I mean maybe if we invested in our grid here in the Netherlands. The government's answer to increased renewable has been to remove incentives and encourage everyone to get their own batteries. 😞

How good is the link?

Here in Estonia, two problems we face are that the two Estlink cables connecting us to Finland (which has a nuclear plant! yay!) are sometimes down for maintenance, and also they're sometimes fully saturated in the winter. In fact when that happens, power prices go up a lot because our national consumption can reach 1600 MW (actually new record this February was 1723 MW) and when the main shale burning plant is down for maintenance (which is about once a week for 8 days at a time in the winter when it would be useful) we're pretty much at the mercy of wind and and the Finnish nuclear plants. Oh and since we're the bridge between the rest of the Baltics and Finland, we don't really keep all of what is transferred over Estlink, the Latvians and Lithuanians are part of the same grid so their demand gets added to ours.

Point being, our grids might not be closed, but particularly when talking about overseas connections, there are bottlenecks.

Well the solar power you'll have to provide yourself (or apparently they'll also rent panels to you?). The technology doesn't seem too far-fetched, but the economics of it don't make sense for me at least.

Technology itself should be simple. Use excess solar power throughout the summer to produce hydrogen (not difficult), store it safely (more difficult - they claim to store it in solid form which makes me wonder how that would take place in an automated fashion underground). Then in the winter, turn hydrogen back into electricity and use waste heat for heating water.

But the fees exist all year round. If I had solar panels, electricity would be nearly free to me in the summer (at peak we get 18 hours of sunlight in the summer... and 18 hours of darkness in the winter). The annual cost of this system would pretty much add up to what my energy costs are already without any solar panels though. If I just got myself solar panels and a battery that can last me ~12 hours in the spring or fall, I'd only REALLY need to be paying for electricity for about 6 months a year.

I totally agree. Hopefully the approach works and isn't locked by some horrible patents so that other companies are prevented from actually selling it.

Monthly base fee starts at 300€, which will be reduced by [...] which can amount to up to 150€

Yeah if it was more than the 10 MWh they've mentioned on their website, perhaps it would be good enough for my house. But I think I reached over 2000 kWh of electricity consumption a month this winter thanks to my heat pump and possibly more than that in briquettes that I use for my central heating furnace. The 10,000 kWh they talk about is sadly not enough for my soviet-era built house, nor is my roof big enough for a meaningful amount of solar (it's complicated... big house, small roof, not all of the roof useable for solar). If I'd have to get 2 or 3 units and they end up costing me significantly more than the 300€ a month? No thanks. My highest electricity bill in the winter was about 330€ and yes, I also burned about 500€ worth of wood briquettes that month, but in the summer I pay less than 100€ and this was a freakishly cold winter, so normally it wouldn't cost as much (and I'm also now older and wiser and will keep a bigger stockpile because the prices do go up in the winter, something I've experienced before).