Solar Market Challenges
Residential and commercial energy conservation research has been an on-going process for the last several decades. The research scope extends from applying conventional and new conservation concepts to the development of active solar thermal energy systems. In general, the financial incentives to the user or to the manufacturer of such systems have not been sufficient to result in their wide-spread use. This problem was compounded by the negative visual effect of active solar systems. Accordingly, most of the research work has been financed by various government agencies. Furthermore, the relatively low cost of conventional energy during the last three decades has contributed to the lack of significant support for this research area.

Harnessing Solar Energy
The common procedure to harness the solar thermal energy falling on roofs is to use an active solar collection system. Standard active solar systems consist of three major subsystems: 1) a flat plat solar collectors subsystem, 2) a control unit subsystem and 3) a storage subsystem. An active solar collector system is capable of capturing approximately one third (depending on the temperature rise and the ambient temperature and the particular design of the collector) of the solar thermal energy received by its solar collector area. The most direct applications of such system are to provide direct space heating in case of air solar collectors. For liquid solar collectors, the thermal energy for space heating would be supplied through a heat exchanger. In both cases water heating is achieved through heat exchangers. Considerable amount of experimentation were conducted on storage systems using variety of material, liquid, solids, and phase change materials. According to the Government publications, the cost of an active solar collector system ranges from $30 to $80 per square foot of the solar collector area.

Other hybrid systems such as solar assisted heat pump systems in the parallel and series configuration were evaluated and tested during the late sixties and early seventy. No commercial scale product is yet available. Efforts to directly convert solar thermal energy to more usable forms have been only moderately successful but no commercial outcome.


Hindered Marketability
Three decades later, the commercial market did not bear any of the above Research and Development effort. The major problems that hindered the marketability of active solar systems are several