[WalterBright]

> Imagine when your fridge can do this

I've been posting for years that an effective grid "battery" is internet connected refrigerators, water heaters, A/C, car chargers, etc., that only run when power is cheap, i.e. when solar/wind is providing excess power.

A great deal of our demand for electricity is elastic and shiftable, which will eliminate a huge chunk of the need for grid batteries.

Glad to see this finally gaining some traction!

[BurningFrog]

How much of energy consumption even is by households though?

I think people have a strong bias for thinking the things they see and touch during the day are environmentally important. But most "pollution"/energy use happen out of sight from our everyday lives.

Or so I think. Happy to be disproven!

[luhn]

~20% is residential—still significant. Plus ~30% transportation, which as we transition to EVs become more and more relevant to residential energy use.

But even commercial and industrial could be optimized in the same manner. I've been thinking: If electricity is much cheaper during certain periods, would factories be built to only run during those times?

https://www.eia.gov/energyexplained/use-of-energy/

[d4nt]

This is already a thing, but it‘s only done at “enterprise scale”. Meaning account managers meet with energy purchasers at large manufacturing plants to negotiate “interruptible supply” contracts. The notice periods, levels and tariffs are all negotiated individually. “Pricing managers” on both sides of the negotiation spend a long time modelling the deals in Excel. If algorithms could replace the pricing managers that would save both sides some time and money though, not to mention making it available to the residential and SME market.

[aembleton]

If you're in the UK, then Octopus Agile tariff gives you a variable price and an API with IFTTT integration so that you can switch devices on and off depending upon the current price: https://octopus.energy/agile/

[OJFord]

That's really cool, for all the spam/ads I have seen about Octopus I've never seen this before, and this is the first time I'm interested. (Ordinarily I'm only interested in price, viewing it as a straightforward commodity, and Octopus has never been appealing on that ground.)

[omniscient_oce]

This is already a thing in Australia

[bluntfang]

Just because something isn't "environmentally important" (whatever that means) doesn't mean you can't optimize it. We need to shift into the mentality of thinking about the environment. Don't slap the hand that's interested in making a difference.

[BurningFrog]

You can optimize small things, but it will only have a small effect.

Better than nothing, sure, but the danger is that you only deal with the small things because you're not even aware of the big ones.

[konschubert]

This will only work with fine-grained energy pricing (on the scale of minutes) and smart meters.

Does this exist anywhere in the world?

[kerridge0]

Octopus energy in the UK with the beta agile tariff is based on 30 minute pricing and prices have been so low at times such as yesterday that the price per unit has been negative, for example on Sunday and Monday I was paid 4.2 pence per unit to take electricity off the network.

[lovemenot]

Their web site advertises support for IFTTT. Has anyone here hacked on Octopus APIs? Looks very cool.

[dharma1]

Yeah I have a bit. I'm on their Agile energy with half hour pricing intervals (this is what the smart meter standards give).

It's really cool. Sometimes the price goes below zero - "plunge pricing" - if there is too much production and too little use. They give you the pricing info for today and tomorrow ahead of time, not sure how they predict future pricing - probably based on weather forecasts, since they only use solar and wind?

I have WiFi smart sockets on things like electric heaters to turn them on when electricity price is below my threshold level. It's a nice feeling being paid for using electricity. If you have an electric car you could also programmatically only charge it when electricity price is below a certain level. Octopus also have an EV leasing company, thinking of selling my current car and leasing one from them after covid19 is gone to a degree that I still need a car again.

Here are their dev docs:

https://developer.octopus.energy/docs/api/

They even have an open graphQL API and a storybook - how many utility companies you know who do this? Looks like Octopus hired the right people!

https://api.octopus.energy/v1/graphql/

https://octopus.energy/static/common/storybook/account-manag...

[kimburgess]

Providers are starting to pop up in Australia that support this, and people have been quick to start hacking: https://twitter.com/_______kim/status/1226606021558194176

[eximius]

Griddy in Texas is a wholesale energy provider for consumers that passes on the fees set by the Texas grid regulatory agency every 5 minutes.

[jdofaz]

I think Griddy is a cool idea but only if you have something to automatically cut your usage when the price spikes to $9 per kWh like it did last summer.

