Yes, some greenhouse gases slip out when technology to capture renewable energy is being manufactured. But over their operating lifetimes, emissions from solar, wind, and other renewable energy facilities are a fraction of those from the equivalent generation from fossil fuels.
International researchers calculated the life cycle greenhouse gas emissions for different energy systems, presenting their findings in an article published last month in the journal Nature Energy.
The group projected life cycle emissions 78 to 110 grams of CO2 equivalent (CO2e) per kWh of electricity produced from fossil fuels, even in plants equipped with carbon capture and sequestration. That compared to just 3.5 to 12 grams for wind and solar power by 2050.
Nuclear stations generated similarly low-carbon power. Life cycle emissions from hydropower and bioenergy, while “highly uncertain,” were likely to be at the high end of the fossils’ range—in the area of 100 grams of CO2 equivalent per kWh of electricity produced.
The investigators, led by Michaja Pehl of the Potsdam Institute of Climate Impact Research, found that substantial upscaling of non-hydro renewable energy extraction still produced small cumulative greenhouse gas emissions compared to continued use of fossil fuels.
“This finding refutes an argument made by some critics that even low-carbon sources of energy have so-called ‘hidden’ greenhouse gas emissions—for instance, the energy needed to produce solar panels—that would negate their climate benefits,” asserts the blog belonging to the Yale School of Forestry and Environmental Studies, one of whose scientists, Edgar Hertwich, participated in the research.
“Often, people object to low-carbon energy systems, pointing to the energy needed to produce all the solar cells and wind power plants,” Hertwich remarks in the post. “But due to technological innovation, less and less energy will be needed to produce wind turbines and solar photovoltaic systems.”