The Hockey Schtick blog specializes in summarizing scientific papers that have a sceptical leaning. A couple of days ago it posted about the World’s largest solar energy plant applying for a $539million federal grant to help pay off a $1.5 billion federal loan. The Ivanpah solar electric generating plant is owned by Google and renewable energy giant NRG. Google can certainly afford to bear these loses. At the end of 2013 its accounts state that it had Cash, Cash Equivalents & Marketable Securities of $58,717million, $10,000million than the year before.

Technologically the Ivanpah plant sounds impressive. Problem is that in it’s first year of operation it produced one quarter of the projected electricity. As a minor consequence, it was projected to scorch 1,000 birds a year. Instead it is 28,000 in the first year. A three minute summary is at Fox News.

But even at the planning stage there was either no proper business plan presented, or at least no proper scrutiny like a bank would do when making a loan. 1065,000 MWh annually from a 392 MW nameplate is a planned output of 31% of capacity. Even accepting that figure, a $2bn investment with a 20 year payback (zero discount rate) is still nearly $100 MWh. A 10 year payback is much more reasonable. Add maintenance and operating costs easily gets to $200 MWh. A small utility company in Wisconsin buys in extra electricity for $30 MWh. So the planned cost was 6-7 times the wholesale price of electricity.

Maybe this was justified in saving the planet?

The AR4 synthesis report of 2007* said that peer-reviewed estimates of the social costs of carbon from averaged on 2005 $12 per tonne of CO₂, but the range from 100 estimates is large (-$3 to $95/tCO₂). If we take the bold assumption that the theoretic output of this plant would entirely replace the electricity from a typical coal-fired power station producing 900kg of CO2 per MWh, then the saving is $190t/CO2, or double the very top-end 2005 estimate, or 15 times the average estimate. For some reason, the Social Cost of Carbon is missing from the

Suppose the US was “really serious” about doing its bit to save the planet and tried to cut its CO2 emissions by 80%. In round figures, in 2013 that was 5 billion tonnes of CO2 equivalent (source CDIAC). Using similar schemes, it would cost $760bn a year or 5% of 2013 GDP of $16.8trn. Remember, that is if similar schemes are successful. The Ivanpah solar plant does not look like a success.

* For some reason, the Social Cost of Carbon is missing from the AR5 Synthesis Report published on November 1^st. I would guess the reason that it has fallen out of favour is that the marginal abatement costs are much larger than the highest estimates, and the cost of doing nothing per tonne of CO2 are about zero.

Kevin Marshall