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Comment by WalterBright | Hacker News Reader

By far the most efficient grid "battery" to reconcile fluctuations in demand & supply is to have a realtime price for electricity. Water heaters, for example, can be equipped with an internet device (at last, a reason for an internet connected water heater!) to monitor the price of electricity and shut off the heater during price spikes.

Some "batteries":

1. hot water heater

2. HVAC system

3. EV charging

4. Some lights (like yard lights) can be dimmed or shut off during rate spikes

5. Same for street lighting

6. Computers can switch to low power mode

7. Refrigerators

8. Dryers

This is far better than the "rolling blackout" bureaucratic solution.

Note that the pump price of gas varies daily. This is the market reconciling constantly shifting supply & demand, and it works great.

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I work for an oil and gas company and I’m working on a project to turn our pumps on and off based on spot price, since we pay wholesale 15-minute price for electricity. There’s a huge untapped benefit to aligning incentives between electricity consumers and producers.

Hooray! Someone finally gets it!

Frankly, this is a stupidly obvious idea, and in retrospect we'll all be baffled why this wasn't routine years ago.

Enron made the utilities pretty skittish with regards to market-based pricing.

https://www.youtube.com/watch?v=9ejzBYus8qE

The problem that Enron capitalized on was:

1. Consumer electric rates were set by law

2. Utilities were obliged by law to provide whatever electricity consumers demanded at that rate

This meant that utilities had no choice but pay whatever Enron demanded and resell to consumers at a massive loss. This ridiculous catastrophe was entirely a construction of the electric regulatory framework.

It doesn't have any resemblance to what I proposed. What I propose is more akin to how gas pump prices vary every day. Note that there are no laws setting the price or distribution of gas. When there were (back in the 70's) the result was LOOOONG gas lines. The Enron fiasco and the gas line fiasco are prime examples of what happens when government tries to centrally plan pricing and distribution.

Not really: the Enron fiasco happened because the government reduced its involvement, deregulating the power grid, and gave actors like Enron, Duke Energy and others the ability to manipulate the market, causing prices to swing wildly. California saw an 800% increase in wholesale energy prices. You object that the retail rates were set by law. But consumers could not handle that 800% increase; most people can't handle an unexpected expense of a few hundred dollars. Utilities weren't obliged to provide power when things went to hell, they imposed rolling blackouts. They had to.

With gasoline, you can wait and shop around; if a station tries to gouge you you can see if you can get a lower price down the block. The power grid has to be balanced on a continuous basis, and if it's out of balance, the grid operator has to obtain power immediately.

The power grid requires careful management. Call that "regulation" if you like, but it isn't optional.

California did indeed deregulate wholesale electricity prices, but not consumer prices. Rolling blackouts are a form of rationing, rationing results from shortages, and shortages are the result of price fixing by by the government.

Note that Reagan's first act as President was to repeal all oil and gas price and distribution controls, and the gas lines evaporated literally overnight. Yes, I was there and remember it :-) We've had a number of oil crises since, but no gas lines.

> But consumers could not handle that 800% increase; most people can't handle an unexpected expense of a few hundred dollars

Many places that enable spot price electricity contacts for consumers have other kinds of contacts available too. Consumers who choose spot do it if they trust it's on average a win. There are also hybrid models where there is a price ceiling or other hedge.

The government may have reduced involvement in some areas, but IIRC, it also limited ownership of generation facilities by utilities.

“Any market reform, government initiative intended to reduce red tape and promote market forces will have the ultimate effect of increasing the total number of regulations, the total amount of paperwork, and the total number of bureaucrats the government employs.” — David Graeber

Many components of this approach are theoretically at work in a 'smart grid'. https://en.wikipedia.org/wiki/Smart_grid

The carbon lobby pummeled us with propaganda about how renewables "weren't ready" until batteries were good enough to fill in the gaps once they started becoming price competitive.

Ironically they were the ones who set up think tanks that preached putting faith in the market to solve our problems for us - at least until they started getting undercut.

Power related financial instruments are a pretty big market. People just don't know about it.

I should have patented it. I'd be a billionaire!

My previous firm (in Australia) attempted to do this for commercial buildings by monitoring the 5 minute wholesale electricity price from the National Electricity Market [0]. We installed current meters on each circuit in the buiding, HVAC, lighting etc. then were able to estimate cost savings for a given 30 or 15 minute period if that circuit was shut off. We even tried to estimate the savings if HVAC was e.g. reduced by 1 degree C in the building for a given time of day, occupancy, and weather conditions by using 1-2 years of 15-30 min resolution historical energy usage data for that building.

[0] - https://aemo.com.au/Energy-systems/Electricity/National-Elec...

The sick joke is we have far more clean energy than we would ever need.

