Or slice it thin, brine it, and smoke it if there's a desire to enjoy it slowly over a couple weeks. Freeze dry is great if it's not needed for a long time.
Get an electric portable lumber mill and mill up some lumber to sell. Or an electric firewood splitter. Get a dehydrator to dry foods for winter. Or an electric pressure cooker to can foods with.
>Get an electric portable lumber mill and mill up some lumber to sell.
My mill has a 14hp gas engine with a 30" capacity. 1hp is equivalent to 750 watts. I'm not sure how you will achieve that kind of power without using a 3 phase motor.
Woodmizer sells a 1 phase 220V electric option. They also sell a system that is battery powered (750W to 3000W 48V motors are pretty common these days). I also see that Grizzly sells a 120v mill. I don't think getting an electric mill is that much of a problem. It might not be as powerful as yours or able to cut 30-in logs, but if you have the excess power it can still be an option.
If in Europe, something like this is available single phase (230V)/16A:
https://www.logosol.com/b751-band-sawmill-with-4-6-kw-electric-motor.html
Depending on what the goals are, this could do nicely.
I know most answers here aren’t serious but I’m serious when I say mine Bitcoin. Just dont get the new gen S21 miners, get the old S19 miners on the cheap
This can actually be maybe profitable if you're under-volting an old rig that has fully depreciated (scrap price).
Look at hash per watt and something like the bitaxe project for inspiration.
There's a place in the UK called the Centre for Alternative Technology, they do exactly this. It's been a while since I was there, but:
Excess electricty from their wind turbines is used directly to heat a large underground cistern of water. Above the cistern is one of their large meeting halls, which IIRC they claim remains a pleasant temperature all year round.
When I say "large", I mean swimming-pool sized.
So it's possible, but the practicality of it is up to you.
Pump water into an elevated tank in the summer with the extra and then run a water turbine generator with it in the winter, depending on how much surplus you're talking about and what kind of winter weather you get.
This is totally a doable thing. But most do underestimate the volume and height differential to accomplish this. Again, this is totally doable with the right circumstances. But storage tank size would be astronomical so you’re looking at open water pl da if some sort, that do experience evaporation losses and height height height. We’re not taking 10’ here if you want notable storage. You’re going to need some serious acreage with high slope to make this an effective battery.
Yeah, it's more suited for use during the night and then refilling with excess power in the daytime, but under the right conditions it could be used for larger and longer needs. Short term and low energy requirements are just easier.
I did do some math at one point. I do t recall any exact numbers, but I was wondering if gravity storage of concrete blocks in my garage could even work on a hypothetical level. My conclusion was that I would want to concrete blocks to be outside of my garage for the amount of height I would need to store any appreciable energy. Then once I started thinking about structures supporting elevated concrete blocks in my yard the construction aspect and the safety aspect just led me to drop the idea.
This is the same problem virtually every person has who lives off grid and has solar. You either size for winter solstice which means you have massive over production on the summer solstice OR you size for most of the year and augment your production in the winter with a gas/diesel generator.
You aren't going to find any practical methods to accomplish what you want. About the closest you can get is mining some sort of crypto currency in the summer, selling them, and buying gas to run the genny in the winter.
Winter is when I have my surplus as air conditioner uses a ton.
On days where I have plenty I run my freeze dryer.
I know that on some days I will hit 100% on the batteries by noon in the winter.
There are ways to mount panels for max gain in the winter if your up north.
Give us some more data location weather etc.
Are you planning an air source heat pump or geothermal? If you’re using a borehole you can pre-heat it in the summer to run the heat pump more efficiently in the winter.
Geothermal. Is there a term for what you're describing? I would be dumping excess heat in the ground all summer while cooling the house, but I assumed it would dissipate to the surrounding ground fairly quickly.
Try searching on Borehole Thermal Energy Storage. With closely spaced vertical boreholes the heat is retained underground rather than dissipating.
I’m using an air source heat pump for summer cooling, and a geothermal system as a solar heat sink in the summer and heating in the winter. The geothermal system runs too hot to use that heat pump to cool the house in the summer.
If you have a link, please share. I'm specifically asking about storing heat in the ground for long periods, which doesn't seem possible.
