Surplus electricity

hot water?

Not a large enough scale -- I'd thought of heating a pool, spa, etc. Though if neither of those gets *used* while the water is hot, the energy is effectively wasted.

Bitcoin mining.

Isn’t cryptocurrency mining the go to now?

To be practical, that requires specialty hardware that has little value for anything OTHER than mining bitcoin.

I currently leverage "periods of surplus power" to retrain models, transcode video, run extensive diagnostics, etc.

But, there is a limit to how much power those actions can consume (because they were designed to be efficient).

"Making ice" is likely a practical use. But, it, too, requires special hardware that can only be used for that purpose.

A crypto-miner in baseboard heater form factor! Multipurpose appliance for colder climates. Deduct your profits directly from your monthly utility/heating bill.

The most common one is turning it into bulk hot water that you can easily store in a super insulated tank. Or charge an electric vehicle.

The other possibly better option is to add some more batteries!

Typically its heat, hot air or water. I guess with a peltier device you can cool too, at a efficiency loss.

Cheers

Is it solar?

It's funny that in this greenie world, electricity sometimes has a negative value. You have to pay people to take it, or to not produce it.

Get someone to pay you for not making those KWHs.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Clean water stores much better than heated water or frozen water. I'd suggest that water purification (ideally of wastewater, which is much easier than seawater) would be a good peak-only use.

Not worth doing everywhere, but certainly in some places. Reverse osmosis can have a short duty cycle, at least shorter than distillation schemes.

bob prohaska

I think RO produces lots of "waste" water (?). We don't have easy access to "salt water".

Could you use it to do something that would otherwise be a net negative, like removing CO2 from the air and turning it into oxygen and diamonds? Or methane?

Rainwater is usable with only pumping and maybe sterilization input. That takes very little energy. Desalination costs about 1kWh/cubic meter for seawater at the theoretical minimum. Realistic costs are 2-3x higher.

Thus my suggestion to reclaim wastewater, which everybody has 8-)

The amount of wastewater is roughly proportional to input salinity over energy budget. If the input is cleaner, in the sense of TDS, the waste amount goes down.

All for a given energy budget and pretreatment cost.

bob prohaska

At the very least, it has to be heavily filtered (we have a lot of crap in the air -- PARKED cars end up *dirty* after a rainfall). Each year, I inspect/clean the roof. A powerwasher dislodges "black crud" that is likely automobile emissions that have settled on the roof.

And, we only get rain in two short periods each year. So, any collected rainwater has to be stored for months at a time.

Rainwater harvesting isn't practical for irrigation (at least not for water intensive plantings) as there is so little collected (relatively) and such a big need.

E.g., with ~11 inches of precip annually, we'd be able to collect (using rooftop, only), about 20,000 gallons in a year. Domestic water use is about 70-80 G/day/person so that leaves you with ~9 months for a single occupant.

We don't have access to salt/sea water so the larger problem is hte water supply, not processing.

Wastewater is hard to reclaim, here, as they build on slabs. You'd have to plumb from *each* drain instead of trying to capture that water at one point where it moves to the sanitary sewer.

I don't know how our rainwater would compare with municipal water supply (which is very "hard" water). As I said, we tend to have lots of crap in the air (think: haboob). OTOH, our municipal water is ground sourced so it picks up crap there.

Ideally, you want to do something that adds *perceivable* value to the owner/operator.

E.g., I presently do "work" that would otherwise be delayed/deferred when power is plentiful. Or, add "optional" tasks that might not be done, otherwise.

This manifests as a bit of a convenience but not a necessity in the user's eyes (he was expecting it to be done at a later time so may or may not benefit from it being "done" earlier).

Heating pool water can have a contrary effect -- if the user starts EXPECTING the water to be heated and effectively increases his "nominal load" to make that a reality (because he went swimming one day and the water was NOT heated!)

Thus, you have two issues to address: a "load" that can soak up a fair bit of "power" and a load that remains optional (or deferable).

once you've satisfied all the things you would otherwise use fuel for I can't think of anything.

But you do have water, or you wouldn't be living where you are. Your source of water is therefore your own discard stream. Cleaning that up and reusing it to the extent that's economical makes sense if the electricity required would otherwise be unused and you need the water..

That's a matter of money and planning, not technology. You might find it cheaper to replumb, maybe not. Combined grey and black water isn't impossible, though probably not practical on a home scale.. Composting toilets are one solution, but they have their own issues.

In terms of TDS (so, osmotic pressure) it's almost certainly far better. Unless the rainwater is collected on a soluble surface (limestone gravel roof, for example). That would saturate the water with calcium bicarbonate, and make the collected water hard.

Water scarcity first takes the form of water quality problems. That's where upcycling using surplus electricity might make sense. But the situation has to be dire, as on Mediterranean islands. And, soon, in the American Southwest.

bob prohaska

Brewing beer!

Plus you'll probably see a major algae bloom soon.

A guy in Texas had some sort of rate plan where the electricity charge on Sunday was zero. He dug a massive hole, lined it, filled it with water and froze that water, then used it to cool down his house on Monday. There was a bit of waste because the hole wasn't insulated.