City-based solar is best source of clean energy, says study

Building solar systems into the infrastructure of cities could be the most efficient way to provide clean energy according to a new study by Stanford University.

Using California as an example, researchers found that solar equipment constructed on and around urban infrastructure would exceed the state’s energy demands by up to five times.

The growth of solar energy is currently limited by the need to find space for equipment without altering the surrounding area, but this new discovery could lead to a solar boom, according to the researchers.

“Integrating solar facilities into the urban and suburban environment causes the least amount of land-cover change and the lowest environmental impact,” explained researcher Rebecca Hernandez.

Land of opportunity

Around 8% of terrestrial surfaces in California have been developed by humans – from cities and buildings to park spaces.

Residential and commercial rooftops present plenty of opportunity for power generation through small- and utility-scale solar power installations. Other compatible opportunities are available in open urban spaces such as parks.

“Because of the value of locating solar power-generating operations near roads and existing transmission lines, our tool identifies potentially compatible sites that are not remote, showing that installations do not necessarily have to be located in deserts,” Hernandez said.

Solar combination

The study said the most efficient method of generation would be a mix of solar PV and solar thermal to take advantage of different landscapes and structures.

Combined, the technologies could generate 21,000 TWh of energy a year in California.

California has targets that require 33% of retail electricity be provided by renewable sources by 2020, and greenhouse-gas emissions to be 80% below 1990 levels by 2050. Likewise the UK Climate Change Act requires the UK to reduce emission by 80% by 2050.

“Our findings have implications for other states and countries with similarly precious environmental resources and infrastructural constraints,” said the research paper.

UK viability

While the UK may not have the sunshine of California, more than 10% of its land is classified as urban – more than enough infrastructure to host solar systems that could power the entire country.

The UK utility-scale solar market is booming, and looks set to pass India and Germany to become the third largest in the world.

Brad Allen

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