alt Hacker NewsI'm not sure what the laws are like in the USA I assume they are similar to elsewhere.
However I think there are two problems here that have to be solved:
1) you need to island your house, that is, physically disconnect your house from the grid
2) once you have disconnected the grid, you then need to provide some sort of pilot sine wave to allow the plug to function.
I have an islanding system for my (house) battery and solar, so in theory, I could have a bidirectional charger whilst being off grid. However both my car and charger don't support that (my charger is also deeply shit, and has no local API access.)
The bigger problem, which is tangentially touched on, is that vanishingly few chargers can actually support islanding. It makes the installation harder, and drives up the compliance and installation cost[1]. this means that you are taping together two disparate systems together (or going all in on enphase, which also has a limited local API)
There isn't a spec for a household systems to talk together to do energy management. currently I use homeassistant to monitor the variable electricity prices, car plug status and how happy the fucking powerwall is, so that I can make sure the car charges from solar, without draining the house battery to 0, or only charge at night when the price us uber cheap (and also not drain the house battery).
The amount of sysadminig to make that work reliably means that no normal person is able to achieve it. The problem for consumers is that there isn't any motivation for manufactures to work together on this. because they want to vertically integrate.
[1] The installation cost for what is effectively a very thin software wrapper around a local contactor is egregious.
> I have an islanding system for my (house) battery and solar, so in theory, I could have a bidirectional charger whilst being off grid. However both my car and charger don't support that (my charger is also deeply shit, and has no local API access
...
> The amount of sysadminig to make that work reliably means that no normal person is able to achieve it. The problem for consumers is that there isn't any motivation for manufactures to work together on this. because they want to vertically integrate.
We are in a very similar position. The issue is every company in this area is like you say: deeply shit with limited local API access. Setting up bidirectional charging in the UK is technically, really not that hard, especially with islanding handled at the household level.
Good luck trying to get someone willing to put their career and certifications on the line to actually do it though.
Part of the challenge is finding an electrician willing to work like a sysadmin and do things because they know how they work, rather than only doing things they've explicitly been taught as in line with (dated) regulations.