Rapid PV Installations Can Temporarily Increase Global Warming

Achievement date: 
2014
Outcome/accomplishment: 

Researchers at the NSF-funded Engineering Research Center (ERC) for Quantum Energy and Sustainable Solar Technologies (QESST), which is headquartered at Arizona State University, have shown that rapid photovoltaic (PV) installations to meet California’s policy targets can temporarily (for 10 to 15 years) increase global warming impacts. These impacts result from the current geographical distribution of PV manufacturers in locations that use carbon-rich sources of energy compared to lower carbon intensity of electricity displaced by the installation of PV panels in California.

Impact/benefits: 

These and other associated findings define pathways to guide PV manufacturers, policy makers, and researchers on reducing the environmental impacts and economic costs of future PV manufacturing and deployment activities. For example, the research indicated that it takes around 12 and 9 years in California and Wyoming, respectively, for global-warming benefits of PV deployment to exceed the up-front global-warming impacts of PV manufacturing (benefits are realized earlier in Wyoming than California because of the higher dependence of coal for electricity in Wyoming).

Explanation/Background: 

The researchers have also shown that the global-warming impacts originating from transitioning to terawatt-scale PV systems at a national and international level can be substantially decreased if the energy intensities of upstream solar-grade silicon production and silicon wastage due to kerf losses (from slicing) are reduced. Further, PV deployments in locations where electricity is currently produced from carbon-intensive sources (i.e., coal) will significantly reduce global-warming impacts over the PV system’s life cycle compared to deployment in lower carbon-intensive electricity regions.