What can I do with extra electricity?

Question

I'm looking at solar power systems, with the intention of eventually not being connected to the electrical grid at all and only having intermittent internet access.In order to do that I need to over-provision my solar panels. Solar panels remain a lot cheaper than batteries, so for me at least it makes sense to get a lot of solar panels and only a few "hours" worth of batteries.Let's assume that some sunny days I have an extra KW of power generation for ~8 hours. On overcast days I probably don't have any extra power, unless I'm not at home and can shut everything down.What can I use the waste electricity for?

ldiracdelta · Accepted Answer

I'm in Washington state and I'm not sure what latitude you live at, but for my house, my low, without snow on the panels, is about 8 kWh for an overcast day in December or January and my high is 107 kWh for a day in the middle of summer. For me to average out my needs I need a dam... like on the Columbia. In WA state, you don't sell the power, your extra power is future credit to your power needs. I'm on a heat pump and my highest demand is in the winter where lows dip to 15F or 25F. For me to save up enough energy on my own land would require more of a pond pumping scheme and it would be a massive undertaking. On the order of being able to store huge portions of energy for a quarter to a third of the year to get through winter. FYI, my system is Goldilocks's just right. I pay about $25/ year for extra power once my credits run out at the end of winter.I've bought two different solar systems in two different states and the devil is in the details for your hypothetical situation. You need to understand average overcast days, ~90 percentile run of overcast days in your lowest intensity sun month, intensity of sun, angle of the sun, et c. Also, if you optimize for the worst days of the year, you could be reducing total energy output because your panels would be optimized for a lower sun angle.

sliken · Answer

To minimize battery needs, anything that requires power. Charging power tools, drying clothes, pumping water, washing clothes, cooking food, running the fridge, running the AC, vacuum etc.You can save a surprising amount of money by just running the most energy intensive appliances during peak solar.

iSoron · Answer

You can sell it to your local utility company. You will get paid for it, and another power plant somewhere (maybe a coal power plant) will need to produce 1 kW less power.

petermcneeley · Answer

I can highly recommend Gas diffusion. It consumes electricity like one might expect from a multistage refrigeration unit. The results will guarantee your permanent "off the grid" independence comparable to any other nation. https://en.m.wikipedia.org/wiki/Gaseous_diffusion

mkj · Answer

Grow some plants or algae faster by shining extra grow lights on them, in addition to sunlight?

mcint · Answer

Check out joeyh's stuff, https://joeyh.name/, esp https://joeyh.name/offgrid/
Energy storage, whether purchased batteries or built gravity storage is likely most useful.
Having consistent access to power through predictable reserves makes energy way more useful to you. You can do laundry at night, or run a heater, etc.
Storing energy allows you to adapt your power usage to your needs and preferences, instead of adapting your needs and preferences to power availability—which has daily and seasonal limitations.

fbhabbed · Answer

Distributed computing for citizen science. BOINC, for example

aaron695 · Answer

> What can I use the waste electricity for?
You can't. That's really the end of it.
Lots have tried and failed. You can pick a fun project that you might get some skills from but it's not really a real answer.
It won't beat batteries which you've already spec'd out.
Best you have is move chores when you have extra electricity. Washing, download torrents, watch TV, run the pool pump, heat water, dry food.

vijay_nair · Answer

I'd buy Tesla Powerwalls&sup1; and charge 'em up. One of them can store upto 13.5 kWh of energy and going by your comment below (190 kWh/30 days = 6.3 kWh/day, which seems in line with "I have an extra KW of power generation for ~8 hours" for peak days), it seems two of them costing $14k as per their calculator can handle 4 days worth of surplus.Not sure if the economics would work out in your favor&sup2; but I personally consider going off-the-grid worth the cost.&sup1;https://www.tesla.com/powerwall&sup2;subsidies: https://www.tesla.com/support/energy/powerwall/learn/incenti... (could potentially knock off 50% of the cost if you qualify)

shoo · Answer

https://en.wikipedia.org/wiki/Aluminium_smelting ?

knopkop_ · Answer

Mine some crypto

snarfy · Answer

Fill a small water tower

NoCanDo · Answer

Gravity batteries. Get a million gallon Tank on 10-20m stilts, pump water into it with ONLY waste electricity.Let water flow out of it and power a turbine during times where electricity is needed.

GoToRO · Answer

Wood pellets, irrigate, fill-up battery powered tools, turn on AC.

EADGBE · Answer

Solar powered server?https://solar.lowtechmagazine.com/about.html

programatico · Answer

energy efficient server:old link https://www.theregister.co.uk/2010/11/11/diy_zero_energy_hom...Make hydrogen (H2)with electrolysis. Need to found a good technology for that, and be careful hydrogen is very explosive.

JoeAltmaier · Answer

Distill hydrogen for your new hydrogen car

boring_twenties · Answer

Get a Ryzen CPU and mine Monero with it.

jtn_001 · Answer

Create electric car charging station

catwhatcat · Answer

Gravity batteries!

PaulHoule · Answer

Heat water?

Angostura · Answer

Get an electric car?

yourpalkeith · Answer

Please don&rsquo;t increase your energy consumption just because you are generating an excess. As a world, we need to lower our energy use (as I&rsquo;m sure you are well aware). I&rsquo;d urge you to consider those extra watts as a much needed contribution to the cause.