zlacker

The article omits some critical details:

It says this is both a "heat pump" and also "storage" AND says that it will run when electricity is cheap or plentiful. Thus:

1: Where does it pump the heat from? (Or is this not really a "heat pump" and instead is using resistive heating?)

2: How long does it store heat? Is this something that will store heat on a 24-48 hour basis, or will this store heat during the spring / fall when longer days mean extra power from residential solar, and then use the heat in the winter?

3: Is the unit itself "warm" when storing heat? Or is the heat stored in a purely chemical way and needs to run through a catalyst or similar to get it back?

4: Can this be scaled up for general domestic heating?

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Just an FYI: There are plenty of schemes with resistive electric water tanks to store heat when power is cheap.

>>gwbas1+(OP)
I would guess that is intended for a daily cycle, perhaps using air source heat pumps at times of day when the air temperatures are higher and electricity prices are lower, then using it as required.

As it works on phase change (e.g. think of melting ice) heat is added (or removed) without changing the temperature of the store (which, I guess, might be hotter or colder than where the heat is extracted or used).

>>gwbas1+(OP)
1. The device is just storage. It would be paired with an air or ground source heat pump.

2. With good insulation you can easily store heat for a day which is all you need. You're never going to get close to storing summer heat for the winter. That's not impossible but not feasible for something this scale (and not cost effective at any scale).

3. You just heat it up and cool it down. There are no fancy chemical processes happening other than the phase change. It's exactly like a phase change hot/cold pack you can buy on Amazon.

4. I'm pretty sure this is designed for domestic heating...

It's kind of an obvious idea tbh. I don't think they've done anything super innovative... They made an aluminium heat sink..

>>IshKeb+e5
the only new thing- no matter how they do it- is putting it on residential instead of commercial or industrial installs.

my childhood public school took us to some big commercial building- I think it was Sears' HQ- and they proudly showed us the huge blocks of ice providing chill during the day.

>>gwbas1+(OP)
Presumably it's air source and if it's indoors it will just be the air in whatever room it's in. That's how my ventless dryer works. I'm not sure what the implications are for taking heat from air that may have been heated by another heat pump are for efficiency. But also if it's summertime, they may be relieving load from your air conditioner.

>>mike-t+95
But how hot does the heat source have to be?

Depending on the needs, resistive heating can get hundreds of degrees hot, but the best heat pumps that I know of can only raise the temperature about 60 or 70° f.

>>IshKeb+e5
> With good insulation you can easily store heat for a day which is all you need. You're never going to get close to storing summer heat for the winter. That's not impossible but not feasible for something this scale (and not cost effective at any scale).

This is ground basically. How deep varies but few meters underground you basically have average yearly temperature. You could pump heat from house to the ground to take it out from the ground during winter.

>>gwbas1+9S
That's the whole point of this, no? Heat pumps can't heat up a large amount of water quickly (like resistive heating can). So if you have a solar peak at noon, where either yourself are producing cheap solar, or there's cheap solar on the grid in general, then you want to use that cheap energy to store heat for later use (like showers in the evening/morning).

So the way I see it, is that this material should be able to quickly store heat with the using the low temperatures that heat pumps provide, and be able to store it with minimal losses until it is needed.

>>jcattl+gw1
> Heat pumps can't heat up a large amount of water quickly

No, it's about temperature difference. My heat pump water tank heats about as quickly as resistive water tanks; but it could never heat to hundreds of degrees.

>>tootie+kO
> That's how my ventless dryer works.

Do you mean a heat pump dryer? Those aren't taking heat from the room; they work by sending the air inside the unit through a powerful dehumidifier. (I have one, it's very nice.)

>>gwbas1+2I1
A dehumidifier is the same thing as an air conditioner. The coolant coils are still just exposed to the ambient air in the room. The same way a window air conditioner drips moisture, the dryer is like a backwards air conditioner that blows cold air into the room and hot air into the drum and condensed water drips down the drain. I suppose it ultimately doesn't matter once you open the dryer door and everything mixes together.

>>tootie+Go4
My heat pump dryer does not blow cold air into the room. (My heat pump water heater does.)

The air inside the dryer is cycled through a dehumidifier and then the water is pumped out into a drain. This is in contrast to a typical US dryer that just blows hot air into the drum and then out a tube outside. Apparently most of the world doesn't do it like we do.