An MIT study shows how used battery reuse projects could bring economic benefits to both automakers and solar farms.
Reusing used electric vehicle batteries in large photovoltaic systems is the most convenient option.
The progressive rise of electric vehicles around the world will bring a wave of used batteries as a consequence of their use.
A huge number of storage devices whose performance is no longer sufficient to guarantee reliable autonomy for vehicles. Despite this, they still have a lot of life and recycling may not be the best option. Proof of this is a new MIT study today that the recovery option could play an important role in network storage for more than a decade.
The research, published in the journal Applied Energy, evaluated the potential of used electric car batteries in a hypothetical photovoltaic system connected to California’s electrical grid. In detail, scientists have developed 3 different economic scenarios: the construction of a 2.5 MW solar power plant; the construction of the same plant but integrating a system of new lithium batteries; the construction of the plant integrating recovered batteries, with a capacity of 80% compared to the original.
The result? A system based on used batteries could be a good investment, as long as it costs less than 60% of its original price.
The work may seem simple, but modeling the study on a utility scale is not. ” There are many technical problems ,” explains researcher Ian Mathews. “ How do we select car batteries to make sure they are good enough to be reused? How do we put them together when they come from different cars to make sure they work well? “
Many questions are purely economic. “ Are we sure these batteries are still worth enough to justify the cost of removing them from cars, storing them, checking them and reinstalling them for a new application? Or how long can they usefully function in their second life?
The new research has managed to answer all these questions.
The team used a semi-empirical battery degradation model, using measured data, to predict capacity loss under various operating conditions. He found that lithium batteries could achieve their maximum life and value by operating in relatively “smooth” charge and discharge cycles: never more than 65% of full charge or less than 15%.
Obviously, the real economics of a project can vary greatly depending on specific factors, such as local regulations. However, the California case study wants to be the first great example to consider. ” Many states are beginning to really understand the benefits that energy storage can offer, ” says Mathews. ” And it just shows that they should have a bond that somehow incorporates used batteries into their regulations .”
More information: www.sciencedirect.com – news.mit.edu