Can’t we power a big laser and point it at space or something instead? Anyone got a dumber idea?

There are so many things that are energy intensive and not really economically viable: co2 capture, crypto mining, "green" hydrogen, we could see a world soon where a large scale BESS would have an on-site dummy load that does something useful with that electricity

The problem with all those things is that they are ridiculously capital intensive to set up, and then they sit idle 80% of the time Worse, the whole point of negative electricity prices is that they're an inefficiency in the market which ideally will eventually be optimized away. Then what do you do with your billion-dollar plant that can only run with negative prices that no longer exist?

You're assuming the way they get optimized away isn't by these sorts of plants.

I guess the problem with building a pure energy waster is that it could only operate every now and then, and it's not guaranteed to see negative prices in a few years from now. So, might not be all that profitable.

Use the electricity to heat up a lump of iron to a very high temperature, than use electromagnets to fling it into space?

If you heat up iron to very high temperature (>770°C), it's much harder to fling it using electromagnets.

Ah that's annoying. Fine, we use the electricity to heat...uh...molten salt encased in stone, and to pull back a very big heat-proof slingshot, and after a threshold it lets go and launches it into space.

Obviously the complaint is about the changing atmospheric absorption properties as a side effect of the generation side, not the heat from using the power.

Either way I think people are overthinking it though.

Isn't this the basic description of what a gravity battery should provide?

No, because his situation is basically that the gravity battery is already sitting at its max height.

He's just trying to burn energy because a negative rate means he's getting paid to use it.

So sure - it's great to give that energy a functional use first (ex - charge his batteries) but eventually he runs out of functional ways to use the energy but could still be making money by using it.

Enter the desire for a dummy load.

Pumped hydro could do that if they had a way to bypass (either physically or electrically) their turbines on the downhill portion of the loop. Just pump water up and back down without extracting the energy. Then you have a dummy load that isn't just a power sink and is already designed to handle the relatively rapid switches on and off.

Yeah, but dummy loads are cheap. Probably cheaper than changing any designs in other places.

It's straight forward to add a giant resistive load that just converts electricity back to heat.

I can get 10kw heaters for just a couple hundred bucks or 1.5kw heaters for literally $20 usd. And that also switches on/off easily.

For hydro... just boiling water with a heater is going to be pretty much unbeatable if we're playing the "waste energy" game. No need to approximate it slowly with your pump motor and risk other infrastructure.

The idea was to have dual use so that they're not obsoleted when we get around to installing sufficient power storage for renewables and also a less heat intensive way to do it too.

The power is coming from energy that's otherwise going to heat the planet regardless (solar rays).

If you really wanted to be clever, your best bet would probably be to turn it into a laser beam and send it back to space. Would mimic that energy getting reflected instead of absorbed, albeit through a pretty inefficient and convoluted process.

Might make more sense to run carbon capture devices at that point, but again - in either of these cases we're back into the "it's getting pretty expensive to waste this energy" spot.

Giant resistors cooled with fans are cheaper and easier to maintain than pipes and pumps.

That is what (diesel powered) locomotives do to get rid of electrical power created by using the wheel motors for braking.

New designs store the power in batteries, but most locomotives used in the US still have a compartment filled with fans and resistors instead.

Yes of course. My idea was a way for existing facilities to also function in this capacity so you didn't wind up with facilities reliant only on negative prices. I think that's important because those prices are a bandaid on the real problem that would be solved by sufficient power storage.

You can build this at a small scale pretty cheaply but the connection to sink meaningful amounts of power would quickly become a significant part of the expense.

>"dummy load"

You mean crypto miner.

Surprisingly, not always.

If I buy a device for $100 that, given free electricity, will mine $500 of cryptocurrency in its useful life - I can easily lose money if I run it less than 20% of the time.

And I doubt electricity is negative priced >20% of the time.

Yeah, there are a ton of plans in this thread for what to do with excess energy. The problem is, that’s the wrong question. The goal is to answer the question “what should we do with excess energy where we don’t mind building the capacity, but then only rarely running it.”

Rather than coming up with some grand scheme, maybe it would be good if our dishwashers and washing machines could listen to the grid and activate when power cost was negative. (We may need to coordinate a bit though, so we don’t all activate at once).

I have an electricity contract with dynamic pricing that changes every hour based on the day-ahead electricity market for Belgium. I know what the prices for the next day will be around 13h10. I charge the car whenever the prices are lowest: around noon in the sunny months, at night during winter, preferably weekends. I save around 25% of my electricity bill like this. (More in summer, less in winter.)

