alt Hacker NewsI really wonder if part of the reason this isn’t more widespread is that utilities with variable rate electricity pricing would get burnt on it. Imagine charging during cheap time then dumping 5-20kWh back onto the grid during expensive time. You could have a positive ROI on a vehicle you regularly drive (timing permitting)
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In TX, the power producers, distributors, and retail electric utilities are (most commonly) different parties, so the latter two are very much interested in the type of decentralized time-shifting you mention since it smooths wholesale costs somewhat and reduces grid buildout and maintenance.
For EV owners in TX, its not uncommon to have fairly free charging overnight (just paying the distribution costs of 5-6 cents/kWh).
For homes with residential solar and batteries in addition to the EV, you can have essentially free power and EV charging due to time-shifting and incentives.
Residential batteries are still quite expensive, though, so it would be amazing to recruit those in the above EV to time-shift using V2H.
Why? That's the entire point of moving towards dynamic tariffs. In the systems I'm familiar with the utility company makes money through a fee charged on top of the market purchase/sale price, much like an investment broker.
V2H was popular among Japanese Nissan Leaf owners and there were tons of Leafs on cinderblocks with dead batteries used to milk incentives sold on used market for like $1k with 10 mi on the meter. Tiny household sellers are credited for sales for generosity, but apparently often just a noise that needs to be compensated by increasing power output at power plants to then just burn off. Great idea on paper, often not so much in practice.
Maybe. I did the math and in our area a Powerwall would roughly pay for itself over the speced lifespan of the device, IIRC that was just the cost of the device not the cost of installation. I did that calculation ~4 years ago, so maybe it has changed, but definitely do the math, I was surprised.
Why shouldn't utilities pay for this? You're provide grid load balancing. Theoretically their pricing should be considering this? It's not actually free to you since charging and discharging your battery costs money.
But naturally the situation is they want to be the ones paid the big bucks for such services.
No, the main barrier is concern over warranties for the vehicles.
In California, the law requires that vehicles still hold up to 70% of their original charge after 8 years and 75% in the future [1]:
> and d., to deteriorate to less than 70% for a warranty period of eight years or 100,000 miles, whichever first occurs, for 2026 through 2030 model years, and 75% for a warranty period of eight years or 100,000 miles, whichever first occurs, for 2031 and subsequent model years.
The law is unclear on bidirectional charging and whether this would give manufacturers an out. So they're cautious.
[1] https://www.law.cornell.edu/regulations/california/13-CCR-19...