Solar panels have paid their energy debt (or are very close to it)

Solar power has produced more energy than it took to make and install the systems, a new study has found.

Researchers in the Netherlands calculated the global solar panel – or photovoltaic – industry will also break even within the next couple of years when it comes to greenhouse gases too.

“Over the whole life-cycle of a [photovoltaic] system, it pays back the energy invested and greenhouse gas emissions released during its production multiple times,” Atse Louwen from Utrecht University and colleagues write in Nature Communications.

Since 1975, installed photovoltaic capacity increased from less than one megawatt to almost 180 gigawatts in 2014. At the same time, the financial cost dropped from almost UD$100 per watt to around 65c per watt.

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But even though the industry is supported by governments across many countries, some critics have questioned the energy consumption and greenhouse gas emissions required to produce the panels and make the switch from other energy sources.

To address these concerns, Louwen and colleagues analysed data from 40 studies of solar panel systems conducted between 1976 and 2014 and modelled these alongside global average installation rates.

As solar panel use increased over the decades, the data showed a reduction in financial cost, greenhouse gas emissions and energy use in the production and delivery of the technology. 

For every doubling of solar panel usage, they found, energy used during production decreased by up to 13%, while the industry’s greenhouse gas footprint dropped by up to a quarter.

Admitting that some aspects of their model are debatable, the researchers say a conservative break-even point for energy cost and gas emissions should occur somewhere between 1997 and 2018. 

So, either it’s already happened, or it’s just around the corner – which means the full benefits of the industry are yet to be felt, the researchers write.

“The future development of photovoltaics is very difficult to predict, as every year of development seems to exceed our expectations.”