Archive for February, 2008

Is PV power economically viable?

Thursday, February 21st, 2008

A San Jose Mercury News report today entitled Solar panels a ‘loser,’ professor says drew a lot of criticism from the solar industry. The gist of the report is that the benefits of on-peak production, reduced distribution and transmission, and avoidance of greenhouse gases are not even close to covering the costs.

I think there are a few problems with Borensteins report (pdf):

  • It doesn’t quantify the costs of energy security.
  • It doesn’t address risk premiums associated with uncertainties in oil and gas prices.
  • And it uses the actual time-of-use tariffs for valuing the PV production, which in my opinion understate the value of Distributed Generation for diversity, reliability, and local voltage support (which actually increases the efficiency of other users on the same distribution line.

Nevertheless, I continue to feel that rooftop PV is not viable, though I think there are great applications where some economies of scale can be achieved, such as Rights of Way, or Concentrated PV such as the GreenVolts system.

I recently heard Dr. Richard Swanson, CTO and Founder of SunPower Corp. talk about the history of PV technology, at a Bird Foundation event. He claimed that rooftop PV will be competitive without subsidies when the cost gets to $1.50 per watt, in three to four years.

I was curious to see whether PV would be viable for me, so I surfed over the to SunPower Solar Calculator that Swanson mentioned. We’re already pretty efficient, and time-of-use net metering isn’t advantageous, since we work from home, and would not have a lot of excess power to sell at on-peak rates. Nevertheless, I was surprised to see how bad an investment rooftop PV is for us. Take a look at this chart, and you’ll see that this system doesn’t even break-even for 30 years; just the debt service is a killer!
So I guess I’m with Professor Borenstein on this.

SunPower Calculator results