A Review of Solar Photovoltaic Concentrators

Table 1

Advantages of concentrating over flat-plate systems for large PV installations [22].

Lower cost	GaAs dish concentrators are projected to produce electricity at 7.4 cents/kWh by 2010, whereas thin-film modules are projected to be at 9.6 cents/kWh. If thin-film module prices come down from the assumed $75/m^2 to $35/m^2 at 12% efficiency (29 cents/W), then thin-film electricity cost would equal GaAs dish cost.
Superior efficiency	Concentrators are the only option to have system efficiencies over 20%. This reduces land utilization as well as area related costs.
Higher annual capacity factor	Tracking provides for improved energy output. Once the expense of tracking is incurred with flat-plates, the leap to installing concentrator modules is small.
Less materials availability issues	Concentrators use standard construction materials for the bulk of their requirements. Flat-plate systems have serious concerns over material availability: silicon feedstock, or indium in the case of CuInSe2.
Less toxic material use	Many thin-film concepts use quite toxic materials such as cadmium, and so forth.
Ease of recycling	The trend in modern mass-product manufacturing is to make a product as recyclable as possible.; Concentrators are composed mainly of easily recyclable materials, steel, aluminum, and plastic.; Recycling flat-plate modules will be much more difficult.
Ease of rapid manufacturing capacity scale-up	Existing semiconductor manufacturing capacity is more than sufficient to supply projected cell requirements. The remaining manufacturing is comprised of rather standard mechanical components.; This greatly reduces capital requirements compared to flat-plate.
High local manufacturing content	Aside from the cells, the remaining content of concentrator systems can be manufactured worldwide, and close to the final point-of-use.