Timing Is Everything When It Comes to Battery Charging

Adding an electrical storage battery can save electrical costs. But unless regulations change, they may not help reduce greenhouse gas emissions.

One way for homeowners to reduce their monthly power bill is to install an electrical storage battery. By charging the battery when electrical rates are low, and then using the stored electricity when rates are highest, studies have shown that it is possible to save as much as 30% on an electrical bill. Unless fundamental policy and regulatory reforms are undertaken, however, adding a storage battery could actually result in increased carbon dioxide emissions, according to a recent study reported in a University of California in San Diego news release.

Tesla Powerwall

Home-based electrical energy storage systems, like the Tesla Powerwall, can help reduce power bills. But cutting greenhouse gas emissions will require regulatory and policy reforms. (Image source: Tesla)

The problem comes from the fact that the batteries draw their energy from the grid when it is the cheapest. The cheapest sources of electricity are often those, like coal-fired plants, that produce the most greenhouse gas emissions.

According to the UCSD study, for the battery systems to actually reduce greenhouse gases, utilities would need to change their tariff structures substantially—accounting for emissions from different power sources. They would need to make energy cheaper for consumers when the grid is generating low-carbon electricity. The research, which was done by UC San Diego’s School of Global Policy and Strategy and Jacobs School of Engineering, modeled how residential energy storage systems would operate in the real world—deployed across a wide range of regions, utilities, and battery operation modes.

“We sought to answer: What if consumers on their own or in response to policy pressure adopt these systems? Would greenhouse gas emissions from the electric power system go down, and at what economic cost?” said lead author Oytun Babacan, a postdoctoral scholar at the School of Global Policy and Strategy, in the UCSD news release.

“Absent tariff reform, policymakers could still encourage environmentally beneficial operation of the devices by ensuring that system developers and equipment vendors favor clean energy use by tracking and adjusting to variations in marginal emissions across the bulk grid,” the authors noted in their study. Systems do not track or encourage such cost-effective emissions control right now, but the study authors indicated that such changes would improve the advantages of home-based electrical storage batteries.

The addition of solar panels to add energy to electrical home storage batteries also changes the greenhouse gas emission picture in favor of home storage systems.

“There is an enormous upside to these systems in terms of flexibility and saving households money,” the authors said. “While the increase in home batteries deployment is underway, we need to work on multiple fronts to ensure that their adoption is carbon minded,” they added.

Senior Editor Kevin Clemens has been writing about energy, automotive, and transportation topics for more than 30 years. He has masters degrees in Materials Engineering and Environmental Education and a doctorate degree in Mechanical Engineering, specializing in aerodynamics. He has set several world land speed records on electric motorcycles that he built in his workshop.

BDesignCon 2019 engineering educationy Engineers, For Engineers. Join our in-depth conference program with over 100 technical paper sessions, panels, and tutorials spanning 15 tracks. Learn more: DesignCon. Jan. 29-31, 2019, in Santa Clara, CA. Register to attend. Hosted by Design News’ parent company, UBM.

Comments (4)

Please log in or to post comments.
  • Oldest First
  • Newest First
Loading Comments...