Wednesday, September 5, 2012

Argument Over the Value of Solar Focuses on Spain

News of an upcoming study evaluating the Energy Return on Investment (EROI) of solar PV includes an interesting evaluation of methods with higher EROI.
I get the message that projects with low EROI are being built because the costs of the fossil fuels invested is still cheap - so the cheap solar PV we hear promised will bump fossil fuels is actually the PV that utilizes fossil fuels the most.
That seems to be why it's the cheapest.

"Coauthored by ecologist Charles A.S. Hall and Spanish telecom and solar systems engineer Pedro A. Prieto, the book is a case study of Spain's utility-scale installations of photovoltaics. It will be, the authors claim, the first comprehensive analysis of large-scale PV based on data rather than models. Hall—a professor at the State University of New York College of Environmental Science and Forestry, in Syracuse—formalized the concept of EROI more than 40 years ago, as the energy yielded by an energy-gathering activity divided by the energy invested in that activity.

While mum on their EROI numbers, Hall and Prieto say the book will demonstrate that building and operating PV requires considerably more energy than its promoters claim. And, they add, fossil fuels provide the bulk of the energy investment. "The conclusion is that solar PV systems are very much underpinned by a fossil fuel society," says Prieto. "
Prieto cites two dozen energy inputs left out of many life-cycle analyses of photovoltaic systems. He witnessed these inputs directly while building one of Spain's earliest utility-scale solar facilities—a 1-megawatt plant in Extremadura that began operating in 2006—and while supporting subsequent PV installations. The factors include construction of roads, water pipes, and transmission lines to serve the often-remote solar sites, and even international flights to get on-site help from specialist engineers. 

All told, says Prieto, the result could be an EROI figure even lower than the already controversial EROI of 6.8 that Hall previously cited for PV
Read the full article at IEEE Spectrum:

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