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Comment by tjansen | Hacker News Reader

> Solar, wind and batteries are cheaper and money is limited.

How can you even estimate the cost of batteries? Insane amounts of batteries would be needed, capable of storing all of Germany's energy needs (including transportation and residential heating) for 10 days or so. That would be at least 10 TWh, as Germany currently uses about 550 TWh per year.

The global production of lithium ion batteries in 2018 was 290 GWh (1000 GWh = 1 TWh), expected to increase to 2 TWh per year by 2028 (https://www.statista.com/statistics/1247625/global-productio...).

In other words, even if Germany would buy every single battery produced on Earth over the course of 5 years, it probably wouldn't be sufficient to provide energy for 10 winter days without wind.

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>We find that low-wind-power events are less frequent in winter than in summer, but the maximum duration is distributed more evenly between months. While short events are frequent, very long events are much rarer. Every year, a period of around five consecutive days with an average wind capacity factor below 10% occurs, and every ten years a respective period of nearly eight days. These durations decrease if only winter months are considered. The longest event in the data lasts nearly ten days.

https://iopscience.iop.org/article/10.1088/1748-9326/ab91e9

In your once in a lifetime event I'd be happy if we used a bit of gas. This is something, after all, that Japan also had to do for years after Fukushima went kaput.

Bear in mind also that demand for heating and transportation can be timeshifted. An Octopus tariff in the UK already allows for this. We've barely scratched the surface of whats possible here because electric grids are slow to evolve to this new reality.

"I'd be happy if we used a bit of gas."

Gas alone does not produce electricity. Gas power stations do. This means building enough gas power stations to cover power requirements of the entire country, then having them sitting most of the time idle there, "just in case".

This is the core of the problem: wind and solar need to be massively backed up. You cannot rely on them supplying even 5 per cent of their nominal capacity if the weather turns against you.

Such a massive backup is eye-wateringly expensive, too. And it consumes concrete and steel, two elements whose production is carbon-intensive.

>This means building enough gas power stations to cover power requirements of the entire country, then having them sitting most of the time idle

If you assume:

* We dont already have the infrastructure.

* Power cant be imported.

* Power usage cant be timeshifted.

* Power cant be stored in batteries.

* 10 day periods without wind and sun are routine.

Then yes, it might get expensive.

Well, then make it 5 days. That still needs more capacity than the global battery production per year.

Smart grid can solve this problem, when appliances will report of their needs and abilities to the grid, and then the grid will schedule power delivery to meet the demand.

What kind of appliances can wait for several hours? The only example I can think of are cars that are being charged over night.

Water heaters, cars, washing/drying machines, power walls, battery powered devices. Electric teapot, microwave, cooking stove can operate at half of power when demand is very high. They can report to and receive instructions from a smart power meter.

I forgot pumped storage which is apparently 8 TWh

https://www.hydropower.org/country-profiles/germany

Do you really want to bet there will be no viable battery technology for another 50 years? It's kind of a high value research topic right now.

50 years? I'd hope we have fusion power by then. But it doesn't look like there will be enough batteries for wind power in the next 20 years.

There is, however, plenty of hydrogen in seawater.

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