This month a team of students from the Stevens Institute of Technology won the Department of Energy’s biennial Solar Decathlon for building the best solar-powered home. Inspired by Hurricane Sandy, the SURE HOUSE, which stands for SUstainable + REsilient, is designed to continue to produce electricity during blackouts by using a solar array in combination with a 60s-style beach house design and boat building materials. The house uses 90 percent less energy than its conventional counterparts and can even supply neighbors with emergency power for electronic devices.
The Solar Decathlon illustrates the Department of Energy’s focus on developing solar technology as a solution for America’s energy future. Solar photovoltaic panels now cost half of what they did in 2011, a trend the DOE seeks to advance with a $53 million research initiative, announced last year, to drive solar energy costs down even further and cut carbon pollution. The DOE estimates that there is now enough solar power being generated every year to power 3.2 million average American homes. Here are a few ways you can use solar power to cut your energy costs and reduce your home’s carbon footprint.
Heating consumes about half the energy of the average home, but you can cut this cost in half by using passive solar heating and cooling, according to the Department of Energy. This strategy uses a home’s location and materials to economize energy use. Active heating strategies add the pumping of solar-heated air or fluid through a home. Relying entirely on active heating is not usually cost-effective, so it is usually used to supplement passive heating.
For existing homes, start with an energy audit before pursuing any solar installations so that you can identify your most efficient potential improvements. When designing new homes, a passive energy strategy requires that part of the south side of your home has an unobstructed view of the sun. Your building designer will need to factor in considerations such as the orientation and size of the windows, the thermal energy absorbed by other materials in your home, how absorbed energy will be distributed through your house, and how to use features such as roof overhangs to prevent summer overheating. After your home is built, be sure to keep south-facing glass clean and to avoid blocking sunlight from hitting heat-absorbing walls or concrete slab floors.
Water heating, your home’s second-biggest energy cost, can also be done more efficiently by using solar power. Here you can select between passive and active systems. The cheapest type of passive option is an Integral Collector Storage (ICS) system, where a solar-heated water storage area heats cold water flowing through it. In more expensive thermosyphon systems, collected warm water rises through a higher storage tank as cooler water sinks. Active systems add circulating pumps and controls to circulate water either directly or indirectly using a heat-transfer fluid and heat exchanger. Which option is best for you depends on your solar resource, climate, and budget.
Using solar-powered lights to illuminate your yard is one of the easiest ways to use solar energy. Have a pool or a hot tub? Save money on your electricity bill and switch to solar power to cut the cost of heating your outdoor pool or hot tub.
In Your Car
For the first time, this year’s Solar Decathlon entrants were required to design their homes to generate enough energy to power a battery-electric vehicle in addition to the residence itself. Contest rules did not permit contestants to store electricity generated from the home’s roof in the car’s battery, but this could be easily done. Meanwhile, Ford has been working on improving the efficiency of solar panels in the roofs of electric cars, according to Consumer Reports. Soon you may be able to power an electric car from your home and car solar panels and leave no carbon footprint.