The simplest energy storage solution is your hot water heater. Turning on everyone's hot water heater when there is surplus electricity, and turning them off when there's a deficit, is a very low cost solution.
The next level is using residential HVAC systems the same way. Comfortable temperatures are a range, so heating/cooling can push the temps to one end of the range, and when there is less electricity available, they can drift to the other end.
The charger for your electric car is another very practical sink for cheap electricity.
This is accomplished by having a spot price for electricity, and then people buying thermostats that query the spot price and turn HVAC, hot water heater, car battery chargers, etc., on and off.
This can be extended EVEN FURTHER by heating/cooling a pile of rocks to later use to heat/cool the house.
A battery consisting of a pile of rocks can't be expensive.
The idea is to not only adjust supply to the demand, but to shape the demand to the supply.
I am utterly astonished that this is never, ever discussed when talking about solutions to fluctuating supply. Having fixed electricity rates 24/7 is simply madness in today's electricity generation situation.
Where I live the vast majority of heat is produced by natural gas or propane. This includes water boilers, water heaters, clothes dryers, cooking ranges and ovens.
I bet the air conditioner isn't!
Besides, if you could buy an electric water heater that runs when electricity is mostly free, wouldn't you replace your gas heater? I would.
I would consider purchasing an electric boiler if the average operating cost was significantly lower.
Eventually this will make sense, but it’s not something that will happen in my neck of the woods in the next 20 years.
With fixed 24/7 electric rates, it will never happen.
Here in Flanders (60% of Belgium in terms of population) that is not an option. No more pure natural gas heating allowed in new construction from 2023. Gas/heat pump hybrids can still be installed until 2025, but that's it.
It's more strict for oil based heating. Even replacing an existing system is not allowed anymore from 2022.
You highlight the biggest problem: humans simply must change/adjust/whatever you want to call it, if humanity is to survive. The only technological out is fusion power. Without that, humans must learn to do with less (of everything). Everything else is empty rhetoric and time wasted.
Or increase the production of batteries (and solar/wind).
Is building nuclear power faster than building Lithium Battery Factories?
No that's wrong. There are plenty of ways of achieving carbon neutral energy production. Fusion is one of them, but it's unlikely that fusion will be a particularly cheap source of power.
Or we could use fission instead of fusion? We already have examples of countries using it successfully: France, Sweden, South Korea, and increasingly China. And the US during the 60s and 70s.
Geographically independent power, no carbon emissions, and no intermittency. It fulfills anything we'd get from fusion, except we have 70 years of experience using it in our power grids.
This doesn't really work in a lot of places in the world, because the base things are already too expensive. Most of the world does not have HVAC at home. They don't generate heat with electricity either. Car battery chargers only matter if you own an electric car, own a house and have a charger at home. None of this is relevant to most people in the world. It might be in a couple of decades, but not yet. And this includes France.
> The idea is to not only adjust supply to the demand, but to shape the demand to the supply.
This is completely backwards. Demand is highly price inelastic and inversely correlated with the supply of renewables. People usually eat at night. They heat their homes overnight. None of these things will change based on energy prices.
What you're proposing is a tax on the poor, and no practical benefit to boot.
> The charger for your electric car is another very practical sink for cheap electricity.
I don't have an electric car. I do not know anybody with an electric car. And wouldn't the surplus show up specifically when those cars aren't at the home?
> A battery consisting of a pile of rocks can't be expensive.
No, but the labor cost of hooking up your pile of rocks battery will be impractical for almost everyone.
> The next level is using residential HVAC systems the same way.
Again, I don't know anybody with an HVAC system. Everything here in the UK is based on natural gas and would cost an unbelievable amount of money to replace with electric.
Yeah, lots of things sound like perfectly great ideas until you actually run the numbers and find out they're hopelessly inadequate.
And electric cars actually tend to get charged at night, while people sleep, when solar isn't generating.