We don’t need to live half our existence in “low power mode”, if we just made some simple rational decisions.

The city of Austin already does kind of a version of #2:

https://savings.austinenergy.com/rebates/residential/learn/m...

> What Is the Power Partner Program?

> The Power Partner Program is a community-wide coordination of air conditioning usage that allows Austin Energy to manage energy use during peak summer days when it matters the most.

> During a Power Partner event Austin Energy will adjust the temperature setting on your Internet-connected thermostat. Temperature adjustments up to four degrees reduce usage when the energy and cost savings are needed the most community-wide, yet do not significantly impact comfort.

It's not market-based in the way you're talking about (real-time price being pushed through to the consumer), but it may be market-based in a different way. The same page goes on to say it "helps lower the overall cost of electricity in the community". So I assume the utility uses it to reduce how much electricity it has to buy at peak prices.

It's a clumsy attempt to emulate what a market does. One telltale aspect of its clumsiness is the elastic use is confined to the A/C (I listed other avenues). A market based solution would use price, and let the consumer find the best way to adapt to it.

Another complicated bit of clumsy silliness is cap-and-trade. The straightforward way is just tax the carbon.

I had something similar offered by Duke Energy. They credited like $10/mo to be able to turn my AC off whenever they felt like it. It was terrible. You know when i want my AC the most? When its hot. And that is exactly when it would be disabled. That thing got removed within days.

Turning off is a blunt instrument. A better approach is to set the thermostat higher.

It has the same effect. Its hot out. I want it not hot in my house.

There is already a very successful company here in Sweden, that is doing exactly that.

They do even much more than what you describe like providing electricity realtime from the best supplier depending on various factors like price and climate friendliness in a given time.

https://tibber.com/se/smart-elavtal

Another cool thing with Tibber is that they provide APIs to access your usage etc. THAT is something I would like to see from all general companies.

https://developer.tibber.com/docs/overview

> climate friendliness

That's good. This can be objectively determined with things like a tax on emitted pollution, which goes into the price of electricity provided, and then the utility can simply buy the cheapest.

Supply and demand is great, but calling it “battery” is a huuuge stretch. Batteries manage supply, pricing helps manage demand. You need both.

Gas prices at the pump is pretty bad example. Varying electricity prices are build on shifting demand by few hours. Gas prices are unpredictable and you cannot really shift demand much, and prices swings can last years.

Modulating demand by modulating the price won't solve the entire problem, but I bet it could reduce the size of needed grid batteries by a huge margin.

> calling it “battery”

I did put it in scare quotes, because although it is not an actual battery because it does not store/release charge, it serves the purpose of one.

There's a bacteria called Legionella that thrives between 60 and 120 degrees Fahrenheit. To prevent it from growing in the hot water supply, most water heaters shoot for 140 and then achieve cooler temperatures by mixing in cold water at the faucet.

Your plan could still work, but I think that the water heater is its best target, and that much of the savings goes away once you factor in that constraint.

I think that there are many opportunities to improve by thinking along those lines though. For instance, I always thought it was weird that the grocery store I worked at ran the refrigerator compressors even when it was cold outside.

For killing off the legionellas it's sufficent to heat the water tank to 140 once a week. The exact time could of course be chosen according to the currrent energy price.

Water should be heated using heat pump or other more efficient system. Also most of hot water is used in washing, you can recover a lot of that waste water heat back.

I had the same idea. Startup name is strata.energy. Pool pump s are another good one for your list. No one cares when the pump runs, just that it runs.

Literally decades ago we had a simple version of this. I think it was only for our pool pump...maybe the water heater. My understanding is my parents got some sort of fixed discount if the power company had the ability to periodically cut power. I'm not sure how the signal was sent, but I remember an electrician pointing out the wires. It was probably a small box next to the breaker.

In countries where big industry is gone the main demands become consumers, and so it becomes consumer loads on the grid that need to change to adapt to supply. That's more complicated than a few big industrial users being paid to turn off equipment. There's many more stakeholders to coordinate.

> many more stakeholders to coordinate

That's the beauty of using price as a signal. People's self interest does the rest.

Markets are far too complex to be coordinated by central planning.

There used to be an electricity tariff in the UK called Economy7 which was a simplistic version of this. Valid during night hours, you could, eg, recharge storage heaters with it, for release during the day.

Not sure if it is still available.

Edit: it is, but requires special meters at the premises.

Great, Enron all over again, with speculation sharks telling powerplants to shut down in brownouts to manipulate the price.

Man. This smells of techie overkill. The utility can make an announcement via radio or broadcast or sms to let you know if the supply is under pressure. Then switch off non essential appliances normally.

