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Comment by bombcar | Hacker News Reader

> Tesla for home appliances: re-inventing home appliances (water heaters, induction stoves, clothes dryers, etc) to create better consumer experiences using specific advantages of electric technology.

I mean heat pump water heaters already exist [346] and they're reasonable in most everywhere (they put extra load on the furnace in cold climates in the winter but can still be a win overall). The main advance here might be more "smart integration" with the grid, but that is going to have to be a national level thing.

[346] https://www.energy.gov/energysaver/heat-pump-water-heaters

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>water heaters

Are we being serious? I have an electric water heater. I have an induction cooktop, which is electric by necessity. I have an electric clothes dryer. (Is there even a consumer-grade gas-fired clothes dryer on the market?) The consumer experience is fine. I turn on the hot water tap and hot water comes out. What am I missing?

The only thing I can think of is a water heater that knows when power is cheap and preheats water hotter than it needs to be so it's available when you need it without using power ... I guess?

This is becoming quite common in Finland (thanks to insanely high spot prices of electricity). Shelly is usually used to do the automation. Note that the water is not heated "hotter than necessary" but rather water is heated up to the max amount when the price is cheap.

Traditionally water heaters were only on at night.

Yeah the "max amount" can vary - I have mine set higher than "you should" to prevent Legionnaires' disease and then have a mixer that reduces the temperature back to safe for the house.

https://www.amazon.com/Cash-Acme-Thermostatic-Temperature-Ap...

That's a very low tech solution that could take some advantage, and thermal mass of water is pretty high, especially if the tank is well insulated.

This has started in California in the form of a utility pilot that controls heat pump electric water heaters. I know because I'm a participant in the pilot.

The opportunity to reduce carbon emissions is pretty massive when done at scale, because water heating accounts for 25% of home energy use in California.

In general, there is a big rush of companies, both startups and established, into the DER space right now, I suspect because of both the relatively low cost of entry and the high value of the grid services (frequency regulation, peak load avoidance) they are usually bidding on.

You mean you don't want to download an app to your phone that steals your data so you can....adjust the temperature setting of your hot water heater?

If you're heating hot water you already have a problem ;) (I know, I know).

One existing water heater innovation:

https://www.mixergy.co.uk/products/mixergy-tank/

Has both stupid innovation (Alexa integration) and sensible (working with the grid to balance demand, innovative design that saves energy and heats up faster when you need it quickly)

Efficiency by heat pump

You just need a spot market for electricity and then you can program the water heater to follow the spot price (or rather avoid heating when it's expensive).

This is available already in a few heat pump water heaters in Finland.

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