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Comment by tempestn | Hacker News Reader

The problem with using excess power for things like that (or desalination per sibling comment) is that the infrastructure to do these things is expensive, and it becomes less cost-effective if it's only used part of the time, when the energy is available.

The one application I'm aware of that can cost-effectively use excess power of that sort is crypto mining, since there the vast majority of the cost is electricity; the capital cost is relatively low. Unfortunately it's arguable whether it does anything useful besides enriching the producer.

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>The problem with using excess power for things like that (or desalination per sibling comment) is that the infrastructure to do these things is expensive, and it becomes less cost-effective if it's only used part of the time, when the energy is available.

Not if you reverse the grid - instead of providing power to the nodes it takes excess away to scalable workloads. And you have grid access as a backup.

It's nothing to do with the organization of the grid.

Almost any "scalable workload" actually capable of scaling up will have a high $$$ upfront cost for all the machinery / infrastructure involved.

If a decarbonation plant costs many millions of dollars to set up, nobody is going to let it sit idle waiting for some excess power.

The best use case for smoothing the demand curve IMO is thermal "storage". While production is high, people can crank the AC or heat. That way they don't have to use as much energy when production is lower.

Yes, that's a good one. Can even be automated to some extent using smart thermostats. Water heating too. Even without the thermal storage element though, there are lots of loads than can be shifted using a financial incentive. Clothes washing and drying is a good one. Electric vehicle charging too. Even if they aren't used to feed back into the grid, just having people charge when power is plentiful will make a big difference as more electric vehicles are added to the system.

Electric vehicles are really the best option IMO - as long as it’s fully charged in the morning when it’s needed, most drivers won’t care if it charges at 9pm or 3am.

I’m less certain about the other things - not many people will eg. put off a load of laundry to a less-convenient time to save 21 cents. And if my partner is too hot because the heater has been running for 30 minutes I really do not want to have a discussion with her about “thermal storage” :)

IMO the better application of the heating ones would be to have people opt-in to potentially having their heating or air conditioning disabled for short periods of time if necessary, but even if it isn't, they get a credit each bill. If there's a spike though, the power company could shut off those circuits remotely, freeing up some room. It would just be used for smoothing of short-term spikes.

I believe in some places this is already done.

This is pretty much the worst implementation of this idea. Nobody is going to be happy stuck in a 85F+ house with no way to cool it. It is also seriously dangerous to just shut off heating randomly. The credit would have to be impractically large for people to participate voluntarily.

It is so much nicer to cool/heat pre-emptively. The power company has a very accurate view of what the next 12-24 hours will look like. If they know The sun will be shining bright and there will be an excess of solar energy, they should crank up people's AC so that they don't need to draw as much power later in the day. This way we smooth the demand curve without letting pipes freeze or giving people heat stroke.

No one is getting heat stroke from having their AC shut off for a few minutes. I'm talking about short term spikes. I don't think many people are going to want to be freezing in the morning to avoid using power when the sun's up later in the day.

But these elaborate uses for excess energy are easier to do at scale using the existing grid. You have a specialist centre in a single location that can take excess power from across a large area.

Yes this is what I was suggesting would probably make most sense - you keep the existing grid even if you distribute the production.

We do this will rooftop solar cells, so the precedent already exists.

You mean you can cost effectively use the excess power to produce even more heat?

Once the power is produced it's going to become heat regardless, so if you're not able to scale down generation you're going to get that heat. But as I said, it's certainly debatable whether there's any value in that type of work.

The most obvious use for excess power is surely storing it. In a battery, a flywheel, a gravity storage system, compressed gas—hugely economical.

Yes. But storage is easier at scale using the existing grid. A large battery storage site can take excess power from across the grid and get economy of scale.

  > Unfortunately it's arguable whether it does anything useful besides enriching the producer.

I don't see how that goal is problematic given the use of a carbon-neutral energy source. I actually see it as an advantage, something that might help speed the adoption of fusion energy and thus get us off hydrocarbons.

You could always run Folding@Home or something in that vein.

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