Small solar-electric systems powered by parabolic trough
collectors can satisfy an important renewable energy market segment. System
installations in the range of 100 to 1000 kWe are of particular interest
because: a) a ready market has long been recognized for this size range, b)
this size range is not presently well satisfied by other solar technologies,
and c) parabolic trough technology is mature enough to satisfy this market need
in the near term. Steam turbine cycles are not well suited to this size range,
but this range is well matched to organic Rankine cycles (ORCs). And since both parabolic trough solar
collectors and ORC systems can be highly modular, the combination offers a high
degree of flexibility to meet a variety of small power applications.
Because of the high-temperature capability of the POWER ROOF™ system,
conversion to electricity is also a viable option, particularly
where friendly utilities are in need of summertime peaking power
or in remote locations of the world where no other cost-effective
or reliable option exists.
Currently on the market are organic Rankine systems that are
used for conversion of thermal energy to electricity in the smaller
systems (less than 5 megaWatts). However, higher the efficiency
systems are currently available for systems above 5 megaWatts.
In addition, current development is on going be other companies
and government agencies, which will improve the possibilities
for reduced maintenance and first costs as well as increased efficiency
for conversion equipment.
Overall,the preliminary cost estimates and system performance analyses indicate that
the delivered energy cost (in terms of a levelized energy cost without allowing
for tax credits, depreciation benefits, emission credits, or any other
incentives or rebates) of a 100 kW trough-powered ORC system can be under
$.20/kWh. The price of diesel power can be $.20/kWh or more, and these diesel
engines are in common use for remote power applications. Trough-driven ORCs
offer a remote power source that is competitive with diesel, more reliable than
wind systems, and more cost effective than PV.
Power Roof Applications:
