he sun is an excellent source of radiant energy, and is the
world’s most abundant source of energy. It emits
electromagnetic radiation with an average irradiance of 1353
W/m2 on the earth’s surface [1-2]. To put this into
perspective, if the energy produced by 25 acres of the
surface of the sun were harvested, there would be enough
energy to supply the current energy demand of the world [3].
When dealing with solar energy, there are two basic choices.
The first is photovoltaics, which is direct energy conversion
that converts solar radiation to electricity. The second is
solar thermal, in which the solar radiation is used to provide
heat to a thermodynamic system, thus creating mechanical