Solar: A look at how the sun affects the land

Like the gunslinger of old whose card read “Have gun. Will travel.” our current attitude towards building solar facilities can be largely summed up with the card, “Have land. Build facility.”  There is no doubt we have made tremendous strides in generating solar energy. There is also no doubt that we have given little to no thought as to how we have gone about expanding our generation of solar energy.

The time has come to change that mentality. A new study by Carnegie Science has uncovered an irony of being “green”. Almost 30% of all utility-scale solar installations are on lands that once were croplands and pastures. The farmers have gone from harvesting food to “harvesting” the sun. The drought of southern California, it seems, has given us a perfect example of the law of unintended consequences.

To be clear, the study is not about trading food for energy; it is a study on the impact of solar energy on land use. It is the first such study. It’s an obvious study to be done when you read it, but this one is the first to raise the issue of the way we are using the land to capture solar and then to challenge us to get innovative about our land use.

The study looked at two solar technologies, photovoltaic (PV) and concentrating solar power (CSP). The first is the traditional solar panels which uses the sun to generate electricity while the second uses mirrors to focus the sunlight on a single point to heat water into steam to power generators.  The study was published in the Proceedings of the National Academy of Sciences and it assessed the impact of 161 existing, planned or under construction utility-scale solar energy facilities in California.

What researchers for Carnegie found are that 28% of such plants are in croplands and pastures, while 19% are in remote areas far from transmission lines resulting in adverse economic, energetic and environmental consequences.  It is helpful to remember here that electricity does not travel well: the longer the distance travelled the greater the energy loss.

Rebecca Hernandez, a co-author of the study, says their work illustrates the importance of realizing the impact of solar on the land, “..we see that big solar is competing for space with natural areas. Knowing this is vital for understand and creating predictions of a rapidly changing global energy landscape.”

All of which might sound like academic gobbledygook until you read that if we, as a country, want to reduce greenhouse emissions by 80% from the benchmark of 1990 emissions it will require a solar farm roughly the size of South Carolina.  That’s a lot of land.

The simple point of the study is that we have to get innovative not only with our energy but with our land use. Fortunately, we already have begun that innovation. Hernandez points to farmers who are adapting solar to their farming and it goes way beyond putting some solar cells on their barns. They are integrating the panels into their fields, some even mounting the panels above their crops to provide shade and allow harvesting underneath.  This innovative use actually has a name now, Agro-voltaic. Float-voltaic is the study of solar panels on bodies of water, such as irrigation canals. This application helps cool the panels and reduce water evaporation. (not only is use getting innovative, so is the language)

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http://www.forbes.com/sites/billtucker/2015/10/23/solar-a-look-at-how-the-sun-affects-the-land/?ss=energy