The detractors of the electric batteries they can put the heart at peace. A few weeks ago, a study showed that the electric car is more environmentally friendly and affordable than the one with a combustion engine. Even when its energy comes from traditional sources.
Today a new study shows that exhausted batteries (the subject of the doubts of the last skeptics) can return to new life, with much less waste and pollution.
Solar farms could offer a second life for electric vehicle batteries. A study shows that battery reuse systems could be profitable for both electric vehicle companies and grid-scale solar operations.
The future has arrived. Electric vehicles will rapidly grow in popularity around the world, and soon there will be a wave of used batteries whose performance will no longer be sufficient to ensure reliable acceleration and range.
Skeptics about the electric future of the car are focusing on this particular detail. “And what happens to the batteries, then? Other than an ecological choice! ". Except then rely on the internal combustion engine, a remnant of the oil age, and therefore of the stone.
This new study takes away yet another argument from reactionary temptations. It demonstrates that spent batteries in electric cars can still have a profitable second life as backup storage for grid-scale photovoltaic installations. And they can play this less demanding role for more than a decade after "retirement" from a car.
I study, published in the Applied Energy magazine, was led by six MIT researchers, including Ian Mathews and Tonio Buonassisi, head of the photovoltaic research laboratory.
What the research consisted of
As a model, the researchers examined in detail a hypothetical solar farm connected to an electricity grid. The team studied the economics of different scenarios. Primo, build a 2,5 megawatt solar farm. Second, construction of the same type of solar farm combined with a new lithium-ion battery storage system. Third, building a solar farm also using EV batteries that had dropped below the point where their capacity is considered too weak for use in a vehicle.
The most interesting thing is that a properly managed system of used EV batteries could also be profitable, as long as the value of these batteries drops to less than 60% of their original price.
How are batteries "resurrected"?
The process may seem simple, and it has already been implemented in smaller-scale projects, but expanding it on a network scale isn't that simple, the researchers explain. “There are several technical problems to be addressed. How to put batteries from different machines together so that you know they will perform well and you won't have a much lower battery than the others, which drags down system performance?".
This also makes us understand how the electric car system must grow on a solid basis and taking into account the pluses of the previous experience based on internal combustion engines. Just to say, gasoline is a "standard". Apart from a few differences, today all engines are filled with the same petrol.
Why not create a standard for batteries? Same density, maybe modular, similar dimensions and more. Only in this way will it be ridiculous to swap, or "recycle" the exhausted batteries for other uses.
A recent report from McKinsey Corp. shows that as the demand for backup storage for renewable energy projects grows between now and 2030, second-use EV batteries could potentially meet half of that demand. Some electric vehicle companies, including Rivian, are already designing their batteries specifically to make this "transition to new life" as easy as possible.
Exhausted batteries: how long will they last?
Another unknown factor is how long the batteries can continue to function effectively in this second application. The study took a conservative assumption that batteries would be withdrawn from service after decreasing to 70% of their nominal capacity, from their initial 80% (the point at which they were withdrawn from electric vehicle use). But it could be, says Mathews, that continuing to operate down to 60% capacity or even below could prove safe and useful.
“Many states are really starting to see the benefits that storage can offer,” says Mathews.
