'6GW of concentrating photovoltaics by 2020'
Concentrating photovoltaic (CPV) systems based on multi-junction solar cells will play a major role as future energy sources.
That's one of the conclusions of a new report on all forms of concentrating solar power published by the Prometheus Institute for Sustainable Development, an influential think-tank in the photovoltaics industry.
"Finally, the dawn of large-scale concentrating solar power is here, and the forecast shows hardly a cloud in the sky," the report states.
And although this might sound a little whimsical, the 145-page report does include some hard data and a healthy dose of realism: "While future market shares of the various [concentrating] technologies cannot be known, it is pretty clear that the collection of solar technologies will soon be cheap enough to penetrate deeply into the need for expensive daytime power."
The document does however make some predictions on the future market for the various types of concentrator technologies, based on the location and size of installations.
For CPV, which includes systems based on both multi-junction III-V and silicon cells, 6 GW of utility-scale installations are predicted by 2020. These will likely be in areas enjoying the very highest solar irradiance (greater than 2200 kWh/m2 per year), and deliver between 100 kW and 1 MW per installation.
Smaller installations and areas with lower solar irradiance will remain dominated by conventional photovoltaic technologies, while the largest utility applications will tend to use thermal concentrators, because it is much easier to store the heat that is generated. At the moment, it is impossible to store photovoltaic electricity, so CPV will only be useful for topping up the grid to meet peak electricity demand during the daytime.
"In terms of the location, it turns out that latitude of the installation matters a great deal," the report adds. In a case study on the cost of various types of installations, the report authors looked at the different options for Tucson, Arizona and Seattle, Washington.
At the moment, CPV is by far the most expensive solar technology available for either location. According to the standard levelized cost of electricity (LCOE) metric, CPV would cost $0.30 per unit at the moment in sunny Tucson, and nearly $0.70 per unit in rainy Seattle.
But by 2015, CPV is expected to be cost-competitive with other forms of solar in both cities. At $0.30 per unit, CPV will likely still be far too expensive to power Seattle, but in Tucson the projected LCOE of $0.13 per unit would look much more economically viable.
"CPV technologies will suffer from slower ramping and scale, but should become competitive at the utility scale within the next decade," the report concludes.
• The 145-page report Concentrating Solar Power "“ Technology, Cost, and Markets is available now from the Prometheus Institute for Sustainable Development.
