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Home Solar Cheaper Than Every Concentrating Solar Power Plant

| Written by John Farrell | 3 Comments | Updated on Jan 13, 2011 The content that follows was originally published on the Institute for Local Self-Reliance website at

A residential rooftop solar PV system in Los Angeles, CA, has a cheaper cost per kilowatt-hour of electricity delivered than the most cost effective, utility-scale concentrating solar power plant. 

In 2010, a buying group called Open Neighborhoods openly advertised an opportunity to get a solar PV system installed for $4.78 per Watt (not including any tax credits, rebates, or grants), a system that would produce approximately 1,492 kilowatt-hours (kWh) per year (AC) for each kilowatt of capacity (DC). 

Based on the best available public information about the costs and performance of operational concentrating solar thermal power plants, the PS10 solar power tower – an 11 MW installation in Spain – has the lowest levelized cost of operation of any concentrating solar power plant that produces electricity.  PS10 had an installed cost of $4.15 per Watt and produces 2,127 kWh per kW of capacity. 

However, due to higher operations costs and a higher cost of capital (8% rather than 5%) for a concentrating solar power plant, the levelized cost of the residential rooftop system (17.3 cents per kWh) is less than that of the power tower (19.9 cents per kWh).

This analysis also does not include any transmission infrastructure or efficiency losses, either of which would increase the levelized cost of the concentrating solar power plant.  It also did not include the lower price point from Open Neighborhoods, which advertised a possibility of driving the price down to $4.22 per Watt (driving the levelized cost down to 15.3 cents per kWh).

The Southern California Edison project, also featured in the chart, is another example of low-cost distributed solar PV, with the 250 MW project spread across commercial rooftops in 1-2 MW increments but still achieving large scale. 

Ultimately, this data further confirms that distributed solar can be delivered less expensively than centralized solar power. 

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About John Farrell

John Farrell directs the Energy Self-Reliant States and Communities program at the Institute for Local Self-Reliance and he focuses on energy policy developments that best expand the benefits of local ownership and dispersed generation of renewable energy. More

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  • Bob Wallace

    Rooftop is currently less expensive and likely to stay that way based on expected efficiencies in panels. But concentrated solar fills a different role than rooftop.

    Concentrated power can store heat for the higher demand hours after the sun goes down. It can even store heat for the days the sun fails due to cloud cover. Furthermore it can switch to natural/biogas for its heat source in order to provide when the sun fails and storage is exhausted.

    That ability to produce when rooftop won’t makes concentrated solar power valuable. I expect the long term grid will have a mix. Just like now the grid will not be fed only by the single cheapest power source.

  • Joy Hughes

    Another thing to watch is the fast drop in off-grid solar prices. When people are ready to jump off the grid, trouble for the power companies!

  • J.P.Gupta

    Dear Sir, In the article above you have compared two different things on one platform which is not ethical not technically correct and not in practise any where in this world. You have done a wrong thing and wants to make it more wrong by this article. No one is going to accept this. Your comparison is like monkey and donkey or a lion and elephent and so on. If you want a correct comparison do write me at above and get it. Thanks JPG