> electric cars actually tend to get charged at night, while people sleep, when solar isn't generating.
Because there's no incentive to do otherwise. Of course people don't time shift their electric use when there's no incentive to.
The only way most people can time-shift charging their electric cars to the daytime is if their parking spot at their job has a charging station. Practically, that means a very large fraction of office building parking spots will need charging stations. That sounds prohibitively expensive. Incentives can only nudge so far before you run into genuine problems of logistics.
Much cheaper than nuclear
Building charging stations isn't that expensive, definitely not prohibitively so.
charging stations for building parking don't need to be high speed, so the cost is just putting in an outlet (probably a 240 volt one)
Charging stations can be installed and can make money by charging the commuters to charge their cars while they work. If the price differential between day & night is enough, it will be worthwhile for both the parking lot owner and the car owner.
Smart appliances are a good idea in principle but rolling them out will take a long time. Water heaters last 10+ years. I don't think there are even any widely available on the market today which will automatically increase the temperature at mid day in anticipation of an electricity shortage later. And it's a safety hazard in homes with small children; hot water temperature should never be hot enough to cause burns when someone turns on the faucet.
Most homes don't have enough free space for a big pile of rocks to increase thermal mass. My home has pretty good insulation but on hot days we're going to be miserable without AC in the evening regardless of how much we chilled the house down earlier.
> Water heaters last 10+ years.
Again, we're just talking the thermostat for it.
> I don't think there are even any widely available on the market today which will automatically increase the temperature at mid day in anticipation of an electricity shortage later.
Why should there be? Electric rates are fixed 24/7. All the power company has to do is provide an API to get the spot price, and start varying the electric rates according to supply. The market will adapt.
> Most homes don't have enough free space for a big pile of rocks to increase thermal mass.
Criminy. Do I have to design it, too? Most homes have a basement or a crawl space.
Those sound like cost savers, not the mass storage solution that is needed. I haven't done the math but I bet you're missing about an order of magnitude of storage needed to make intermittent power sources sufficient to power the grid by themselves.
> by themselves
Even if it is only 10%, that's 10% less grid storage batteries needed.
Ya know, car engine efficiency has improved dramatically over the last 50 years. Each specific improvement was small - but the aggregate adds up.
To some degree, a power saving feature for hot water cyclinders in NZ has been used since at least my grandparents time.
https://www.eeca.govt.nz/assets/EECA-Resources/Research-papers-guides/Ripple-Control-of-Hot-Water-in-New-Zealand.pdf https://www.eeca.govt.nz/assets/EECA-Resources/Research-pape...
The problem with your great ideas, and "great ideas"generally is the lack of proven numbers.
As the poster above you pointed out the capacity of LI batteries is tiny. Yet you tout car batteries as though that were a new idea and a meaningful solution. And you ignore the fact that if you use car batteries as storage for the grid, that detracts from their use to, you know, run cars.
You also ignore the losses from your solutions. What is the round trip loss from heating up rocks and getting the energy back? It is huge. And you artfully forgot to mention all the equipment needed to get the energy back out in usable form such as electricity.
All the books and studies talk about load shaping, contrary to your "astonishment" that no-one is considering this "brilliant idea". The problems with load shaping are many. If you shut a factory down to spare the grid, then it is not producing. So all else being equal, you need more factories for the same production. Building and maintaining those extra factories takes labor, management, and energy.
Getting people to turn off air conditioning means that they are less comfortable, or perhaps unable to sleep, or unable to work. The South of the US more or less became viable economically due to air conditioning.
This is not unique to you, but I am really fed up with people spouting half-assed ideas and thinking that they constitute a solution.
As they said in the dot.com era - ideas are cheap.
Disclaimer: Founder of Electric Foundation (accelerate EV adoption), Conduit Foundation (require all new construction to be EV ready)
> And you ignore the fact that if you use car batteries as storage for the grid, that detracts from their use to, you know, run cars.
