Everyone always forgets that they only perform at less than half of their rated capacity and require significant battery installations. Rooftop solar plus storage is actually more expensive than nuclear on a comparable system LCOE due to their lack of efficiency of scale. Rooftop solar plus storage is about the most expensive form of electricity on earth, maybe excluding gas peaker plants.

While I agree with your general assessment, I think your conclusion is a bit off. You’re assuming 1kw/m^2, which is only true with the sun directly overhead. A real-world solar setup gets hit with several factors of cosine (related to roof pitch, time of day, day of year, and latitude) that conspire to reduce the total output.

For example, my 50 sq m set up, at -29 deg latitude, generated your estimated 30 kwh/day output. I have panels with ~20% efficiency, suggesting that at 60% efficiency, the average household would only get to around half their energy needs with 10 sq m.

Yes, solar has the potential to drastically reduce energy costs, but even with free energy storage, individual households aren’t likely to achieve self sustainability.

Average US home.

In Europe it is around 6-7 kWh/day. This might increase with electrification of heating and transport, but probably nothing like as much as the energy consumption they are replacing (due to greater efficiency of the devices consuming the energy and other factors like the quality of home insulation.)

In the rest of the world the average home uses significantly less.

That's a bit of a non-statement. Virtually all prices increase because of money supply, but we consider things to get cheaper if their prices grow less fast than inflation / income.

General inflation has outpaced the inflation of electricity prices by about 3x in the past 100 years. In other words, electricity has gotten cheaper over time in purchasing power terms.

And that's whilst our electricity usage has gone up by 10x in the last 100 years.

And this concerns retail prices, which includes distribution/transmission fees. These have gone up a lot as you get complications on the grid, some of which is built on a century old design. But wholesale prices (the cost of generating electricity without transmission/distribution) are getting dirt cheap, and for big AI datacentres I'm pretty sure they'll hook up to their own dedicated electricity generation at wholesale prices, off the grid, in the coming decades.

Most large compute clusters would be buying electricity at wholesale price not at retail price. But anyway solar and battery prices have just reached the tipping point this year only now the longer power companies keep retail prices high the more people will defect from the grid and install their own solar + batteries.

I am not certain because I've been very focused on the o3 news, but at least yesterday neither the US nor Europe were part of China.

But data centers pay wholesale prices or even less (given that especially AI training and, to a lesser extend, inference clusters can load shed like few other consumers of electricity).

And this is great news as long as marginal production (the most expensive to produce, first to turn on/off according to demand) of electricity is fossils.

It's the same about using the cloud or using your own infrastructure there will be a point where building your own solar and battery plant is cheaper than what they are charging they will need to follow the price decline if they want to keep the customers if not there will be mass scale grid defections.