Solar Thermal Vs Solar Electric - What is the Difference?

Systems generating electric current from energy in thehome itself.
sun's rays are referred to as photovoltaic (PV forSolar thermal collectors look very similar to PV
short) or solar electric. They are sometimes confusedmodules - they are both flat panels roughly 3' by 5' in
with solar thermal systems because they look similarsize. Solar thermal collectors do not have the shiny
and are often mounted on roofs of homes, sometimesappearance of PV modules, which is one way to tell
even integrated together into what appears to be athem apart. Another telltale sign is the presence of
single array.plumbing, rather than wiring (which you usually can't
Photovoltaic Systemssee from the ground anyway), leading from the panels.
A PV system creates electricity which can be usedA solar thermal system is a closed-loop system
by the electric loads in your home. PV systems canwhere a liquid such as glycol circulates through the
create electricity thanks to the photovoltaic effect.collector on the roof. As it does, the sun is beating
When the sun strikes the silicon PV cells, electrons aredown on the collector and warming the liquid flowing
excited and want to get on the move. The wiring ofthrough it. The heated liquid then travels to the home's
the PV array corrals these electrons and marcheshot water heater and transfers its heat energy to the
them to the inverter, where the combined current iswater in the heater. This is basically heating the water
converted to AC and sent to the appliances in yourfor free, rather than paying for electricity or gas to
home or back to the power grid. PV modules are flat,heat up the water. (Instead of your water heater, the
glass-encased panels that often have a shiny bluish orheated liquid could be used in a similar way to heat
black appearance. Typical PV systems combine 10 toyour swimming pool.)
50 of these modules into an array.Both solar thermal and PV are excellent means of
Solar Thermalharnessing some of that free power from the sun, and
A solar thermal system uses energy from the sun toboth are eligible for generous rebates.
heat water used in a home or pool, or for heating the