stabilized energy costs, or preparation for an uncertain future.
Heating and cooling is typically a building’s largest use of energy, so it’s worth focusing carefully on how to reduce this load before working on covering it renewably. Insulation and air-sealing are not glamorous, but they can dramatically reduce your home’s appetite for space conditioning. Blower-door testing and thermal imaging can be real eye-openers, showing how much energy is being used to heat and cool the great outdoors, and pointing to how to reduce the waste.
It’s worth considering a number of RE options for heating. Passive solar design features—careful choice and placement of glass, thermal mass, overhangs, and overall home design—can supply some or most of your heat, depending on your climate. Wood heat may be an option for you as well. And the high-tech, low-energy prize might go to minisplit air-source heat pumps, which efficiently and comfortably heat and cool a home with minimal cost and intrusion into the building envelope. These modern space-conditioning systems “pump” heat from the outside air, using 1 kilowatt-hour of electricity to move 2 to 5 kWh of heat into your building.
Water heating is often a home’s second largest energy load, and can be well-served by a solar water heating system. On the low-tech end, heat-exchanging coils in a wood heater can provide domestic water heating in winter. Heat pumps can also be used for this application.
Choosing and using electrical loads carefully to reduce energy consumption should be a primary component of any RE strategy. From lighting to computers to kitchen appliances, many energy-efficient models are available. Sometimes, avoiding electricity use—for example, by using a solar oven, food dehydrator, or line-drying clothes—can be your best bet.
Three basic ways of generating electricity on-site are solar-, wind-, and hydro-electricity. Hydro sites are rare, but if you have falling water on your property, it’s the first resource to assess. Wind-electric systems are challenging, but may be the best option if you have a good resource, and are determined to do the maintenance. Solar energy is available to the largest number of buildings, and modern, batteryless solar-electric (PV) systems are durable and reliable.
Even if you don’t have the resources or the budget to tap RE directly, you can still buy “green energy” from most utilities, or support renewable production via purchasing RE credits or “green tags,” or invest in solar or wind farms.
Exploring options will show many ways to reduce energy usage through efficiency and conservation—and ways to tap clean, local RE.
—Ian Woofenden, for the Home Power crew