New research led by the University of Michigan and published in Nature Energy finds that using electric vehicle batteries to power homes—vehicle-to-home charging, or V2H—can both save owners money and reduce greenhouse gas emissions from the power grid and buildings. Supported by the Ford–University of Michigan Alliance Program, the study models a representative mid-sized SUV and maps impacts across the contiguous United States.
The authors estimate that V2H could lower charging costs by roughly 40% to 90% over a vehicle lifetime, equal to about $2,400 to $5,600 in savings. They also find lifecycle household electricity emissions could fall by about 70% to 250%, or roughly 24 to 57 tons of CO2 over a vehicle lifetime. The study gives concrete comparisons: these cuts equal driving a small gas SUV for about 80,000 to 190,000 miles, or about 80 to 190 one-way flights between New York and Los Angeles. Reductions can exceed 100% when V2H more than offsets emissions from the extra electricity used to drive the car.
The team divided the contiguous US into 432 regions based on climate and grid conditions to show where benefits vary. V2H produced net greenhouse gas reductions in regions covering about 60% of the US population, and in parts of Texas and California cost savings can even pay for the electricity used for driving. The researchers warn that control technology to maximise V2H is still early in the US but is being demonstrated with local utilities. Teams are working on optimisation, battery life and automation so drivers simply park and plug while software manages charging and discharging.
- Coauthors include Parth Vaishnav, Jiahui Chen and Hyung Chul Kim.
- The team also published a policy brief and cites University of Michigan as the source.
Difficult words
- vehicle-to-home charging — using a car battery to supply home electricity
- greenhouse gas emissions — gases released that warm the Earth's atmosphere
- lifecycle — whole period from production to disposal or end
- optimisation — process of making something as effective as possible
- discharge — release stored energy from a batterydischarging
- contiguous — connected and touching in the same area
- offset — balance or cancel the effect of somethingoffsets
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- What factors might explain why V2H produces benefits in some regions but not others? Give two reasons based on the article.
- How could automation and optimisation of V2H change drivers' daily behaviour or routines? Give examples.
- The study compares emission cuts to miles driven or flights avoided. Do you find these comparisons helpful? Why or why not?
