Automotive

EV battery life extended by feeding energy back into the grid

EV battery life extended by fe...
EV batteries could have their life extended by feeding some of their energy back into the grid
EV batteries could have their life extended by feeding some of their energy back into the grid
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The set-up by the research team to test the long term storage capacity of EV batteries
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The set-up by the research team to test the long term storage capacity of EV batteries
EV batteries could have their life extended by feeding some of their energy back into the grid
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EV batteries could have their life extended by feeding some of their energy back into the grid

Researchers at the University of Warwick have demonstrated a new "smart grid" system whereby energy from idle electric vehicle (EV) batteries could by pumped back into the grid to power large buildings, while still leaving enough power to complete the vehicle's daily journeys. The study also demonstrated that this approach could actually increase the overall longevity of the vehicle's lithium-ion battery.

This new research paves the way for vehicle-to-grid (V2G) technology that cleverly uses parked EVs to support localized power grids. The team developed a "smart grid" algorithm that can calculate how much energy an individual vehicle requires for its daily journey and how much energy can be safely taken from it and fed back into the grid.

The initial model calculated that a large building at the University of Warwick could be powered by the current number of EVs already parked on the campus. On a daily commute that consumes between 21 and 38 percent of a battery's capacity, the simulation estimated that feeding 40 and 48 percent of the battery's charge back into the grid could cut the inevitable capacity fade and power fade of the battery by around 6 and 3 percent, respectively, over a three-month period.

So not only did extracting this power not damage the batteries, but it actually improved their overall longevity. Analyzing some of the more advanced, commercially available EV batteries, the study claims that battery pack capacity fade can be reduced by up to 9 percent, and power fade by up to 12 percent through this V2G process.

The set-up by the research team to test the long term storage capacity of EV batteries
The set-up by the research team to test the long term storage capacity of EV batteries

"These findings reinforce the attractiveness of vehicle-to-grid technologies to automotive Original Equipment Manufacturers," says Dr Kotub Uddin, one of the lead authors of the research. "Not only is vehicle-to-grid an effective solution for grid support – and subsequently a tidy revenue stream – but we have shown that there is a real possibility of extending the lifetime of traction batteries in tandem."

The study looks forward to a win-win situation for electric vehicle owners in the future, where car batteries could have their life extended and offer a small revenue stream to the owners by supplying electricity to local grids.

The research was published in the journal Energy.

Source: University of Warwick

6 comments
Alien
I find it hard to imagine that recharging the battery at home and then recovering some credit for discharging some electricity into another grid point can offer a 'break even' deal ...so the vehicle owners will still be paying for the gain in battery life. Surely the utilities are not going to 'buy it back' at the same price that they sell it for? Perhaps it might be viable to use the battery discharge at home also but once again it will come back to the grid's differentials between sale and purchase. Aren't there problems already with utilities in California reducing their purchasing prices for solar generated electricty that is fed back into their grid?
Mik-Fielding
Whilst the extra cycling of the batteries may give an advantage to the battery life, the energy aspects do not add up. First of all, there are losses incurred in the charging process, both via the charging device and in the actual battery charging itself, where there is less than 100% transfer of energy. Secondly, there are the inefficiencies of taking the energy from the battery and converting to an AC mains voltage, synchronized with the local grid. This means that the cost of this stored electricity will be greater than from the AC grid, so it fails badly on this point and doesn't make economic sense. What may make slightly more sense is to charge the vehicles at the place of work and use the stored energy to power homes at night and the weekends. Nighttime is when solar power systems need the extra storage capacity, not during the day when people are at work, so if this concept was to be used anywhere, then it is at home, not the place of work ...
ChairmanLMAO
the savings comes from no electricity carrier or rider charges. the building owner could probably power the whole building with charged cars. the electric company won't like it because they get most of the electricity back usually. in this scenario most of the electricity could be captured.
Stephen N Russell
For EV Grids worldwide, replicate process, awesome.
snave
My power, recovered into someone elses local grid? Not happening, unless there's a profit to it that's greater than me taking that energy home and using it to power my house - which means payback at greater-than-domestic rates, sufficient to pay for the battery storage device. In whose world is that going to happen? Scientists, eh? And just how clever is the AI to know I'm not going into the next town with friends after work?
swaan
The study expects that the car isn't charged and discharged in an optimal manner in the first place - something that can be tweaked with a software update.