Commercial energy audits are recommending solar thermal installations with increasing frequency. The reason is that solar thermal technologies are increasingly cost effective in heating and cooling (through use of chillers), and they can also produce electricity.

Truth be known, quite a few commercial energy auditors get pretty excited over solar thermal when they find a good opportunity to recommend it. Not only are these systems about as "green" as you can get . . . in just the right situations they can provide an impressive return on investment. Some other advantages include:

Advantages of Solar Thermal Systems

* Solar thermal energy is clean, effective and efficient.

* Using solar thermal energy to heat water (alone) can dramatically reduce your
electricity bill. Add air conditioning and maybe electrical generation and the energy
cost savings can be truly impressive.

* Solar thermal systems are available in a wide range of technologies and price points.
Large installations may require more expensive solar parabolic or solar trough
reflectors. Small installations may utilize a less expensive rubberized collector mat.

* Some solar thermal equipment is approaching life cycles of 25 years and more.

* Solar thermal provides reliable power in locations that are from natural gas lines
and an electrical grid.

While most of today's solar thermal systems serve homes, offices and industrial buildings, the technology necessary for building large solar thermal power plants is likely to be availabe in the very near future. That technology could replace a great many coal and oil-fired power plants.

Disadvantages of Solar Thermal Systems

* As is the case with solar photovoltaics, the economics of solar thermal are not yet
perfect. High performance systems are expensive (and lower performance systems,
while less expensive, are often of lower quality and not worth installing).

* There are a number of questionable products on the market (and less than
knowledgeable contractors who are ready and willing to install them).

* As is the case with any solar system, most (but not all) solar thermal systems require
a great deal of space.

The Bottom line on Solar Thermal

For now, the bottom line on solar thermal seems to be that, if a commercial energy audit indicates that it may be financially feasible, integrating solar thermal into your energy efficiency project is worth a hard look.