Understanding Solar Energy

One thing I haven't seen much coverage on is how to tap into the giant batteries we're driving around in our electric vehicles. These are much bigger than what's currently being deployed in houses.

The V2H standards are just now coming online: https://electrek.co/2025/02/21/nema-bidirectional-ev-chargin...

There might not even be any need for V2G or V2H.

Just charging your car when the demand is low is probably enough to drastically reduce the overall cost of the system. And this has basically no impact on the battery lifespan.

A trial in the UK resulted in customers earning up to £725/year [1]. With increased renewables on the grid leading to increased flutucations in the wholesale price of electricity, providing V2G/V2H will further reduce a customer's electricity bill on top of the savings offered by smart charging eg. Charge Anytime Tariff is 7p per kWh for EV charging [2] vs 27p kWh average Apr - Jun 2025 [3].

1. https://www.kaluza.com/case-studies/case-study-kaluza-enable...

2. https://www.ovoenergy.com/electric-cars/charge-anytime

3. https://www.nimblefins.co.uk/average-cost-electricity-kwh-uk

V2L is one of the reasons I bought the car I did - instead of getting battery backup for the random outages that PG&E gifts us (literally power drops likely to happen whenever we gust over 25mph), I installed a 12 circuit transfer switch and my 75kWh battery in the car can provide reasonable backup without running cables throughout the house (reasonable = 1.9kW max so no hair dryers or running toaster oven + microwave at the same time).

Newer vehicles (like 2025 Ioniq5) can do 12kW throughput (and many trucks can do 9+ kW already).

Once V2H standards are confirmed and deployed I would be able to integrate the Car batteries with home batteries and solar.

High demand is not the sole reason for outages.

Arbitrary vehicle to home/home battery/grid connection is indeed coming in very short order.

https://enphase.com/ev-chargers/bidirectional

There are other products already available to do it (DCBel), and it can be hacked of course, but at the current moment everything comes with substantial corner case blind spots, mostly related to grid-forming/following switching and to the resilience of the power electronics.

A Generlink would have simplied your transfer switch rewiring. Just connect the external 240V supply (be it your vehicle, batteries, or a fossil fuel powered generator), and the Generlink shuts down the grid connection and delivers to your regular main service panel. You might need to turn some circuits off when using it, but which circuits and when remains flexible and context dependent.