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defrost 2 days ago

The article is talking of the revival of [solar {...} thermal] storage precisely because solar panels are so cheap and heat pumps are reasonable.

The {...} is the counter intuitive step of solar -> electric -> heat storage for six months -> electricity for later.

The secret sauce is increased heat deltas, not just heating dirt directly using sunny daytime temperatures but really cranking up the heat of an underground mass to 500C + (IIRC - I skimmed the article some hours ago).

pfdietz a day ago | parent [-]

This idea has nothing to do with heat pumps.

defrost a day ago | parent [-]

Not the somewhat recently popular specific household commercial gadgets for cooling and heating a home, no.

Just thermodynamic pumping of heat, from the article:

  Electricity from the solar arrays flows to heating elements in the earthen mound, building up heat. The storage temperature is 600 °C or higher. The outer mass of the mound, plus a favorable volume-to-area ratio, insulates and minimizes heat loss. Pipes embedded in the mound carry fluid that delivers heat to users.
and at industrial scale, using bleeding edge HVAC technological advances, it's all about the creation, storage, and pumping of heat.
pfdietz a day ago | parent [-]

Resistive heating isn't pumping heat. It's turning zero entropy energy into heat. An ideal heat pump, on the other hand, creates no entropy.

defrost 21 hours ago | parent [-]

Operating a digger to move dirt isn't pumping heat either, if we're listing project components that aren't pumping heat.

I'm guessing you caught but ignored the part that is moving heat?

pfdietz 21 hours ago | parent [-]

One can move heat from one place to another by moving a fluid. This is not a heat pump, even if the fluid is pumped.

A heat pump is a specific kind of thermodynamic device that moves heat energy from lower to higher temperature.

The system that is described in the OP link does not use a heat pump. Electrical energy is used to make heat, but it does so with a resistive heater, not a heat pump.