I live in a country with a struggling national power grid as people have come online faster than the utility could service old and build new powerstations. The blackouts or load shedding are not as frequent as a decade ago but we've learned to live energy cheap.

Peak and off-peak pricing already exists in many places. Power consumption naturally fluctuates pretty wildly. It is very difficult to make any large scale system that is highly efficient at both 100% capacity and 50% capacity.

FERC 2222 will go a long way towards allowing these to be aggregated into virtual power plants.

> can be equipped with an internet device

I don't know how efficient a houseful of IOTs can be, but I don't want one.

Second question: what's to keep my neighbor(s) from ignoring efficiency in favor of demand. So I'm doing without lights while they party on. (Please don't say regulations.)

Nothing's supposed to stop them, they just pay more. That's the bloody point.

> I don't know how efficient a houseful of IOTs can be

The Nest thermostats come to mind.

> what's to keep my neighbor(s) from ignoring efficiency in favor of demand

He gets to pay the price for it. It's the same thing that prevents him from buying fuel guzzling cars. (Note that sales of guzzlers inversely track pump gas prices.)

Price fixing by the government has the perverse effect of continually causing demand to outstrip supply - rolling blackouts, shortages, rationing, etc.

Heating water with electricity is the literally last thing we should do. That is, once clean electric energy is cheap, we can do it. But we are not there yet. Hence we should at least use heat pumps or similar technology.

Heat pump is heating water with electricity... And it’s not the last thing we should do, it’s economical today if you live in a mild climate. I installed one in my house a year ago. The initial cost was ~$500 over a similar gas water heater but it qualified for a $1000 rebate making it cheaper than a gas unit. Cost of heating is less than I used to pay for an old gas water heater. It might not make sense in a region with cold winters, but in a moderate region they make a lot of sense.

In a heat pump, the heat does not come from the electricity but from an environmental source. The electricity moves and compresses but does not heat anything.

Your usage of dollars indicates you live in the US. I hate to tell you but your definition of "economic" is probably not sustainable. Your price of electricity would probably double or even triple when switching to (cheap) renewables.

> Your price of electricity would probably double or even triple when switching to (cheap) renewables.

Finally someone who recognized that renewables are a magnitude more expensive instead of the usual "muh, renewables are cheaper!" fallacy. Look at the typical price per kWh in Germany (around 32ct/kWh) and tell me again how that is cheap...

I was talking with someone recently and they recently bought a new electric water heater. I asked why they didn't go with a heat pump option, and they said the dealer told them that heat pump water heaters are basically a "robbing Peter to pay Paul" situation where you end up taking heat you would have added to your house and putting it in your water instead.

I guess in warm climates / seasons that is probably a net benefit, but I've noticed our electric co-op also promotes highly-insulated electric water heaters instead of heat pump water heaters.

Not sure what I think of it all. We have an electric water heater and at first I was grumpy about the relative cost to run relative to natural gas, but I've come to terms with it. It's about the simplest device possible, and that has some value I think.

A conventional heater can, at best, use 100% of the energy to heat both the water and the house.

A heat pump would use some of that energy to capture some more from a heat source (outside air, or geothermal, ground temperature). It gets less efficient as the heat source becomes cooler, so it might not be such a good idea in very cold climates. Theoretically, though, it shouldn't get lower than 100%, and efficiencies can reach 300% pretty easily.

I haven't done an extensive search on the topic, here is one of the first sources I found with the kind of graph I wanted: https://www.nordicghp.com/2017/01/heat-pump-effective-temper...

I read about 270% at -4°C (25°F). 1 watt of electricity in, 2.7 watts of heat out, not bad. The same graph reads about 480% at 18°C(65°F), and 150% at -20°C (-5°F). I know that gas heat pumps exist as well, and some systems are hybrid, so it sounds like a no brainer to me. On the flip side, they can be quite expensive, so do your calculations relative to the temperature history, and hourly electricity hours. It would be more efficient to heat when the air is warmer during the day (assuming air pump), and combine that with a well-insulated house.

Solar (thermal or electric) is pretty interesting too, I wonder what kind of efficiency one can get with photovoltaic + heat pump (photovoltaic is more versatile, being more useful during summer).

I think GP is talking about heat pump water heaters that are working between the air in the room where heater is installed and the hot water. Very different from what you are suggesting. It could still make sense if it is installed in a room with lots of waste heat, e.g. next to a clothes dryer and other appliances.

> I think GP is talking about heat pump water heaters that are working between the air in the room where heater is installed and the hot water.

Correct. Every heat pump water heater I've ever seen has the heat pump directly on top of the water tank. It's possible they make ones that tie into an external heat pump, but I've never seen one.

