The case for renewables is clear: Evidence shows that, even when including production, maintenance and tear-down costs, wind and solar energy are still significantly greener, in terms of greenhouse gas emissions (GHG), compared to fossil fuels. This is why news about growing solar and wind capacity in the United States and around the world is an unequivocal positive as we shift to a clean energy economy.
Of course that doesn't mean there aren't areas in which wind and solar could improve and become even more green. But to make clean energy greener, we need good, reliable data. That is what a new report published in the journal Energy Policy, entitled Assessing the Lifecycle Greenhouse Gas Emissions from Solar PV and Wind Energy: A Critical Meta-Survey, seeks to provide to renewable manufacturers and planners.
“[The report authors] examined more than 153 studies on the life-cycle CO2 emissions of a range of wind and solar photovoltaic (PV) technologies, and selected 41 for deeper analysis, allowing the scholars to better understand the emissions of current technologies as well as pinpoint where emissions occur and under what circumstances, and thus how they might be reduced. All the studies chosen for inclusion were peer-reviewed and more than 70 percent were published within the last five years,” the report reads.
Researchers also examined the various stages of a technology's lifespan, and found that the phase that could be most greened is what the authors called the “material cultivation and fabrication stage,” a fancy way of saying building and setting up. This alone was responsible for 71 percent of both solar and wind GHG emissions. A focused effort to bring this number down could really reduce the smaller, but significant, carbon footprint of renewable energy technologies.
Another key – building energy systems that last. The longer the lifespan of a wind or solar installation, the lower its GHG emissions. Thus, a greater up-front cost to build a more durable system could pay off huge carbon dividends in the long term.
“By spotlighting the lifecycle stages and physical characteristics of these technologies that are most responsible for emissions, improvements can be made to lower their carbon footprint,” the report concludes.
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