Solar panels are manufactured using similar methods as the manufacture of computer chips and glass panels.

How much greenhouse gas does solar panel manufacture emit? The answer depends on the type of solar panel, says Vasilis Fthenakis, head of the Photovoltaic Environmental Research Center at Brookhaven National Lab. Fthenakis and has conducted extensive research on the environmental impacts of solar and compared it with other technologies like fossil fuel to get a better idea of the big picture. “There’s nothing that’s completely risk-free,” says Fthenakis. “But photovoltaic compares very favorably with all other technologies.”

With today’s technology, the energy required to manufacture a solar panel is roughly equal to the energy that panel will produce in less than 2 years of operation. Given a 30-year panel life, a solar panel produces clean energy for over 28 years after its “energy debt” has been repaid.