EVs are great for the environment!

https://www.youtube.com/watch?v=48Khw8H7c8c

tomo; Robert: thanks for those videos - tricky business!
It's going to be interesting to see how the whole V2G thing pans out as it's nowhere at the moment, afaics.
It's often touted as part of the solution to backing up wind and solar but there's a scale problem. If we take some silly numbers, say 5m EVs each able to supply 30 kWh to the grid, that's 150 GWh. Spread over just 24 hours of a hypothetical dunkelflaute that equates to a little more than 6 GW. Yet, without gas and with almost no nuclear, the grid shortfall could easily reach 20+ GW.
Imho, V2G is a mirage.

A fire at a battery recycling plant in Ayrshire. There are a few question marks about how good for the environment all these green ideas are, but I have to admit it's quite festive with the rosy glow and individual cells shooting off like skyrockets.

Could do with some of that warmth here.

tomo,
That crispy fellow was trying to nick the copper, but the same Darwinian selection mechanism might be in play for siphoning from EVs.

I liked your choice of video to demo grid synchronisation. I think I've previously posted my own favourite which does less to explain, but is quite exciting: hooking up a 350kW hydro station.

Just musing on it, the seat of my pants tells me a couple of things:
  1. There's no way to have an independent synch reference for an arbitrary position on the grid (atomic clock or whatever).
  2. It's impossible to synchronise an arbitrarily meshed grid.

1 comes because of propagation delay; the AC signal works its way up and down the line somewhat like tides around the coast, so in addition to a universal time reference, your location would need a propagation time offset.

2. comes from the fact that a typical mesh would have different propagation delays along the multiple paths between pairs of nodes.

I think it's preferable that these problems are sorted out as they are at present: empirically. At any node, I am obliged to synchronise with whatever is on the line already. It's imperfect, in the sense of an atomic clock, but flexible, with no "master". A bit like the internet.

tomo; apologies if I'm being thick but why would a generator be any different to a solar array wrt grid connections, etc? OK, 13 kW is bigger than most solar systems but they both produce 240v AC.
Is it something to do with the mechanical nature of a genny, needing to get things "in phase" as power stations do, whereas some electrickery can do that for the DC output of solar panels? Such kit must exist for things like small-scale hydro.

Quite a few commentors on the EV forums I visit have solar panels, often with batteries. Export does not seem to be a priority for them, probably because the rates are rubbish, as you say. Many charge their EVs during the day, if they can and then top up on cheap overnight tariffs. They also use their batteries to time-shift their consumption by charging overnight for use in the day. Clearly an export-enabled EV would help with this as EV batteries are typically much bigger than domestic systems - hence the idea of "re-purposing" old EV batteries for home use. However, as you say, battery life is a consideration since it is influenced by the number of charging cycles.

tomo; in your post about V2G you said:
"Even though it's been talked about for what, 20 years+, there is still no agreed, widely recognised standard for grid synchronisation that allows for net metering"
I am probably misunderstanding but isn't this well-established for roof-top solar?

On that subject, am I correct that domestic solar shuts down during a power outage for H&S reasons unless there's extra kit fitted which isolates the house from the mains, allowing it to continue running on solar - if it's working, obvs. Siad extra kit is not cheap, aiui.