STUDY: Rooftop Solar and EVs Cut Water Usage and Pollution

Solar panels and electric vehicles (EVs) are two prime examples of technologies that can help people minimize their environmental footprint, without sacrificing comfort or having to radically change their daily behavior. But the question still remains: how much of an environmental benefit do these technologies actually produce? And, are there actions that owners of these technologies can take to minimize their pollution footprint even more?

A paper recently published in Energy Economics attempts to answer these two questions for households in Austin, Texas. These homes are part of Pecan Street Inc., a living smart-grid laboratory with the largest customer energy-use database on the planet. Using detailed household-level data from 2013-2015, researchers were able to track solar panel performance and EV use and charging patterns, and match these actions to two important environmental impacts: water use and greenhouse gas (GHG) emissions.

They found that, in Texas, residential solar panels use less water and pollute the air less than does using the central-grid power (based on its electricity sources during those years). In addition, they found that driving an EV instead of a gasoline vehicle generally reduces the household’s water and emission footprint, though EVs charge from the grid.

A few key findings:

  • Wind and solar PV need virtually no water to create power, and they do not emit GHGs or other pollutants in the process.
  • Because solar panels consume no water and emit no pollution, installing a solar panel allows a household to reduce both the water use and air pollution associated with grid electricity.
  • Importantly, they found that a household can improve its environmental footprint even further by facing its solar panels south, capturing more sun throughout the day.
  • EVs always reduce GHG emissions, on net, regardless of the alternative vehicle. Although the benefits do vary largely with the efficiency of the alternative vehicle, they would always increase the cleaner the grid becomes.

Reposted from Breaking Energy

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