[eximius]

It spiked to the regulatory max of $5, which hit me while I was at work. I still saved money compared to most other energy plans in my area.

Though yes, it would have been better if I could have adjusted.

[johnb]

It does in Australia: https://www.amberelectric.com.au/ (disclaimer: I work there)

[gregoryl]

I can see you're hiring; I'm on the market, what's your thoughts about the workplace? Super interesting industry!

[mattygh]

Not true, it would work with hourly pricing. Still requires smart meters but those are something like 60-70% of homes in the US now. Even without real time or time of use based pricing, load shifting can still be valued and paid for as a service. Look up Demand Response: >$1Bn market in the US.

Edit: https://en.wikipedia.org/wiki/Demand_response

[WalterBright]

Since solar energy doesn't happen after sunset, the idea can still work even just assuming power is cheaper during daylight.

[folmar]

There are even open protocols used in the wild. SunnyHome has it working for example for using your local solar electricity.

[beckingz]

It works well if you can aggregate the distributed resources so they're large enough to bid at the wholesale level.

[mattygh]

The market is a little more dynamic than that, wholesale bidding into the ISOs is still the biggest option but many utilities run load shifting programs of various sizes as well.

Still, the conclusion is like you said. There's basically no real-world scenario where it makes sense for a residential customer to go it alone, because they can make at most a couple hundred bucks a year. So makes sense for their device companies or someone else to figure it out with utility and pay thousands of homeowners to agree to participate. Ohmconnect has a cool service in California.

[beckingz]

Demand response programs are great because of their scale and ability to provide incentives and command and control without directly interacting with the markets.

The real big thing is aggregating the aggregations. Distributed Energy Management Systems (DERMS) / Virtual Power Plant Management Systems are an active research topic.

[konschubert]

one could imagine a company that gives fridges out for FREE and sells the aggregated “balancing energy” to recoup the cost of the fridge.

[lovemenot]

I like the business model. But it'd surely be advertising at you too. The pressure for the owner to pick up those free dollars would be just too strong.

[jtr1]

[deleted]

[mattygh]

Sense is great, but way overkill for demand response. Also, measurement needs to be billing grade accuracy, and I don't think Sense is going for that

[harikb]

Fridge is typically placed inside a house, unless we are talking about some alternate kitchen style. If so, ambient temp inside an apartment/house that is already heated or cooled is somewhat constant I assume. If so, where is the savings?

Also freezing it more in day doesn’t allow me to freeze less at night. If I don’t open the door at all, then the insulation is already taking care of this. What am I missing?

[hansvm]

There are a few things going on here.

First we need to address the basic premise that could allow this to make sense at all in some house or environment -- that one can afford to freeze less during the day if they freeze it more at night (or vice versa).

For a fridge this is hard because you're usually targeting a narrow temperature band (don't want to accidentally freeze your veggies), but for a freezer it usually doesn't matter if you get it 10-20 degrees too hot or too cold as long as everything remains frozen. In that case, your losses (whether they're through the insulation or an open lid) will be higher with a colder freezer, so even if you could get your freezer down to e.g. -200 it might not be cost advantageous to do so, but colder temperatures definitely buy you some extra time. E.g. if normally your freezer is at -5 and you instead cool it down to -10, there will be a nonzero amount of time before it heats back up to -5 again (and the amount of time can be large if your freezer is well insulated and has a high thermal mass).

The "closed system" aspect of this is also interesting.

The cheap answer is that not all houses are heated or cooled (mine isn't), so you can sometimes ignore that part of the equation.

A better answer is that everything mostly works out the same even for closed systems. Suppose you have A/C that cools your home to a target temperature. When your freezer is running it moves heat into the living space, which then needs to be moved outside. As a system, you can pretend those two units are working together to move that same quantity of heat outside, and when the freezer is off you're just not operating that entire heat pumping system (assuming linear power demands and a host of other things to make the example tractable in a comment). While the freezer is off it will also assist in cooling the room down, further alleviating A/C power demands during peak hours (not alleviating them much, but helping nonetheless).

