Jun 15 2017
Stored energy from electric vehicles (EVs) can be applied to power large buildings – opening up new possibilities for the future of smart, renewable energy - as a result of innovative battery study from WMG at the University of Warwick.
As a result of an innovative research from WMG, University of Warwick, energy stored in electric vehicles can be used to power large buildings. Researchers discovered that by intelligently handling vehicle-to-grid technology, energy from idle vehicle batteries can be transferred back into the grid – and this would enhance vehicle battery life by about 10%. ‘Smart grid’ developed, which calculates how much energy can be absorbed from electric vehicles without negatively affecting batteries, and really enhances longevity and performance. Vehicle-to-grid technology was formerly thought to cause degradation of battery life – but this research reveals that it could keep vehicle batteries healthier for longer
Dr Kotub Uddin, WMG (Credit: WMG, University of Warwick)
Dr Kotub Uddin, with colleagues from WMG’s Energy and Electrical Systems group and Jaguar Land Rover, has shown that vehicle-to-grid (V2G) technology can be intelligently used to absorb enough energy from idle EV batteries to be pumped into the grid and power buildings – without degrading the batteries.
This new research into the possibilities of V2G demonstrates that it could actually boost vehicle battery life by about 10% over a year.
For two years, Dr Uddin’s team examined some of the world’s highly advanced lithium ion batteries used in commercially available EVs - and built one of the most accurate battery degradation models present in the public domain - to calculate battery capacity and power fade over time, under a range of aging acceleration factors - including temperature, current, state of charge and depth of discharge.
Using this confirmed degradation model, Dr Uddin formulated a ‘smart grid’ algorithm, which intelligently analyzes how much energy a vehicle needs to perform daily journeys, and – importantly – how much energy can be removed from its battery without negatively impacting it, or even optimizing its longevity.
The Researchers applied their ‘smart grid’ algorithm to check if they could power WMG’s International Digital Laboratory – a large, busy building which has a 100-seater auditorium, two electrical laboratories, meeting rooms, teaching laboratories and houses nearly 360 staff – with energy from EVs located on the University of Warwick campus.
They analyzed the number of EVs parked on the campus (about 2.1% of cars, in line with the UK market share of EVs) that could spare the energy to power this building. In doing so, capacity fade in participant EV batteries would be decreased by up to 9.1%, and power fade by up to 12.1% over a year.
It has been formerly thought that taking energy from EVs with V2G technology causes their lithium ion batteries to degrade more quickly.
Dr Uddin’s team (together with collaborators from Jaguar Land Rover) has proved, however, that battery degradation is more multifaceted - and this complexity, in operation, can be utilized to increase a battery’s lifetime.
Given that battery degradation relies upon capacity throughput, calendar age, state of charge, current, temperature and depth of discharge, V2G is an effective tool that can be used to enhance a battery’s conditions such that degradation is curtailed. Hence, extracting excess energy from an idle EV to power the grid really keeps the battery healthier for longer.
These findings reinforce the attractiveness of vehicle-to-grid technologies to automotive Original Equipment Manufacturers: 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 results are also appealing to policy makers interested in grid decarbonisation.
Dr Kotub Uddin, WMG, Warwick University
The study, ‘On the possibility of extending the lifetime of lithium-ion batteries through optimal V2G facilitated by an integrated vehicle and smart-grid system’ has been published in Energy.
The study was funded by the Engineering and Physical Sciences Research Council and the WMG centre High Value Manufacturing Catapult, in partnership with Jaguar Land Rover.