Most people drive about 20 - 40 minutes per day. In large cities, it is 2+ hours. The remaining 22 hours, EV is an energy sponge. Take the current peak load, produce more renewables than the peak, turn renewables to 11, absorb all the excess free energy. EV is primarily an energy storage device, some people take trips on them once in a while. None of this energy is wasted. There is no need to think of a round trip for this scenario. All energy for transportation can be free and clean, we are capturing excess production. Utilities are curtailing renewable production, this is a shame, we have built solar/wind farms, but not using free energy! This is a huge barrier for new renewables, producers have to consider growing curtailment.
> All the books and studies talk about load shaping, contrary to your "astonishment" that no-one is considering this "brilliant idea". The problems with load shaping are many.
Utilities are a monopoly, guaranteed a cost + profit formula. Utilities increase their costs to increase the profit. We see the same formula play out in health care, hospitals charge $1,400 for a band-aid. Energy can be a lot cheaper, and zero. It is entirely possible for Utilities to pay us for using our electric cars storage, they provide the best grid stabilization and smooth out demand and supply curve, flattening the peak rates. Instead of paying 10 - 20x for peaker gas plants, why can’t Americans be paid? There is a nexus of Utilities (generators, producers, distributors) and jacking up capital costs.
> All the books and studies talk about load shaping, contrary to your "astonishment" that no-one is considering this "brilliant idea".
Because these are produced by the utilities. Economists and scientists are funded by the industry to write their view. This happened and continues to happen. [1]
Lead is a gift of God. [2], this view was supported by scientists, surgeon general, AMA, public health and nearly all Govt bodies. Industry sets the rules for all of us so they can continue to extract profits for as long as possible. With this rule, we are all poisoned by lead for ~100 years. Lead poisoning is permanent! "lead does not break down over time. It does not vaporize, and it never disappears. modern man’s lead exposure is 300 to 500 times" [4]. We not only have polluted ourselves, but made a permanent toxic change for all of humanity. For what? To make the richest people a little bit richer?
Koheo's rule (put in place by the industry) was used and continues to be used for thousands of other toxins.
"Using the Kehoe Rule, Ethyl Corporation was a winner in either situation: if its product was actually safe, Ethyl would be seen as a responsible party. If, however, its product was unsafe, it would take decades to demonstrate that with certainty. The process of getting to certainty could be prolonged by challenging the methods and results and calling for more data, and while it was going on the product would continue to generate profits. Kitman indicates that the strategy taken by the lead industry, referring to use of the Kehoe Rule, similarly "provided a model for the asbestos, tobacco, pesticide and nuclear power industries, and other(s)... for evading clear evidence that their products are harmful by hiding behind the mantle of scientific uncertainty."[4] Kettering Laboratories under Kehoe's leadership also certified the safety of the fluorinated refrigerant, Freon, "another environmentally insensitive GM patent that would earn hundreds of millions before it was outlawed."" [3]
Innocent until proven guilty is for people. Should we use the same rule for stuff that harms us? How can we prove this harm when all the studies on harm are done only by the insiders?
The internet that we see today, all the things that are happening in the tech space directly result from the breaking up of AT&T monopoly. We went from circuit switched to packet switched networks, built the underlying networks to throw packets at each other."AT&T, a powerful gatekeeper, controlled innovation by controlling access to the resources needed to innovate – the wires – the physical layer of the telephone network. AT&T's view of Paul Baran's packet-switching design was: ‘It can't possibly work, and if it did, damned if we are going to allow the creation of a competitor to ourselves.’ [5]
The current configuration of the grid is a creation of this utility nexus. We must break this monopoly. If we can figure out how to sling IP packets at each other, surely we can imagine a reconfiguration of the grid that will let us throw electrons at each other. This will result in upto a thousand dollars/month saved for all of us (residential use), as well as making all the energy clean and renewable. Forever.
