That solar power and electric vehicles (EVs) are better for the environment than fossil fuel and gas-powered vehicles should be a given but new research from the Environmental Defense Fund (EDF) on Austin’s Pecan Street Inc. project shows just how dramatic it can be.
The organization’s research showed that solar power reduced a home’s greenhouse gas emissions and water use by a combined 75 percent, the study found. Compared to conventional vehicles, EVs can also avoid up to 70 percent of CO2 emissions and 60 percent of water consumption, depending on the type and efficiency of the vehicle they’re replacing.
In “The environmental impacts of green technologies in TX,” which was published in Energy Economics and a blog post at EDF Beia Spiller, Senior Economist at EDF, explained that “Our paper confirms that, in Texas, residential solar panels uses less water and pollutes the air less than using the central-grid power (based on its electricity sources during those years).”
“We find that a household can improve its environmental footprint even further by facing its solar panels south, capturing more sun throughout the day,” Spiller explained. But Pecan Street offers specific incentives to homeowners that install solar panels on the west side of a home to maximize production during peak use hours. “A better understanding of hourly energy usage and emissions can inform electric system policies and pricing that lead to a reduction in total costs, including those related to the environment,” she said.
“Driving an EV instead of a gasoline vehicle generally reduces the household’s water and emission footprint, even though EVs charge from the grid. Moreover, our analysis demonstrates how carefully examining energy-use data can help us make sure we’re maximizing clean energy’s benefits,” Spiller said.
Pecan Street Inc. is a kind of living lab that monitors and measures the energy use and behavior of more than 1,100 Austin-area participants created through a partnership between EDF and the University of Texas in 2008. “Using detailed household-level data from 2013-2015, we 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,” Spiller said.
The organization calculated the reduction in household water use including the water used for electric generation from a natural gas or coal plant, which uses large quantities of water in processing and cooling. It also takes about about four gallons of water to produce one gallon of gasoline, according to Spiller.
The findings for EVs were more variable because of the type of vehicle they replaced. “To be able to quantify the environmental benefits of EVs, we needed to think about what vehicle the household would have driven had it not purchased an EV,” Spiller said.
If a family replaces a gas-guzzler with an EV, Spiller said, it’s beneficial. But if they replace a hybrid with an EV in Texas it might not be as beneficial since the power used to charge the EV still comes from the largely fossil-fuel powered grid in the state, which could increase the household’s overall emissions compared to a hybrid.
“Solar panels and electric vehicles will help pave the way to a cleaner future, but we must dig into the details to ensure we maximize the environmental benefits. The more data we have and examine, the better that decision-makers can design energy programs and incentives to improve our environmental footprint,” Spiller said.Tweet