[Retric]

Let’s assume at scale you’re buying seasonal power for 0$ so efficiency doesn’t matter and selling it at 10c/kWh given 1$/kWh and a once a year discharge you might break even in 10 years which looks fine except...

1$/kWh is only storage for already existing hydrogen. For this application you also need equipment to both produce and burn it which adds to these costs. Hydrogen generation can’t depend on 0$ prices for very long each week in the off season so you either need a lot of excess equipment that’s rarely used or be willing to pay more for electricity. Further, nobody building a grid would be willing to depend on seasonal storage running out on the last day it’s needed. So you need a large guaranteed storage surplus alongside redundancy in your generating capacity.

Start running the numbers and the annual ROI doesn’t look to be even enough to pay for the interest on your setup costs let alone profit. It might have some ultra niche applications but the economics don’t seem to work out for large scale deployment.

[pfdietz]

Yes, but the producing and burning is not proportional to the amount of energy stored, but to the rate at which the hydrogen is produced or consumed.

In the 100% renewable grid, electricity actually will be in surplus a good part of the time, because so much excess capacity would be installed. This is not the case now, so you can't use the current frequency at which curtailment occurs as some sort of baseline.

Yes, you'd need excess storage so it doesn't run out. Fortunately hydrogen storage is cheap. This is another argument for hydrogen over batteries.

You can run the numbers and see that in a hypothetical system for providing steady power in Germany, including hydrogen storage can cut the total cost nearly in half (subject to assumptions, of course.) Doing it with just wind, solar, and batteries ends up being far more expensive.

[Retric]

The amount of energy stored or is still limited by the rate it can be generated.

The absolute best case for seasonal storage is 1kW * 9 months = 6,480 kWh per 1kW of equipment if you are willing to pay unlimited prices per kWh.

However if you are depending on 0$/kWh which hypothetically occurs 1% of the time you are down to 55kWh per 1kW of equipment. In a world with mass storage wholesale prices will spend less time at 0$ so what matters is the prices when you’re operating not historic prices before you build these facilities.

PS: Conversely, if you’re using that stored energy the grid isn’t going to have a deficit 24/7 the entire winter at your maximum production rate. If you average 8 hours a day for 2 months that’s 480 hours of operation per year. Gas turbines are cheap but not that cheap.

[snordgren]

Here in Europe peak electric prices have been far above $1/kWh, rising to around $7/kWh in the worst-hit regions.

Due to the build-out of wind power we have also had a few nights of negative electricity prices in recent months.

If we had a hydrogen energy storage facility, it could probably have recouped quite a portion of its capital costs this year, depending on its scale. Europe will not be building much base load power in the coming years, so the imbalance of the grid will only continue to rise, allowing for more business opportunities in the energy storage sector.

[Retric]

Europe is experiencing those prices due to a dependence on fuels it doesn’t produce and a lack of daily energy storage.

Extrapoatgng prices to stay the same when you swap energy sources and introduce two different kinds of large scale energy sources is clearly wrong.

Ultra low or ultra high prices will represent a small chunk wholesale prices after you construct long term storage. You can’t build equipment that’s utilized 0.01% of the time and expect significant profit.