So it's already possible to incentivize people correctly with price signals, at least in some regions of the world. But people are not yet familiar with this. I guess that will change as the pricing between dynamic and traditional contracts keeps diverging. With a traditional contract, you are essentially paying the average evening peak price all the time. With a dynamic contract, you get access to the cheaper and even negative rates.

In some areas negative prices account for up to 25% of hours so it's a decent number but still a rough number of spins up and down and a lowish duty cycle. A solution might be to build battery capacity along side these loads to effectively buffer the negative cost power to be able to run continuously. That would skyrocket the initial capital investment though.

Yeah, batteries are just the sort of expensive/straightforward solution.

If you think of it, a dryer is sort of a combination of a flywheel and a heating element, so it should be the over-provisioner’s best friend. IMO a real failure has been not taking advantage of our appliances.

The issue there is connectivity and most residential customers don't pay spot prices so you need to upgrade their meters as well or build metering into the appliance so they can get credit for the energy they burn off. Plus you're looking at putting a lot of extra cycles on equipment not built as well as it used to be so you're burning the useful life of a hard to repair device and probably not getting paid enough to cover that, plus they more and more designed to burn as little energy as possible.

I know there are some places where this happens though but it's more along the lines of the devices delaying their start until energy is cheap rather than being used as loads to shed excess capacity afaik.

> I know there are some places where this happens though but it's more along the lines of the devices delaying their start until energy is cheap rather than being used as loads to shed excess capacity afaik.

This is what I meant, sorry for the ambiguity. Load the washer up and kick it off whenever energy is cheap. I don’t care when it happens other than, like, that it happens once a day, so why not defer this to the power company, right?

Like I said support isn't really there for a lot of electric customers. I pay a single flat rate for electricity so there's no point in time shifting consumption.

Also there are downsides to having clothes just sit there for hours potentially before you dry them. They can get pretty dank from the moisture and for dryers some clothes need to be removed immediately when the cycle finishes.

Not all crypto mining requires dedicated hardware. I'm sure plenty of datacenters would jump. I know at least one instance where certain internal use autoscaling groups increase in size with lowering electricity prices (AI training, batch Hadoop jobs, and the like) to reap the benefits. With negative prices it'd just be bounded by the total capacity.

Presumably the negatively priced energy came from solar panels, so those sun rays were going to heat the planet anyway. The same still happens with a dummy load, just with extra steps in between to convert to and from electricity.

With enough solar panels deployed, you could still argue that they change the albedo of the Earth and therefore it's temperature.

Related, do Solar PV panels need any extra equipment to curtail instead of feeding into the grid?

Aside from software integration to remotely control household PV systems, is there anything else needed to curtail during negative price events?

If the inverter is smart enough, nothing else would be necessary

Thanks! Google managed to find more details on Reddit when I searched now

https://www.reddit.com/r/energy/comments/1iu2kkz/solar_curta...

Not necessarily. There's also reflection involved.

Now to figure out how much exactly you need to take into account the solar panel absorption spectrum & the albedo of the earth.

Could we use it for some kind of carbon capture process?

I think it's pretty clear with the constantly increasing durations of negative prices, so far we haven't found a way to do so profitably. Carbon capture or anything else for that matter.

Anything that would really love free energy also cost a lot to build and maintain/operate besides electricity. So much that a few hundred hours of free (or even better than free) energy a year is far from enough when you need >90% uptime to make sense. Maybe it makes you go from 95 to 85%, but still clearly it's far more than there are sunshine hours.

It's basically the idea behind things like hydrogen electroysis with excess energy.

The problem is that things that can use bulk energy productively like electrolysers, hydrocarbon crackers, smelters, AI training farms, etc. are very expensive and having them on warm standby but idle most of the time waiting for good grid weather makes for bad returns on the capital expenditure and operational costs.

I know this is grossly pedantic, but not matter what that electricity is used for, it will end up "heating up the planet a bit more". Energy is a waterfall whose base is heat.

Fossil fuels contain energy that are not in the form of heat, so electricity from fossil fuels would heat the planet even ignoring greenhouse effect. If from renewables, however, the energy has been previously extracted from the environment, thus being neutral in terms of heating the planet.

Not that it matters, because the effect would be miniscule in any case.

I did some napkin math and the amount of energy used from burning buried coal and oil since the industrial revolution began would warm the atmosphere about 3 degrees C. The assumption that all of the energy would be dumped into the atmosphere and stay there is obviously deeply flawed, but the overall effect might not be miniscule.

Technically if you power a laser shooting into space with solar panels you are cooling the planet, but you are ofcourse right in practice and on the scale of the universe!

That sounds like a good way to waste tons of energy during negative electricity prices to me! Shoot it into space.