In Japan, separated heat pump unit / tank is pretty ubiquitous and never seen union unit.

https://echonet.jp/introduce_en/gz-000505/

Huh? That would indeed be pretty dumb. I would have at least expected a duct that pumps air from outside...

Heat pumps make little sense if you don't have access to a thermostatic source, or indeed any "free" heat source.

The trouble with water heaters is you want hot water year round. Heat pumps are pretty ineffective once you get down close to freezing. So having an exterior air source heat pump would only make sense for maybe half the year in a lot of locations.

Generally utility rooms in houses have a decent amount of waste heat anyway from being near the furnace, so it probably does work out decently a lot of the time.

My in-laws have a heat pump water heater and it makes their basement noticeably colder in the summer, which is pretty nice.

Err, what? The heat exchanger has to be outside the house of course! Who would even build that inside? That's crazy!

To counter that point, high-end tumble dryers are universally built with a heat pump that is all located inside the same room (it's even in the same device).

It's because they are cooling air to dehumidify it (the drying part), then they pump the heat back into the same air to circulate back into the wet clothes.

https://images.jifo.co/10180236_1567417620885.png

This is because a bunch of the units on the market source their heat from directly around the water heater (likely a conditioned area of your house). They have options for ducts to dump the cold air they generate outside during the winter, but this doesn't help as you then need to draw in outside air to make up the pressure differential (otherwise good luck opening doors).

Units that have the radiator/compressor outside are 3-5x the price, and are hard to find.

These "hard-to-find" units are pretty much the standard offering for heating new houses here in Germany. Where are you living?

Home heat pumps always have an exterior unit here. It's heat pump water heaters that don't [0].

[0] https://www.rheem.com/products/residential/water-heating/hyb...

The way the parent comment is worded, he is actually advocating for not doing activities like running hot water heaters during peak load times.

I know many utilities in my area have a program you can sign up for where they will cycle through the registered AC units to balance out peak load in the summer. I'm not entirely sure how they manage that, I suppose they have to have some sort of sensor switch they install in your circuit.

> you can sign up for where they will cycle through the registered AC units to balance out peak load in the summer

This is inefficiently attempting to solve the problem in the same way while trying to maintain that flat electric rate. We need to get past the idea that electric rates must be flat.

> We need to get past the idea that electric rates must be flat.

I'm not aware of anyone that does minute to minute electricity pricing, but I know for many utilities you can sign up for alternate price schedules that have different rates based on the time of day.

I would guess as much as anything it's a metering issue.

price schedules that have different rates based on the time of day.

That's better than 24/7 flat, but is not a solution for dealing with spikes in demand or fluctuations in supply. Minute-by-minute spot pricing is the solution for that. With the ubiquity of the internet, and low cost for IoT, it's feasible, practical, efficient, and effective.

Griddy (in Texas) offers 15-minute wholesale price for electricity.

How does this work? Where I'm at (Iowa) your electric provider is determined by where you live. As far as I know, you have one company that provides electric to your home. You don't have the option of picking someone else.

Based on the website it looks like Griddy is something you can just sign up for and then your bill will be routed through them somehow? How does that work? Who maintains the infrastructure?

The common term for this is “regulated electricity market” vs “deregulated electricity market”.

By your description it sounds you guys in Iowa have a regulated market. There you have a vertically integrated electric utility company who does everything from generation to line maintenance and billing with oversight from a public regulator.

In a deregulated electric market you have separate generator companies who sell wholesale electricity to retail energy suppliers who sell it on to end customers. Transmission companies maintain the grid infrastructure and they are paid by the other participants for this service. This scheme when it works right can result in more competition and thus better efficiencies.

This page seems to explain it quite nicely: https://infocastinc.com/market-insights/solar/regulated-dere...

Meanwhile, there are hot water heaters in use everywhere. That isn't going to change anytime soon. Besides, in many places during peak solar there isn't anyplace to dump the electricity. Electric hot water heaters can take care of that problem, as water will stay hot in one for a couple days (I know from experience).

A heat pump can approach 500% efficiency and is powered by outdoor ambient air (using direct heating as a fallback).

https://www.youtube.com/watch?v=-vU9x3dFMrU

It still uses electricity, and can be shut off during electric rate spikes, acting just like a "grid battery" without the expense.

> Heating water with electricity is the literally last thing we should do.

Would you consider electric showers an exception? They only heat whatever water you're using. I've lived in houses with no hot water in the taps for months, but could still take a hot shower whenever.

I think it was a reference to the way we get electricity.

Burn gas at the plant to heat water to run steam through turbine to get electricity ... and then use electricity to heat water again? Just use gas at the end point.

Getting heat from fuel (or sun) is easy and efficient. Converting it to electricity isn't.

If electricity comes from a non-fossil-fuel source - it is even more expensive/valuable.

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