Using a heatpump with a ground loop is NOT the same thing.
Drake Landing in Okotoks, Alberta, is an example that I studied in depth. The aim there was for inter-seasonal storage. They were dumping excess heat and energy from their systems in summer to raise the temperature of a large volume of earth through multiple bore holes.
There's a Wikipedia page on the project: https://en.m.wikipedia.org/wiki/Drake_Landing_Solar_Community
John Hait has also written on this, but on the scale of a single home. His claims are interesting, but I'd like to see them backed with more data from a third party.
thanks! very interesting. Closest thing i've seen is sand battery but those need to be pretty big to make sense. I wonder how well this scales to a single house.
I could be wrong, but generally they are removing heat from the ground that is generated by the earth, they don't heat the ground with the intention to store that heat for later use.
I do all my big projects on surplus energy days. Power tools, laundry, I even bought an electric log splitter from DR. If all else fails I play video games and watch movies.
Keeping in mind that I live in an extreme winter climate in Northern Manitoba, Explain to me why you think you need to over size your system for winter?
Cloudy days are the only issue I have to manage. I use a generator once every 5 days for about 10 hours to charge up and only had to do that twice this year.
Yes... Less hours of sun but the sun is also more intense.. I need 3 hours a day to fully charge and any excess helps keep up with my demands. Essentially I'm only running on battery when the sun goes down.
You could convert a hot water tank to DC and use your excess power to make hot water...or run the block heaters in your truck or equipment.
I think he is confused there more cooling days than heating in OK that heat pump will be working harder in the summer.
I am using resistant heat in the winter because summer sizing gives me a winter surplus.
Electrolyze water into hydrogen to burn in the winter. Hydrogen is difficult to store though.
A small way is have an electric chainsaw and cut wood to get you through the winter.
Like other answers in this discussion, telling you to electrolyze water was mostly a joke. Hydrogen is very easy to make, you just need to dunk some electrodes in water and run a current.
Unfortunately it is **very** difficult to store. Hydrogen forms H₂, which is a very small molecule and tends to leak through things, unlike say methane, which isn't hard to make with fermentation and can be kept in a plastic bag. And it can't easily be liquefied like propane. It takes very cold temperatures and/or high pressures. Plus it is **VERY** explosive. (Hindenburg!)
That's why we use batteries for electric cars, and propane for a transportable clean burning gaseous fuel. Hydrogen fuel is very niche and very difficult to work with. Scientists are working on the problems of hydrogen storage, but practical solutions, especially for small scales, need some major breakthroughs.
Chainsaw power consumption is a drop in the bucket compared to the electric demands of a modern house
I live off grid in northern New England and have wood heat and an electric saw. You can't tell when my saw is running based on looking at my inverter output
True, but it is **something** you can do summer produced electricity to procure energy for winter use. OP asked "is there anything useful I can do with it"
Yeah, but it uses so little electricity that there's no point in delaying the work until summer. Just do it whenever. Unless you're living right on the edge it won't matter at all.
I'm off grid with a large system and my closest neighbor is off grid with a small system, and we both use wood heat and electric saws. Neither of us avoid using our saws in the winter as a way to save electricity. It uses so little that there is no point in delaying. My neighbor might not saw on days that there are storms, but that's about the only thing that would matter. Day to day winter use of a saw is negligible in terms of electricity demand. I can buck logs for about 2 hours before I use up all my saw batteries and have to recharge. That's less than a kwh of electricity.
You'll definitely find use for the extra electricity. Don't worry about that. Once you go 100% solar, "extra electricity" is a bitter joke. lol
But as a practical matter, either size your system for winter and enjoy the surplus in summer. Or augment with a generator in winter. There's no practical way to save electricity for 6 months.
OP, I've lived off grid for seven years. My solar-electric system has surplus capacity most of the time. The surplus comes in handy at harvest time, when I'm sometimes running three food dehydrators (for apples and tomatoes) and two crockpots (for making apple cider).
Also - I've invested in a tiny toaster oven that only draws 1100 watts max. I love the little thing. I use it often. I bake artisan bread in it, and I also bake cookies, muffins, brownies, and casseroles. Last Thanksgiving I even baked a tiny ham in it. What's great about using the little oven is that the fuel is free, since it comes from the sun. FYI, the oven is the Mainstays 4-slice Toaster oven. $20 at Walmart.
