Is bigger better when building solar PV power plants?
When looking at historic data in the U.S., no. But when considering other sources, perhaps. Ultimately, “community scale” solar is likely to provide the best combination of affordability, speed, and opportunity for local economic benefit.
There are two good sources of solar installed cost in the U.S. market, the California Solar Initiative (CSI) dataset, which spans from 2006 to 2011 and the Lawrence Berkeley Labs’ 2010 report Tracking the Sun III. The following chart illustrates the cost per Watt to install solar PV projects, based on a range of system sizes.
In the historic data of installed costs, almost all the economies of scale for solar are captured at a project size of 10 kW. But in the Clean Coalition data, the savings from building bigger continue strongly through the 100 kW size range.
Their data are not alone. In the German feed-in tariff, solar PV producers are paid a fixed price per kWh generated, with prices set according to the location of the solar PV plant (roof/ground) and by size (small, medium, large, etc). Overall, Germany has cheaper solar, with average installed costs for < 100 kW rooftop PV installations of just $3.40 per Watt (20% less than comparable U.S. projects). Their economies of scale are also strong, with the cost of solar falling most rapidly for projects over 1000 kW in size.
Source: Clean Technica (http://s.tt/1344Y)