If you're instead heating the room to a target temperature, everything works a bit in reverse. The freezer alleviates heating costs while it's running and exacerbates them while it's off (and critically, it exacerbates them more than if you assumed a constant, low power draw because we're intentionally decreasing it's temperature below a typical freezer level and thus increasing the rate at which heat will enter it from the apartment by some small amount). Assuming you were trying to run the freezer during low cost hours, that effect might be large enough to offset any gains. I doubt it, but that's just a hunch, and I haven't run any hard numbers yet.

[labawi]

It might not be a good idea to temperature cycle your freezer contents, as it speeds up degradation.

[myself248]

Dang, I can't find it right now, but there's a service out there that pays you to reduce your consumption on demand. Use their app to link up with your smart appliances and stuff, and the rest does itself.

Basically they've plugged into the ISO as a "generation" resource, and when the price of power goes high enough, they say "okay we can produce that much power", and they have all their users reduce that much power, which has the same effect. They get paid for the power, and pass some of it along to their users.

[dx034]

The problem is that with modern fridges energy consumption is already low enough that steering that through smart meters probably isn't worth the investment. Large companies could use that, esp with electric heating. But in residential areas, I think energy efficiency can still yield greater results.

[ajuc]

There should just be a common protocol for all electical devices - heaters, washing machines, vacuum cleaners, computers, TVs, toasters - everything. Some devices might ignore it, but they should still have the data port and the microcontroller responding with "power regulation not supported". The state should regulate that like it regulates normal power sockets, it's a net benefit for everybody and the cost is minimal.

We can just add usb port to regular wall sockets and make a new power plug with that.

Of course the socket should be backward compatible, but any new devices would require the full plug and responding to the protocol.

Over 10 years we could have an effective grid-wide gigawatthour battery. And everybody would only pay for it like 5 USD every time they buy a new device :)

The cost of a cheap microcontroller, power regulator and an usb plug is like <5 USD. And the possibilities of energy savings are huge. There are also big usability improvements (want to have lights learning your habits and pretending you're home when you're on vacations - someone will make that product).

Want to make sure you switched off that iron when you went to a party? No problem - connect with a smarpthone and check (and switch it off if needed).

There could be several categories of devices with different priorities and default power settings that you could change if you want to:

- background, critical

- background, optional

- background, opportunistic

- interactive, critical

- interactive, optional

- interactive, dangerous if left alone

- bidirectional (like Tesla wall, or a car charger if you want to power your house from your car battery when there is a blackout)

And the house could detect if you're home, and disable the iron if you're not and throttle the freezer and all heaters to optimize the power usage.

Automated vacuum cleaners nad chargers could start by themselves when the energy is effectively free and stop for a moment when there's a shortage.

This will get especially important when electric cars are more common - you don't want everybody to start charging them when they get back home.

[4h53n]

I do agree with your overall suggestion, but it would be a mission impossible to change sockets. Indeed, technology for communication over power-lines are nothing new, and doesn't require a new socket/wiring: https://en.wikipedia.org/wiki/Power-line_communication

A grid supply status, could empower next gen energy saving home appliances. This could be implemented as simple as pricing, the ultimate incentive. Price would fluctuate on the wire, just like it does for energy market.

[ajuc]

> it would be a mission impossible to change sockets

Why? I lived through one such change in last 30 years (switching from 2-pole europlugs to CEE 7/7). They are backward-compatible, but so would be the usb+power plugs.

We also switched from 60 Hz 240V to 50Hz 230V some time in 00s (don't remember exacty, it was a non-event).

As for incentives new electronic devices should simply be reqired to have these plugs and microcontrollers, like now we require them to have fuses and certain wire gauge, etc.

Why depend on a hack when you can do it right?

[the8472]

Adding a data bus to all lines would be a much bigger deal than changing sockets for existing lines or running a slightly different voltage (often within tolerance of the power supplies anyway!) over the same wires.

And USB isn't meant to operate over those long distances. So you'd either need some active component in each socket or devise a new standard.

[ajuc]

It doesn't have to be usb, maybe ethernet would work? Or something new if needed.

Rewiring might be a problem (but it was the same with adding a ground wire).

If we have to we can do the data-over-power between the sockets, and use data lines from sockets to devices.

This would ensure devices don't have to adapt to that hack and eventually we'll have a clean solution.

[joeyo]

People are hacking together some interesting things in this space: https://fridge0.branchable.com

[maelito]

> A great deal How much in % ?