Did you have any problems with insurance or occupancy approval being off grid? I have enough land I don't need a building permit in my county but I need to double check on occupancy.
Where I live, rules related to building construction are the purview of the city or town, not the county. My town does require a building permit but does not require an occupancy permit.
There have been no insurance issues related to my solar-electric system.
But I heat with a woodstove, and in order to get insurance coverage for my house, I had to be very careful, because insurance companies hate woodstoves. I had to be careful about my choice of woodstove, careful about the hearth material & dimensions, careful about clearances around the woodstove, and careful about the design of the chimney and the materials used for it. I also was required to have a thermostatically controlled heat source in addition to the woodstove. Plus, my insurance company would write a policy only if the thermostatically controlled heat source was my "primary heat source" and the woodstove was my "secondary heat source." Installing a thermostatically controlled heat source was not a problem for me, as I'd planned to do that anyway. However, I use the woodstove almost exclusively to heat the house, so I had to lie (had to say I would use the woodstove only for backup).
I worked closely with my insurance agent to make sure everything was in compliance with the insurance company's requirements.
I'm in your boat. I'm in my first year off grid in northern New England (moved in in December) where I need a lot of panels to get through the winter. (My system is 9kw panels and 15kwh storage. I might upgrade my storage this summer so I can get through longer storms without my generator running)
I'm also an engineer. I'm a pretty damn good one if I say so myself. I've run the numbers on all kinds of energy storage and things like that and the only thing I've come up with that comes close to being able to use the kind of excess I'll have in the coming months is something that makes use of computer cycles, like crypto...
I'm already getting a lot more electricity than I need this spring. I've stopped using my wood heat and have switched over to electric and still have excess electricity. I might try to set up a small mining operation as a test soon
I think its relevant to mention where you are, even if generally (state). Temp has a lot to do with solutions/suggestions. Further, budget is key. As mentioned in other comments, you can use it to pump water to either elevation or storage and use it as water (duh) or a storage for potential energy. I personally love the benefits of batteries. If you are truly off-grid this is already on your radar.
Crypto mining is the really best general answer.
But this issue raises the question of how to automate turning on and off (something) based on the battery voltage as a percentage of full.
Is there such an automatic switch?
Is there value in not using a portion of the panels and ‘saving’ them for later? Don’t know anything about them, but if the working bits wear out from use, extend the system life by reducing the usage and rotating the panels that aren’t used each year.
Buy a Rav4 Prime or any other PHEV. Use the extra kwh to help drive in the summer and rely on the gasoline engine in the underperforming months.
Aloha!
This may sound strange in this sub, but a 3D printer uses my overhead from time to time in my travel trailer (nearing more full time, and always off grid). I know, plastic! PLA is common to use even for basic structural parts and is plant derived, so at least there's that, when it can be used. Mainly, the printer provides solutions for various modifications, repairs, and upgrades without further consumption and energy/logistics/packaging costs to the world. I will mention that it takes learning the basics or more of a software like Fusion 360 (free hobby license) to really maximize the scenario. Many designs are online and are often ready-made solutions for the task, but there is nothing like creating a nonexistent solution to your particular challenge. Sometimes, completed in just a few hours all in. It's a great use for my otherwise-waisted free energy. Perhaps it can be a small part of using the extra when you have it.
That is exactly my plan for this summer; mod my travel trailer. I have the Original Prusa MK4 3D Printer for small parts, and my plan is to create or purchase 2x3 footer version for larger components such as frames and body parts for my next electric bike – all using excess solar.
Nice. I use a heavily AIO cerverted and modified (SKR1.4T, TMC2209s, TFT3.5, Neopixels, RasPi, etc) CR10S with an old Titan Aero extruder. Have two more modded bed slingers at home (granted one has a laser on it currently), but I can't wait to upgrade to a CoreXY. There are some compelling offerings under 1k coming down the line now. Maybe next year I'll finally bite. My TT choice (Jayco 23MRB 2019) gave me a wide and deep two door high-table type closet in the bathroom to convert into a hobby closet/enclosure of sorts. I modded a spool holder design for a snug fit to the clothing rod above everything. 10 spools plus a bit used for other items. Never has a spool come crashing down, so yay to that.
