Passive Solar Energy: An Old Idea We Can Use Today
Solar electric panels may get more attention than passive solar energy but don't underestimate the power of passive solar.
Not only is it less expensive to put it to work but it may be able to do more for you than those shiny photovoltaic panels you've been drooling over.
So what is passive solar energy?
It is the solar energy you harness with home design, home orientation, and regular building materials. No additional mechanical equipment is required.
Sound simple? In many ways it is. No space age equipment or understanding of volts and amps is necessary. In fact people have been taking advantage of passive solar for over 2500 years.
Back then the Greeks planned entire cities to give each home access to the sun in the winter months. The homes would be open to the south where the sun shone and they would have more protection in the north to keep out the cold winds.
That's still the basic idea of harnessing passive solar today:
Put a lot of windows in the south
Don't put many windows in the north
Incorporate materials like stone and concrete that will absorb the sun's energy and release it after the sun goes down
(The diagram below should make this a little more clear.)
The only thing that has changed since the time of the ancient Greeks is the material used to capture the sun's energy. Things like low-emissivity windows and more effective insulation have made things a little easier.
If you plan on incorporating passive solar power into your house plan you'll want to know about:
Isolated gain
and
Direct gain
Isolated gain refers to the use of a sunroom or other area which is specifically designed for passive solar collection.
Direct gain is a little simpler in that it doesn't involve any special construction. It usually just involves having south facing windows and masonry walls or floors to absorb the solar energy.
If you have the right piece of land and live in a moderate climate you could meet all your heating needs with passive solar. Even if this isn't possible for you, incorporating passive solar energy into your home design could save you money and make your home a lot more comfortable.
The only thing that has changed since the time of the ancient Greeks is the material used to capture the sun's energy. Things like low-emissivity windows and more effective insulation have made things a little easier.