The costs (battery wear-and-tear, replacement, etc) associated with the possible use of electric vehicles as energy storage participants in the wider grid were recently analyzed by the people over at Plug In America, giving us some of our first insights into the possible specifics of such a program.
Such a program would of course allow for a fairly cheap distributed energy storage solution (in some cases anyways), thereby functioning as an alternative to grid-scale energy storage projects, or on-demand fossil fuel generators. Hence the interest.
The new findings are the result of the analysis of data gathered via the Plug In America EV Battery studies. Here are some of the highlights (concerning the costs of battery wear for electric vehicle owners that would participate):
For each vehicle, we consider battery pack replacement at either 70% or 80% of original capacity to figure out a per-kWh battery pack amortization cost. The results are shown in the chart below. As you can see from the chart (below), the LEAF and Model S suggest a battery amortization cost between $0.19 and $0.40 per kWh.
As batteries continue to drop in price, we expect these numbers will decrease, but this analysis suggests at least a starting point for considering the cost to owners for participating in a V2G program, and presumably owners will need to be compensated above their amortization cost to justify the inconvenience of early battery pack replacement.
EV owners may be wondering how this relates to driving. Letting the utility cycle one kWh out and back into your car is about the same, in terms of battery wear, as driving it between 3 and 4 miles, depending on the model and how you drive. We can use the EPA ratings to calculate how many miles can be driven for each kWh. When combined with the above data, we can see the the cost in battery wear associated with each mile driven. (Note that this is just a measure of the cost of using the battery, not considering any cost of purchasing the electricity to charge the battery or tire wear, etc.)
So a LEAF owner who plans to drive it forever, just replacing the battery pack as needed, should budget between 5 and 8 cents per mile for battery pack replacements. A similarly minded Model S owner should budget between 6 and 11.5 cents per mile.
How does this compare to a gas car? Edmunds.com says that, on average, a new $30,000 car loses $17,804 in value over 5 years and 75,000 miles of driving. That’s 23.7 cents per mile. For a $70,000 car, it’s $43,953 or 58 cents per mile. So, battery amortization cost is pretty small compared to typical gas car depreciation, which just adds to the money you save driving on cheap electricity.
Interesting. Of course, there’s a lot more to this story than just the parameters analyzed above. And the matter of whether or not you even could get enough EV owners to participate in such a program for it to be viable is still undetermined. How many of our readers would be interested in participating in such a program if it were available?
Is this a case of drinking EV flavor aid? In US, EV pays about 35MPG to 60 MPG gas car at the moment for base rate electricity, far higher for higher tier or some public charging. The money you save driving from “cheap” electricity is not as much as one would think, especially when gas prices are low like these days.
http://sparkev.blogspot.com/2015/10/money-mpge-for-various-ev.html
EV also depreciates, just like gas cars.
EV battery wear does not take into account reduced range with more wear. The inconvenience is not factored. This could be huge depending on one’s time value. I, for one, would not give up battery wear reduced range even if they pay me free car charging.
Battery replacement is large upfront cost where as gas cars are small incremental cost over time. Knowing that battery replacement will cost similar or more than comparable age used cars, I wouldn’t risk anything to reduce battery life, because dead battery out of warranty means junked EV.
Until battery cost and reduced range with wear is addressed, I don’t know if many (any?) would opt for V2G. One might be for the utility to “own” EV battery with much more generous replacement policy for reduced range, and EV drivers lease them. But we know how well battery lease usage model turned out for Renault: utter failures.
In California, Grid storage should be a no brainer. At night wholesale electricity costs 5c/kWh and at peak times a kWh often costs more than a dollar. But those prices are not available to regular folks.
V2G has plenty of hurdles ahead. There’s already a lot of sense to just control the charging power and we have the very same effect with less invested capital.
At the moment there is a lot of boilers in homes which are under utility control or should I say under control advice. Meaning the boilers keep temperature around 65-70C but when there is need to add more load to the grid those boilers turn on and heat the water to 85-90C. 50.000 pcs of such 9kW loads are pretty nice load (450MW). Those boilers enjoy nearly free energy in such conditions (~2c/kWh).
EV’s people tend to keep charged around 20-80% SOC during normal day. This will fix more close to 40-60% SOC (to keep the cells in good health) when the vehicle battery capacity rises. Tesla’s Model S will likely have P150D version by 2018. One pack will last for 35 years/1.500.000 km. And before anyone starts saying there is no need for such I would like to remind everyone thought cell phones need only limited CPU in 1990’s as ‘Why would calling require such power? It’s just relaying voice.’ This all becomes so much more valid when car-as-service operators max out the investment.
But as people have one week worth of range in the car all the time they charge according the cheap electricity cost.
For grid tied energy storages we can optimize the cell structures and chemistry. Those systems will be close $50/kWh sooner than many thinks. This is standard capacity vs power situation. Cycle life will be over 10k and calendar life is +20yr. This is the future we will see. Accompanied with abundance of nearly free solar energy (~1c/kWh). I love how the future looks now! 🙂