Selling electricity is compensation, like with solar panels. You only need hourly energy prices to make it profitable. Plus an app that does the profitability calculation and discharging.
Sounds similar to Uber using a contractor vehicle's hidden depreciation and maintenance to shift the real cost of their service.
I doubt the hourly price will ever truly be fair to individual car owners. Maybe we'll start to be asked whenever we plug in our phones to tip the owner of a car our electricity is coming from.
If there are consistent price cycles and a good API for reading price, it should be pretty easy for an EV owner to control how much they interact with the arbitrage opportunities with some simple rules. Ex. "only sell if it cost at least 15% less to charge", "always charge to X%", "charge to 70% if < $Y", charge to 100% if < $Z", "never sell below X%"
The aesthetic vibe of having an autonomous energy trading bot in my garage is attractive to me.
Part of the issue isn't the controls to do that it's that the prices to compensate wear on a battery are a) likely significantly higher than the base price and b) pretty hard to calculate.
Yeah, I'd try to model the deprecation cost of the battery to some extent while tuning my magic numbers in the trading bot settings.
~1,500 cycles per $16k battery replacement. Shouldn't sell a full cycle for less than ~$15. Don't arbitrage a 1% point of battery life unless it yields at least $0.15. Might just set it at $0.20 per 1% for healthy margin/price-in hassle of battery replacement.
You're not actually getting the full 100% out of a cycle probably when the utility drains it though. They'll take a portion of your battery then it'll either charge up again using a partial cycle or your car will get charged at home like normal where the math you did is closer.
It's also not super clear how much wear small charge discharge cycles does on a normal battery if it's not in the bottom or top 20% of the battery.
I doubt the hourly price will ever truly be fair to individual car owners. Maybe we'll start to be asked whenever we plug in our phones to tip the owner of a car our electricity is coming from.