Solar Energy
Solar technologies tap directly into the
infinite power of the sun and use that
energy to produce heat, light, and power.
Passive Solar Lighting and Heating
People have used the sun to heat and light
their homes for centuries. Ancient Native
Americans built their dwellings directly
into south-facing cliff walls because they
knew the sun travels low across the southern sky in the Northern Hemisphere during the winter. They also knew the
massive rock of the cliff would absorb
heat in winter and protect against wind
and snow. At the same time, the cliff-
dwelling design blocked sunlight during
the summer, when the sun is higher in the
sky, keeping their dwellings cool.
The modern version of this sun-welcoming
design is called passive solar because no
pumps, fans, or other mechanical devices
are used. Its most basic features include
large, south-facing windows that fill the
home with natural sunlight, and dark tile
or brick floors that store the sun’s heat and
release it back into the home at night. In the
summer, when the sun is higher in the sky,
window overhangs block direct sunlight,
which keeps the house cool. Tile and brick
floors also remain cool during the summer.
Passive solar design combined with
energy efficiency will go even further.
Energy-efficient features such as energy-
saving windows and appliances, along
with good insulation and weatherstripping,
can make a huge difference in
energy and cost savings.
Solar Water Heating
Solar energy can be used to heat water for
your home or your swimming pool. Most
solar water-heating systems consist of a
solar collector and a water storage tank.
Solar water-heating systems use collectors,
generally mounted on a south-facing roof,
to heat either water or a heat-transfer
fluid, such as a nontoxic antifreeze. The
heated water is then stored in a water tank
similar to one used in a conventional gas
or electric water-heating system.