Cost

In high volume, REhnu projects an installed cost of $1/watt, low enough for large-scale adoption without government subsidy.

REhnu has set as its targets for high-volume production an installed capital cost of $1/watt and a levelized cost of energy (LCOE) of $0.05/kW-hr. REhnu’s goal is cost parity with fossil fuel by 2020. The three main cost elements for REhnu’s solar farms are 1) the generator components, 2) assembly and installation, and 3) operations and maintenance. The same choices that lead to good environmental stewardship also lead to low cost for all three elements.

The REhnu system has been designed from the outset with these targets in mind. The cost of generator units has been minimized by the design, which allows for separate manufacturing processes for the different components. The separation facilitates the use of inexpensive materials in lightweight structures; it also allows the concentrator cells to be very compactly packaged and replaceable.

The generator units are easy to assemble, requiring minimal custom equipment or skilled labor. The process is flexible and much of it can be carried out off site. Operating and maintenance costs are comparable to other PV and CPV systems and are largely confined to mirror washing. Both tracking and cooling systems are robust and designed for the 40-year life of the project. The compactness and modularity of the power conversion unit (which includes the receiver) facilitates a “spare-swap” maintenance strategy for unforeseen issues. More important, it facilitates cost-effective upgrades to higher performance units as multi-junction cell technology continues to advance.

Reality Check: Comparing REhnu’s generators to pickup trucks

Generator units for large-scale farms will be mass-produced in a volume comparable to that of pickup trucks, thus we can expect similar economies of scale. A pickup truck weighing 3 tons and delivered to the dealer retails for around $30,000, i.e. $10,000 per ton. A generator unit complete with pedestal and foundation weighs about a ton, but is far less complex and is therefore easier and cheaper to build, and will therefore cost less than $10,000. By 2020, with cell efficiencies > 50%, we project an output of 7.5 kW per generator, and thus a cost per watt of output power that closely approaches our $1/watt target.