What are the current vehicle-to-grid options?

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Hi Bryce – with EV sales accelerating, we now have four Teslas in our apartment block, using wall chargers connected to the remaining available slots in the switchboards. These include:

• my Tesla S with a battery capacity of 85 kWh
• one Long-Range Model 3 Performance with a capacity of 75 kWh
• two Model 3 SR+ with a capacity in the range 50–62 kWh

… for a combined capacity of 260 kWh.

What options are there currently for V2G (Vehicle to Grid) and/or for soaking up the solar output from the array recently installed at the complex?

Cheers

Richard

Hi Richard – in answer to your questions, I’ll start with the V2G part and circle back to solar at the end.

Currently there are no V2G systems commercially available in Australia for installation. There are also a number of other delays with V2G that mean it may be a while before it becomes a viable option. At the moment these include:

1. No V2G bidirectional EV charging systems are currently approved for installation in Australia;
2. Bidirectional charging is via the DC port and currently only the CHAdeMO standards include bidirectional charging protocols. (i.e. Renault Zoes available here will never be able to do it as they are AC only, and the new ZE50 Zoe, which is yet to be offered in Australia, is CCS2 so it won’t be either – see point 2);
3. CCS2 will have bidirectional standards in place by 2025 (see here) – so it’s likely only later model EVs with CCS2 will be capable of it, unless the manufacturers roll-out software upgrades (and extend battery warranties to cover V2G) for older EVs;
4. Anyone wanting to do bidirectional charging will need to upgrade to a smart, DC, bidirectional one when V2G becomes available here;
5. Sadly, there is still a bun-fight here in Australia as to what smart-grid communications protocols to use, and no date for a decision;
6. As a final note: the inbuilt Tesla AC charger does NOT have bidirectional capacity – that was a rumour started a couple of weeks ago by a well-meaning vehicle researcher, but it was disproved a few days later (and original author accepted he had made an error). Sadly, the fake-news presses still seem to be recycling that original report….

Take-home messages:

Yes: EVs are currently very good for soaking up excess solar (especially if paired with an EVSE that can track and match solar output to EV charging rate);

No: Australia (and most of world) will not be doing much V2G for at least 5 years, so it is too early to make decisions regarding setting up current homes, units and apartments for it.

As a final note: I have a sneaking suspicion that V2G will not become a major player in the domestic market – especially as PowerWalls will start to use recycled Tesla batteries, so the price of a permanently installed, 24/7 reliable system will plummet and/or sizes could be easily increased as used EV batteries start to reach the market.

Same for other fixed battery systems – that to me is the likely future for EV batteries: to be recycled into fixed systems in homes, businesses and ‘big battery’ systems like Hornsdale in SA.

V2G will have its place though: it could be a boon for fleet owners who can afford bidirectional DC charging equipment as they can offset power pricing with providing guaranteed amounts of grid storage to take advantage of V2G tariff structures.

Will homeowners be able to get V2G tariffs? I personally doubt it as the car is not always there. (Ask yourself the question about what happens to a home V2G system without a battery if the power fails or future new variable TOU (Time Of Use) tariffs based on V2G have a power price spike when you’re away in your EV?).

Apart from all this, you have the issue of always having to plug-in when getting home and unplug when leaving. As an owner of a long-range EV (a Hyundai Kona electric) I plug-in once or twice a week at most. Doing so several times a day to me seems a pain and something easily forgotten if charging isn’t needed!

On the other hand, perhaps a market for aggregator businesses will start where you can subscribe your V2G system to. Who knows – that is getting a long way out in terms of predictions.

As for apartment buildings? It’ll need a good percentage of vehicles there to be electric before you reach the sort of fleet EV V2G buying power to get a V2G tariff and justify the expense of bidirectional DC chargers. I am also guessing that sort of arrangement is still 10 – 15 years away (but I’ve currently run out of crystal ball polish: it seems cloudy around that area 😉

If looking for a solution now, I would suggest your apartment block with PV look into a networked set of AC EVSEs and investigate how to integrate output monitoring of the solar output with the EVSE charge rates. (That should be possible now with existing hardware).

Cheers

Bryce