Beyond Comprehension

Sciencenews reports that a new study Emissions from Photovoltaic Life Cycles shows Solar power produces about one-tenth as much carbon dioxide and other harmful emissions as does conventional power generation.

Making the solar cells does use materials and energy—mainly from conventional power sources such as coal-fired power plants, which produce emissions. Industrial techniques for making glass and other materials in solar panels also produce gases such as carbon dioxide.

In the 1970s, manufacturing a solar cell required about as much energy as the cell could produce over its 20-year lifetime, so using solar power provided little if any energy gain. Also, as recently as 10 years ago, total emissions from solar cells were about twice what the new study shows. Solar power has been criticized in the past\" for requiring too much energy to produce, but with the current technology, it is no longer true.

Much of the improvement is from reducing energy and materials for making solar cells. Compared to those made in the 1970s, modern panels contain about one-third as much purified silicon, which is energy intensive to make. And thin-film solar cells trim back even further by depositing silicon or other materials in layers only a few thousandths of a millimeter thick.

The study also concludes that the improvements in energy efficiency allows shorter "energy pay back" of only 1 to 3 years.

Improvements in manufacturing efficiency could reduce emissions from solar power by another 50 percent within 5 to 7 years.