[ffgjgf1]

> Just by buying an electric vehicle I already have more than enough batteries to solve these problems for my household.

Not if you live in Northern Europe. Solar is basically worthless there during winter. I’m not even talking about polar nights, just places like Denmark where the difference in production between January and June is 20x. No batteries (that we know of) would solve that.

[moogly]

Indeed. I live in Northern Europe and have a 17.2 kWp solar plant. During the summer, I see ~100 kWh uselessly (for me) go to the grid every day for a pittance, and I can't really use it.

4 months of the year (almost 5 if it's a really bad year like last year), there's virtually no production.

I work in the smart energy field, including with home batteries. The de facto standard size is still 10 kWh because the promised drop in price hasn't yet materialized on this market. I'd fill that up in 45 minutes during a sunny summer day. I maybe can use half of that during the night. If I were to charge my car during the night, then sure, I could use that, but it's just 10 kWh. That's like an 1/8th of the car battery.

50 kWh? Okay great, I'd fill that up in 5 hours. Don't really know what I'd use those 50 kWh for. Charge my car? Okay sure, but I don't drive every day, and never in the morning, so it makes so much more sense to do solar surplus charging once or twice a week. You rarely want to charge to 100% SoC anyway, and you should probably leave some additional capacity for FCR purposes.

100 kWh? The problem is that in summer when I can fill that in a day (assuming max power scales with the capacity), I cannot really empty the battery because my consumption is so much lower during the summer. I will only top it up a little bit every day at best.

What I really need is a fucking 10 MWh sand battery underneath my driveway that I can seasonally charge and then use during the winter for heating. Maybe it could also keep my driveway snow and ice free? Who knows.

And A/C in the summer I guess. That is actually what I'm going to get, because it turned out to be more stressful and agonizing to see 100 kWh go out on the grid for almost no monetary gain than I thought it would. Call me egotistical I guess.

Domestic solar is kind of a scam. I knew that going in, but I didn't anticipate the accompanying stress.

[oezi]

1. The price drop for batteries has been huge. They are down to 3000 EUR where I live.

2. Domestic solar is just a way to save money. If you bought more than you need then you wasted money. A typical consumer would be fine with 10 kwp system + 10kwh battery which in Europe costs now less than 20,000 EUR.

[pfdietz]

This is solved by also using wind and hydrogen. Europe has salt formations that could store millions of gigawatt hours of hydrogen, far more than they'd need for long timescale leveling of variable supply.

[olddustytrail]

Denmark gets 67% of its electricity from renewables, mainly wind.

[kobalsky]

doesn't long-distance power transmission solve that problem? just put the solar panels somewhere else?

[travisb]

The 'somewhere else' is a big issue though. In order to deal with Northern Europe winter power demands you probably want those solar panels to be on the Tropic of Capricorn in the southern hemisphere.

That's along ways away. It'll take a lot of costly electrical infrastructure to move that power.

Even worse, if you want to work during the night, you also want the solar panels about 45 degrees west. So like in South America. Tough luck for those places where that sweet spot is in the middle of a large ocean.