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Comment by arethuza | Hacker News Reader

Demand at night is quite a bit lower than during the day and I suspect that's when most EVs will be charging - so that might help.

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Agreed. I used a bit of lazy maths to make the numbers match to give a simple illustration. I suspect we'll have more than 5 million vehicles charging daily, and overnight, given that there's almost 30 million registered vehicles right now. And there's also 22kW chargers as well.

And year-on-year, everyone uses more electricity. Definitely interesting times ahead.

On top of that, energy expenses for air cooling and conditioning will increase dramatically in many places due to climate change.

So we probably need to triple the grid capacity. It's very hard to do that with renewables only without opening serious risks. Not impossible though. And will definitely take some long time to deploy the necessary facilities.

air conditioning is one of the smallest issues (somewhat ironically), as the demand from it is the highest when sun is shining, meaning there is lots of PV Electricity available (and with roof PV no burden on the grid either). Heat Pumps in Winter are the bigger issue generally.

I'm not so sure. If you're still speaking about the UK then we'd have to have a spectacular rise in temperatures to make AC a problem. The UK is much cooler than the USA and continental Europe in summer, so it's very rare to have AC at home.

I don't think I've ever seen a home with AC in the UK - certainly not here in Scotland.

Come to the south-east. New build homes down here are heat traps. We have two portable units for the summer and are going to get a full unit next year. We need it. Our house gets to 30C inside and stays at that through the night.

At least one of my neighbours has air-con that I can see, and a couple of re-builds in my town that I can see from the road have them too. My utterly unscientific estimate would be 1 in 500 houses in the SE now have aircon.

You're probably looking into heat pumps. We added one when we moved in and we got another 10 years out of the furnace. What killed the furnace was 27 years of moving air. And parts were no longer available to replace the "squirrel cage".

Heating the house with natural gas (from the replacement furnace) is now cheaper than using electricity, which is not what I predicted when we put in the heat pump. But I didn't foresee fracking.

Anyway, heat pump gets us hot air in the winter, cold air in the summer, and lowers our bills.

A neighbor put in a well-based (as opposed to air, like ours) heat pump which I was very interested in. But it took them 3 days of drilling (rocky soil) and tens of thousands of dollars. So probably just as well.

I did some calculations on how much more renewable the UK would need based on demand over a given year, and how much storage.

With 20 times the current renewable, 1GWh of charged storage, and a perfect grid, starting on Sep 18th 2018, we'd be fine until September 30th at 18:15.

With 10 million EVs acting as a battery store, all topping at 50KWh and going as low down as say 25KWh, that would be 250GWh of storage, we'd last until September 30th at 19:30.

That doesn't count the extra demand of the EVs in actually driving.

If we had 50 times current renewable and that 250GW of storage we'd be OK.

> Demand at night is quite a bit lower than during the day

Germany currently has around 60 GW, during the day we had 77 GW:

> https://www.electricitymap.org/zone/DE

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