---
[1] https://thereader.mitpress.mit.edu/industry-weaponizing-science-agenda/ https://thereader.mitpress.mit.edu/industry-weaponizing-scie...
[2] https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.75.4.344 https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.75.4....
https://en.wikipedia.org/wiki/Robert_A._Kehoe https://en.wikipedia.org/wiki/Robert_A._Kehoe
[3] https://www.edf.org/sites/default/files/the-hour-of-lead.pdf https://www.edf.org/sites/default/files/the-hour-of-lead.pdf
[5] ATT and packet switched networks: https://www.open.edu/openlearncreate/mod/oucontent/view.php?id=13363§ion=3.10 https://www.open.edu/openlearncreate/mod/oucontent/view.php?...
[4] https://www.typeinvestigations.org/investigation/2000/03/02/secret-history-lead/ https://www.typeinvestigations.org/investigation/2000/03/02/...
"Lead is poison, a potent neurotoxin whose sickening and deadly effects have been known for nearly 3,000 years and written about by historical figures from the Greek poet and physician Nikander and the Roman architect Vitruvius to Benjamin Franklin. Odorless, colorless and tasteless, lead can be detected only through chemical analysis. Unlike such carcinogens and killers as pesticides, most chemicals, waste oils and even radioactive materials, lead does not break down over time. It does not vaporize, and it never disappears.
For this reason, most of the estimated 7 million tons of lead burned in gasoline in the United States in the twentieth century remains–in the soil, air and water and in the bodies of living organisms. Worldwide, it is estimated that modern man’s lead exposure is 300 to 500 times greater than background or natural levels. Indeed, a 1983 report by Britain’s Royal Commission on Environmental Pollution concluded that lead was dispersed so widely by man in the twentieth century that “it is doubtful whether any part of the earth’s surface or any form of life remains uncontaminated by anthropogenic [man-made] lead.”
(edit: formatting)
Good points.
Denmark has a lot HVAC district heating with storage for load balancing planned in it's energy strategy 2050 (as I remember when I read it few years back).
Example of a proof of concept for electricity to heat and reverse via rock heating is the Siemens Gamesas Hamburg plant:
https://www.siemensgamesa.com/explore/innovations/energy-storage-on-the-rise https://www.siemensgamesa.com/explore/innovations/energy-sto...
Additionally, I would add that there electricity for generation of hydrogen or synth fuels for airline or seafaring industries:
https://www.offshorewind.biz/2021/05/17/construction-starts-on-orsteds-first-green-hydrogen-project/ https://www.offshorewind.biz/2021/05/17/construction-starts-...
https://fuelcellsworks.com/news/major-green-hydrogen-facility-planned-for-denmark/ https://fuelcellsworks.com/news/major-green-hydrogen-facilit...
> I am utterly astonished that this is never, ever discussed when talking about solutions to fluctuating supply. Having fixed electricity rates 24/7 is simply madness in today's electricity generation situation.
In many areas wholesale markets work on a spot price basis (although players in the market can of course hedge against low/high prices), but consumers have been very reluctant to go with spot price contracts.
This will probably not be helped by the experience of those consumers in Texas who got $10000 electricity bills during last winter's storm, as the prices skyrocketed.
> A battery consisting of a pile of rocks can't be expensive.
> The idea is to not only adjust supply to the demand, but to shape the demand to the supply.
> I am utterly astonished that this is never, ever discussed when talking about solutions to fluctuating supply. Having fixed electricity rates 24/7 is simply madness in today's electricity generation situation.
It might not be the same everywhere but in France and Belgium at least, it is very common to have two rates: peak and off-peak. A signal is sent by the provider to your electrical meter (basically 220V when off-peak, 0V when peak) that can pilot a switch that turns the hot water heater on only during off-peak hours.
