[LINK] Electric Vehicles

Tom Worthington tom.worthington at tomw.net.au
Tue Jun 22 08:20:52 AEST 2021


On 21/6/21 1:31 pm, Karl Schaffarczyk wrote:

> I've really got to wonder about the whole thing about V2G or V2H ...
As do I, not being an expert on this stuff.

> ... trouble due to simultaneous grid use for charging vehicles?

No, but so far the proportion of electric cars is low. Norway has the
highest at 13% electric.
https://en.wikipedia.org/wiki/Plug-in_electric_vehicles_in_Norway

But with each car charger drawing 7KW, ten million would need 70GW. If
powered by the type of gas plant recently announced by the federal
government, this would cost $60 billion.

> ... struggling with Summer time peaks ... roll-out of solar ...

As far as I know, the incentives for solar were not targeted
at the summer peak, but to increase the proportion of renewable
energy overall.

> ... peak on a hot day ... turned into a double peak ...

The so called "duck curve": https://en.wikipedia.org/wiki/Duck_curve

> Off peak hot water systems used to pick up much of the night ...

Yes, we had off peak hot water where I grew up, with the tank sitting on
the floor in the bathroom. It occasionally made a musical buzzing noise,
from the control signal sent over the power line. You had to time your
bath to fit with the off-peak.

> ... electric hot water systems being ripped out and replaced ...

We may even see old fashioned resistive hot water systems make a
comeback, if the additional solar panels to power them are cheaper than
a heat pump.

> ... car's battery to feed back into the house/grid is a short-term 
> ...

Batteries are not going down in price as fast as expected, due
to the demand for electric cars. Also the batteries in cars are
effectively free, due to range anxiety. So the only cost is a V2G charger.

> ... why prematurely wear out your car ...

If you only use 10% of the capacity of the battery in your car, it will
not wear out before you replace the car. Even when the battery is no use
for a car, it could be repurposed for stationary applications.

> ... special tariffs to EV owners ... People obey their hip pockets!

People don't necessarily make rational choices with energy, which is one
way companies make their profits.

> In the long term, household batteries and grid-owned batteries will 
> work with solar and wind ...

Yes, and we will likely also need pumped hydro in the mix for storage.
But unfortunately Australian governments are not good with "long term"
and come up with ideas, such as a gas fired power station with no gas 
supply:
https://www.abc.net.au/news/2021-05-14/kurri-gas-plant-could-be-running-on-diesel-for-months/100138244

Compared to that, V2G is relatively sane.

> Cars feeding power to houses and the grid will have nothing to do 
> with it. ...

Perhaps not. But most cars spent most of the time parked, doing nothing
useful. If they have a charger plugged in, we might as well use it for
something.


-- 
Tom Worthington



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