Regulating Your Home’s Climate with Solar Techniques

You can harness the power and heat of the sun — the planet’s most sustainable energy source — to provide most of your needs for heating, cooling, and daylighting with relatively little cost to you and a great carbon saving for the Earth.

Passive solar energy techniques

Passive solar design takes advantage of the fact that the summer sun is higher than the winter sun. Overhangs shade the building from the summer sun, keeping it cool. The same overhangs allow the lower winter sun to enter the building and heat an interior thermal mass wall.

Passive solar design works in most climates, but it works best in areas with seasonal changes in weather. A sun-facing, thermal mass wall behind some glass is called a trombe wall. The space between the glass and the wall fills with hot air. Vents at the top and bottom of the wall control this hot air, allowing it to be used to heat the building.

The best approach to passive solar is to use the principles to influence and shape the design of your home. Although considering passive solar during the initial design of your home is best, even an existing building can benefit from these ideas. Passive solar systems don’t add to the cost of the building, and you’ll see an immediate improvement in your energy use.

Active solar energy techniques

Active solar is a design strategy for high-performance, ultra-energy-efficient buildings. Active solar incorporates all the elements of a passive solar design with additional mechanical equipment, such as pumps or fans, to take advantage of the heat from the sun. This equipment can include some elaborate technologies, such as:

• Motorized shades: Timers and sensors control when window shades are raised and lowered, which controls heat gain from the sun.

• Solar trackers: Solar panels turn throughout the day to follow the path of the sun. This increases the output of the solar panels.

• Vents: Thermostats and sensors control vents, which open to allow warm air into or out of the house.

Sharing solar energy around a neighborhood

Solar panels capture the sun’s energy as heat and transfer the heat via piped fluid into an in-ground holding system (a geothermal application) until it’s needed. In smaller communities, the heat is distributed through pipes to buildings throughout the community to provide warmth. In other applications, the heat drives a central steam generator to create electricity.

A solar thermal–geothermal system can heat a neighborhood.