Some electric heaters also work on that principle, they are filled with bricks and heat up during off-peak hours then release the stored heat later, when it is needed. That's your "battery consisting of a pile of rock". However, I have lived with those things and it doesn't work at all because storing heat in anything else than water just doesn't work well. Basically at the end of the day, when you come back from work and need the heat that was stored during the night, it's already gone (and totally wasted as the house was empty). The most modern designs don't work much better. I think these only still exist because the idea seems good enough to convince people to buy them, but it's not actually technically feasible.
Anyway, everything you say is already possible in western Europe, and already done (except for HVAC, but that's mostly because HVAC in private homes isn't very common in the first place). What could be improved is to have more dynamic off-peak hours, but that's not a technical problem, everything would already work as is.
I think the problem with storing energy in western Europe, is that you need most energy for heating in winter, when there is hardly any solar power. So any convenient daily pattern doesn't work. For wind, you can probably heat up during the night assuming there is less other demand for electricity.
However, that doesn't help during period when there is hardly any wind. It is not as if you can stop heating your house for a couple of weeks.
I'm curious have this will play out. On a bright summer day, there is plenty of solar power. So it make sense to do everything during the day. During winter, it is better to distribute the load and move load to the night. That requires quite a bit of signaling to get right.
>>"The simplest energy storage solution is your hot water heater. Turning on everyone's hot water heater when there is surplus electricity,"
I already do this manually. I unplug it before taking a shower and plug it again at night. Of course, doing it automatically is the only way is going to be done at scale.
> The simplest energy storage solution is your hot water heater. Turning on everyone's hot water heater when there is surplus electricity, and turning them off when there's a deficit, is a very low cost solution.
This is available in the UK, using a thing called the Economy 7 tariff on electricity [1]. You have two sets of circuits on this plan. One set is the normal set that provides electricity 24/7, so you get expensive electricity when the rate is high and cheap electricity when the rate is low. The other only provides electricity when the rate is lower, such as at night (the 7 in "Economy 7" refers to 7 hours of cheap electricity at night).
There are water heaters designed specifically to work with this [2]. They have a main heating element that does most of the work, which you connect to a circuit that only provides power when the rate is low. These tanks also have a boost heating element that is on a 24/7 circuit meant to just provide any extra heating you need for hot water use during the day.
They also have tariffs that provide a fixed rate 24/7, which should be cheaper than Economy 7 during the day but more expensive at night, so whether Economy 7 saves you money depends on how much of your electricity use is at night.
[1] https://en.wikipedia.org/wiki/Economy_7 https://en.wikipedia.org/wiki/Economy_7
[2] https://www.cse.org.uk/advice/advice-and-support/economy-7 https://www.cse.org.uk/advice/advice-and-support/economy-7
That has a significant risk, what if you hit the end of your range whilst the deficit is still getting worse? Deficits are not following nice predictable normal curves.
I've lived somewhere with storage heaters. They are horrible, practically indistinguishable from no heating at all. A large enough thermal mass would require a complete rebuild.
> what if you hit the end of your range whilst the deficit is still getting worse?
You, the consumer, can override it. You get to decide between donning a sweater or paying more. Isn't that objectively better than some bureaucrat simply turning off the power to your neighborhood (rolling blackouts)?
>I am utterly astonished that this is never, ever discussed when talking about solutions to fluctuating supply.
I'm not surprised to be honest. On a forum like this, you'll get a bunch of very smart people talking about something they don't know a lot about, but authoritatively. (Just look at the incredibly snarky and dismissive responses you've received)
It's certainly talked about in industry and work is going into implementing it.
I work in the electricity-tech industry but I've given up on trying to talk about things like demand response as I'm always shouted down
HN has also snarkily informed me many times that demand for gasoline is completely inelastic.
Never mind that the pump price of gas changes every day, especially when there's an oil refinery explosion, or glut, or whatever. It's a classic example of demand shaping via price. And it works because demand for gas is elastic.
