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Comment by _delirium | Hacker News Reader

It's definitely an opportunity, but the price at peak production periods is near zero precisely because nobody has yet figured out how to soak up these kinds of transient production peaks effectively, with sufficiently fast ramp-up and scale. It won't stay at zero if some big users figure out how to use that energy profitably. Though that wouldn't be bad overall. If some large users did figure out how to take advantage of these periods, it'd be a step towards smoothing out both grid pricing and usage.

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If the "hydrogen economy" people ever figure out a way to make the equipment and fuel cells economical, cracking hydrogen from water at times when power is $0.00 per kWh could be one method. Takes a massive amount of amperage. Store it in tanks and use as needed through giant fuel cells.

Energy losses from this scenario are high enough that there are probably other usage scenarios that would beat it. It's certainly the case that there are already many peak-storage solutions deployed and none of them involve hydrogen.

there are already many peak-storage solutions deployed and none of them involve hydrogen

That seems like an overstatement. There has definitely been considerable research into using hydrogen as "peak-storage solution", and I think some approaches are actually being deployed. For example, here's an NREL story from last year: https://www.nrel.gov/continuum/energy_integration/hydrogen.h...

The article agrees with you that the current inefficiencies of the round-trip to the grid are large, but claims that generating hydrogen as a vehicular fuel using excess solar and wind power does make sense. So if the parent was envisioning those "giant fuel cells" as being mobile (or located somewhere really remote), then he's not that far off.

OK, so what % of peak storage solution is hydrogen?

That’s a demonstration project and to the extent that it’s “deployed”, so are tokamaks.

Hydrogen may be feasible for peak balancing but it seems correct to say that it is not currently used this way.

> Store it in tanks and use as needed through giant fuel cells.

Or just push it into the gas pipeline grid, it provides storage capacity and has the applications already waiting (the amount of hydrogen allowed in the final mix varies between regions, but we are a long shot from displacing natural gas by that fraction, worst case you'd have to add in a slightly lossy methanation step).

It works, a well developed gas grid already has all the storage capacity you could ever need and you wouldn't have to scrap your existing gas peakers even after scaling to 100% renewable. Perfect migration paths tend to be disappointingly unspectacular.

Is there really nothing that we could do with this excess energy? Couldn't we purify water or run simulations or something similar?

It's not economically effective to run a supercomputer only during peak times.

Some Nordic countries that have large district-heating systems have started experimenting with dumping the excess energy into those.

Electricity to heat is not that efficient; normally district heating systems run off of the waste heat of electricity generation. Are you talking about an example where the waste heat isn't enough to power the district heat?

Actual energy to heat is only useful in a true excess energy availability situation, but usually you'd start building up heat storage to decouple heat availability from electricity demand, which would otherwise be a problem with cogen plants. And heat storage is so much cheaper and efficient than electrical storage, so you want to run your cogen in sync with electricity demand. Once the heat storage is there, it becomes an absolute no-brainer to also use it when you have excess electricity to dump (as electric heating is 100% efficient, it's the production of electricity in thermal plants that makes electric the worst form of heating).

We use heat pumps for district heating in Drammen, Norway. Run this through your favourite translation engine to read all about it: http://www.energi.no/brakeroya-varmesentral-apnet

Pumped storage hydroelectric plants seem the obvious target to me https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectric...

Desalination does seem like a good target. I think synthetic hydrocarbon production will be a good place to dump excess too. Pharmaceuticals and plastics aren't going anywhere, and I bet they'd appreciate a cleaner starting point than bitumen.

Electric cars have the obvious potential to absorb peaks. With range on recent models far exceeding typical daily use, it becomes increasingly easy to make charging dependent on supply.

Cryptocurrency miners have the fast ramp-up and scale required.

But they're profitable at high energy demand times too, so there's no incentive for them to run only during low demand.

Cryptocurrent miners have a strong incentive to locate in places where the $ per kWh rate is consistently low 24x7x365, not just for peaks. Such as near a hydroelectric dam in east Wenatchee WA. Mining also requires very little in the way of network connectivity, maybe 10Mbps at most, so it can be located just about anywhere.

Relevant article from this week regarding miner activity in that area:

https://news.ycombinator.com/item?id=16551848

It appears empirically that they don't. If they did, there wouldn't still be peak-production periods when energy was near zero cost, since they would've arbitraged that out.

Does that run the risk of being damaging to the currency network -- could transient spikes of mining push up the difficulty and thus affect functionality once the energy price goes back up?

You don't even need energy spikes for that, it already happens when hashrate is mobile between different networks.

That's actually what made me think of it (Nicehash pushing up the difficulty on the smaller coins); I just wasn't sure if something more cyclical would have the same effect or be easier to counter.

Cryptocurrency mining isn't enetgy constrained. Right now it it is capital constrained. Your primary costs are fixed upfront purchases of ASICs and GPUs.

It's kind of entertaining that you mostly said the same thing as the person you replied to, but apparently don't realize it.

Why do you see it as the same? Gibbon1 points out that there is a current opportunity for a business that can take advantage of sporadically available almost free power, and _delirium extends this to say that paradoxically this opportunity will disappear as soon as there is a business that can use this power. Gibbon1 may or may not agree that the opportunity will disappear once it's being utilized, but this wasn't mentioned in his comment. So what is _delirium failing to realize?

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