Hooking EVs to Grid Could Power Buildings, Improve Vehicle Battery Life
Hooking Electric Cars to Grid Could Power Buildings, Improve Vehicle Battery Life
Mon, 06/19/2017 - 3:09pm 6 Comments
by Seth Augenstein - Senior Science Writer - @SethAugenstein
The traditional thinking on electric cars: they are hooked up to the power grid to charge, continually replenishing their advanced batteries.
But reversing that flow of energy from vehicles back into the grid could not only power large buildings – it could even improve the cars’ battery life, contends a new study in the journal Energy.
Taking excess energy from an idle electric vehicle actually improves the battery life, based on an algorithm developed by scientists at the University of Warwick.
“Not only is vehicle-to-grid and 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,” said Kotub Uddin, the leader of the team, which included engineers from Jaguar Land Rover.
The complex factors that weaken and degrade advanced lithium ion batteries ...
https://www.laboratoryequipment.com/news/2017/06/hooking-electric-cars-grid-could-power-buildings-improve-vehicle-battery-life
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Study was Open Access funded by Engineering and Physical Sciences Research Council
On the possibility of extending the lifetime of lithium-ion batteries through optimal V2G facilitated by an integrated vehicle and smart-grid system
Kotub Uddina, , , Tim Jacksona, Widanalage D. Widanagea, Gael Chouchelamaneb, Paul A. Jenningsa, James Marcoa
https://doi.org/10.1016/j.energy.2017.04.116
Under a Creative Commons license
Open Access
Highlights
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Long term ageing data collected for battery spanning wide range of conditions.
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Battery degradation model developed and validated using 6 diverse usage cycles.
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Smart-grid shown to extend the life of battery beyond no V2G case.
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Case study shows reduction in capacity fade by 9.1% and power fade by 12.1%.
Abstract
Renewable energies are a key pillar of power sector decarbonisation. Due to the variability and uncertainty they add however, there is an increased need for energy storage. This adds additional infrastructure costs to a degree that is unviable: for an optimal case of 15 GW of storage by 2030, the cost of storage is circa: £1000/kW. A promising solution to this problem is to use the batteries contained within electric vehicles (EVs) equipped with bi-directional charging systems to facilitate ancillary services such as frequency regulation and load balancing through vehicle to grid (V2G) technologies. Some authors have however dismissed V2G as economically unviable claiming the cost of battery degradation is larger than arbitrage. To thoroughly address the viability of V2G technologies, in this work we develop a comprehensive battery degradation model based on long-term ageing data collected from more than fifty long-term degradation experiments on commercial C6/LiNiCoAlO2 batteries. The comprehensive model accounts for all established modes of degradation including calendar age, capacity throughput, temperature, state of charge, depth of discharge and current rate. The model is validated using six operationally diverse real-world usage cycles and shows an average maximum transient error of 4.6% in capacity loss estimates and 5.1% in resistance rise estimates for over a year of cycling. This validated, comprehensive battery ageing model has been integrated into a smart grid algorithm that is designed to minimise battery degradation. We show that an EV connected to this smart-grid system can accommodate the demand of the power network with an increased share of clean renewable energy, but more profoundly that the smart grid is able to extend the life of the EV battery beyond the case in which there is no V2G. Extensive simulation results indicate that if a daily drive cycle consumes between 21% and 38% state of charge, then discharging 40%–8% of the batteries state of charge to the grid can reduce capacity fade by approximately 6% and power fade by 3% over a three month period. The smart-grid optimisation was used to investigate a case study of the electricity demand for a representative University office building. Results suggest that the smart-grid formulation is able to reduce the EVs' battery pack capacity fade by up to 9.1% and power fade by up to 12.1%.
http://www.sciencedirect.com/science/article/pii/S0360544217306825