The only time this did not work was when the government regulated oil prices and which stations got a gas allocation. Older folks like me might remember this - long gas lines in the 1970s. Gas lines that disappeared literally overnight when Reagan repealed the price and allocation controls.
How is a refinery explosion, pipeline shutdown or glut proof that demand is elastic?
All that shows is that supply is elastic and that market price varies. For the most part, demand is inelastic. You require the same amount of fuel to go to work/school and return. Now you could vary your shopping habits, go to a shopping center with several stores as opposed to the stores you like. You could put off a road trip or vacation but it isn't like either of those things are the bulk of gasoline usage.
Refinery and pipeline problems are relatively short-term events. Something like an embargo which caused the oil crisis would definitely change behavior and demand.
When you talk about allowing prices to determine who gets and doesn't get a good that is fine when it is a luxury item like graphics cards. But when you talk about the same thing for a necessity like food, water and electricity then getting priced out of the market means death.
The thing is, the industry of your country doesn't turn off many factories, even during night. They suck juice.
Also, for shops, mall, offices, there is a prolongued pic during the day, and you can't offset that.
Also, your solution assume:
- a lot of smart connected systems (for the heating, the washing machines, etc)
- massive EV parks
- rétrofit buildings to fit those big rocks, heat them, and get heat from them
This is not trivial and would add to the cost to sell renewable energies, which are already not easy to market.
My water heater is not a storage device for electricy. It lacks the means to recover energy from it, and I want hot water in the morning, every morning, not at random times during the year when there is a surplus of power.
Also, in any cold climate, 'surplus of energy' is generally associated with the presence of sunlight, i.e. at times when heating the house is typically not a great priority. You want that heating on when it is coldest, which typically coincides with the lowest renewable energy production as well.
Charging and decharging your car sounds great, but it means your battery is deteriorating while you aren't even driving.
Your water heater quite probably is an electrical storage device, it's been a fairly standard tech for decades in many countries, often using cheap coal or nuclear power at night since they aren't economic to ramp down.
I'd be very surprised if France didn't do things like this. edit: googled it:
https://thegoodlifefrance.com/french-hot-water-tanks-tarrifs/ https://thegoodlifefrance.com/french-hot-water-tanks-tarrifs...
So, one of the "unacceptable" solutions to fighting climate change, is something that countries with the highest nuclear mix have been doing for ages.
I'm quite sure my water heater does not store electricity. It stores hot water, and it completely lacks the ability to turn hot water back into electricity. At best I can use electricity at surplus times to heat water more cheaply, but that doesn't make it 'an electrical storage device'. I cannot attach a light bulb to it, for example, so you cannot use it during dark, quiet days to compensate for the lack of renewable power.
I work at a company that does DERMS projects in this space (peak shaving, load balancing, power factor optimization, voltage support, etc, etc).
It's not that no one talks about this stuff, it's just that it's as with all things in the utility space projects take time and a lot of the work being done is still exploratory.
No one I work with seems to think this stuff is a magic bullet either, just part of the solution (of which nuclear is another important part).
I should also note that these DERMS projects are very software reliant and I think all of us here on HN know quite well that reliability can be an issue in the software space...
I wonder how recharging the net from a plugged in e-car would affect the lifetime/resale-value of that car, if that concept would be in general use. And how the grid then would develop, regarding overall capacity.
NIMBY as in NOT IN MY BATTERY! :-)
I live in an area where hot water heating is common. Hot water heaters have secondary loops through the main oil-fired boiler and these could easily be made electric.
A missing link is indeed a cinder block energy storage pile that could be set to preheat water going into the hot water boiler, or to cycle through water going into heating.
Trouble is, it's nowhere near enough. Cases you mentioned (charging personal cars, heating/cooling down houses) are relatively small. Let's be generous and say it's 20% of overall energy consumption. For comparison, last summer average energy production of UK's offshore wind stayed under 10% of its capacity for a month. How do you even make a dent in this massive sea of missing energy with those small and temporary reductions?