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Ask HN: What to do with excess off-grid solar electricity?
7 points by deviance 1901 days ago
I'd like to bring to attention the question asked here:

https://permies.com/t/85965/Economical-excess-grid-solar-electricity

""" William Bronson wrote: What can we make to sell from any excess electric? Compressed air? Nitrogen or oxygen extracted from.the air? Ice? Dry ice? Purified water? Milled lumber? Split firewood? Hydroponic weed? Hydroponic hops? Server space? ... """

I'm interested in ways of turning the excess electricity + extra work on my behalf + whatever needed equipment into something which is sell-able / profitable. The prices offered by the government for feeding in electricity into the grid are miserably low where I live.

Ideally, the proposed ideas should not be dangerous (e.g. "Compressed air") and not require a substantial initial investment and/or special licensing.

The idea of making ice (mentioned above) and selling it, seems actually pragmatic enough, but there is not much demand for it where I live.

6 comments

If you live in a cold climate turn it into heat and store it in a thermal battery. The engineer behind the ElectroDacus has an incredible open source resistive heating controller!

https://electrodacus.com/

Maybe a cheap "data center". You could run servers for local businesses that want to have a website but don't need high reliability. The equiptment doesn't have to be the highest end stuff either for local companies with static sites.

You could set up a car charging station. Maybe one of the existing companies would want to put one in if they know they can get energy from you at a discounted rate (like paying you the market generation rate but not having to pay a transmission fee).

Like a lot of things in life, this boils down to a political problem.

Change the laws in your area so the electrical utility/grid operator is required to buy it from you at prevailing rates.

This is the case in many (if not most) areas of the USA. Excess power simply feeds back in the electrical grid. The electrical meter works both ways so power feeding back into the grid runs your meter backwards. If this reduces your bill to less than zero, the utility will send you a check for the amount due.

Long term food preservation seems like a good bet. Freeze-drying, for example, will minimize both transportation and ongoing preservation costs .
Along these same lines, you could sell sterilized stuff, like mushroom substrate.
Overall the cheapest option is usually to curtail the excess production.

Energy storage costs money.

Useful industrial processes that need electricity cost money to set up. The lower the utilization factor the less the cost of electricity factors into the total cost.

That said, time shifting load is the way to go to consume excess energy.

Mine cryptocurrency is the obvious answer.
I initially considered this as well (still considering), but I am a bit reluctant - a decent mining rig can be quite expensive - and I keep hearing or stumbling myself upon both pros and cons.

Some of the cons: - Bitcoin mining is now feasible only? using ASIC miners. They cost a lost and I can't find a reliable source to buy them (i.e warranty for hardware breaking down, etc.). - Bitcoin prices are very volatile, so if they go down (even for a limited period - e.g. up to a few years) I would be stuck with (temporarily) unprofitable equipment. - Ethereum (for example) is minable using GPU-s (less risky investment from my point of view) but I hear in the near future it will transition to proof of stake and not be minable anymore (correct me if i'm wrong)

For more info you can check on whattomine.com to see if any alts may be profitable to mine with GPUs.