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Comment by the_third_wave | Hacker News Reader

We have a dynamic (hourly rates) contract as well and well and we sometimes see negative electricity prices. This does not mean electricity ends up being free since there is also the transmission charge, energy tax, renewable energy surcharge and value added tax on all of these to pay. Do you actually get paid to use power, i.e. do you not have to pay any of the mentioned charges?

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If they do get 100% free, this continually reraises a question of mine: outside of crypto mining, is there anything a consumer can do to capture benefit from free electricity? Low efficiency synthesis of ethanol, hydrogen, carbon capture, desalination, precious mineral enrichment from seawater? With net metering rates tanking, I would love to see some way to productively capture spare juice. The duck curve is not going anywhere.

Easiest is probably using your house as a thermal battery and just temporarily dumping energy into cooling or heating down to a set temp and then when allowing your house to normalize when prices go up.

Alternatively, charge your own batteries and load balance. It's boring but effective.

You could have your computer queued to run high energy ops when free, queue training models, compiling, etc. Which would generate a lot of heat, thus cranking the AC.

I could see how this could easily 10x your power draw for a few thousand dollars and work in the background.

If in a cold climate, heat the earth under your house. Then, that earth slowly gives its heat back to you over the coming months (soil is quite a poor thermal conductor, so the heat hangs around underground for a really long time)

Obscenely powerful heaters are rather cheap. Assuming prices only go negative pretty rarely, you really want 100 kilowatts or more of heaters under your house to get as much free power as possible.

Residential power here for single family homes -- the type which could reasonably do what you suggest -- is almost always single phase 120/240V. As an upper bound, let's consider 400A service. (Most homes have services smaller than 400A, and even 400A service is typically delivered to a pair of smaller panels to keep conductor and busbar sizes manageable.) Such heaters would be considered continuous loads, reducing the 400A service to 320A of current. Resistive heaters are a linear load, so we can multiply 240V * 320A to get 76.8 kW at maximum.

Hitting 76 kW is wildly impractical. Exceeding 100 kW is nonsense.

Often the base price is negative but you still pay some for taxes etc. Yesterday, net price was also negative because the base price was so ridiculously low...

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