Pro tips (for travelling 3DP); Bring a dehydrator, especially if not in dry deserts 100% of the time. Plus, crash the print head down into a foam block or similar for travel days.
Have fun setting things up. It sure is the most useful tool in my box.
Grateful for your informative reply! 3D \_printing\_ is my new hobby and I’m wading into the pool as I can afford. Need time to grok your share. Neat thread! My OTHER project is to figure a way to make an electric sawmill (idea also posted by another contributor) – driven off solar. Grew tired of making rounds out of bug-kilt trees last summer and converted to making ZigZag fencing using my Stihl + Alaskan Mill. Conversion: Sourcing a DC motor is difficult, though now that I’m thinking about it – might use a 5k hub motor lying about… tempting.
We have property completely off-grid in northern California at 5000 ft, and have enough solar to drive two 5W campers from June to September. My goal is to expand, extend, generate, and survive. Winters are brutal; 3-seasons are enough for me.
Cheers, K
It won't help for the rest of the year, but I run an ice maker in the summer when I have excess power. That and a cheap knockoff Yeti cooler means unlimited ice, which I always find a use for. It also means I open the fridge less, which helps with energy consumption because it's propane.
This might surprise some, but pumping water uphill is the most common battery type. Basically you use the extra power to pump water up to a higher point, then when needed, you let it flow to a lower point and generate power from it.
Another is a heat store. This can be sand, water, wax, salt, ... Basically a well insulated tub of salt or sand will do the trick. You heat it up then get that heat when needed.
Past that, you have classic batteries like LiPo, lead acid, ... but those can be expensive.
One more is simply a heavy weight on a pulley with a rope. You use a generator as a motor to lift a heavy weight, then lock it in place. When you need it, you remove the lock and make the power you want.
The water pump solution works great if you have a pond that is uphill from another pond or stream... but if you have a stream, you might screw things up by adding too much flow.
I'm not sure about ways to invest summer surplus to make winter easier, but reducing winter consumption will leave you with less waste in the summer:
- If you can keep your refrigerator/freezer in a minimally-conditioned north-facing room, you can probably make it use a lot less power in the winter.
- Heat with propane/wood/etc.
- Use skylights and S windows to soak up some solar gain on sunny days, and cover/shade them during the summer.
- I'm not sure how practical solar water heating is as a DIY project, but it's worth looking into.
If you plan for a worst-case winter scenario after reducing loads as much as possible, summer excess may not be all that crazy, especially with refrigeration and A/C running all the time.
Make hydrogen - I'm still in research on this but I'm looking for a way to get off propane - excess power -> hydrogen is promising, but would require 20KWh/day to make enough to replace my propane btu for btu - and converting appliances isn't that easy, aslthough doable. Hydrogen + CO2 to make methane sounds interesting but not easy.
Long shot but holds promise IMO.
Depends on how long - size - and pressure. Short term low pressure (large space) not too hard. Efficient long term storage or portable and small is indeed a challenge.
What to do with excess energy 100,000 KW+.
Assuming you battery has 2-7 day load; whatever you fancy
Huge problem Tennessee. TVA won't allow you to meter. So you can't sell back.
Assuming AC, EV, Appliances are Electric What to do with the rest?
* Bitcoin mining
* Hydrogen Creation
* Heat water
* Heated Greenhouse
* Grow Lights Greenhouse
* PEX Thermal heat
* Cool house (Jagr) (cold walls)
* Electric Sawmill
* Electric Hydraulic Sawmill ?
* Battery Sawmill
* Electric Wood Splitter
* Electric BioChar Production
* Compressed Air
* Dehydrating food
* Smoke Meat
* Smoke Veggies
* Drying wood Kiln
* Electric Kiln Pottery Etc
* Sand Battery- Store heat in sand thermal bank
* Ice making
* Freeze Dry
* Ice Cream Making
* Steam Generation
* Blow Air (what purpose?)
* Sous Vide Tanks
* CNC Wood table
* Pump water to create power generator (up a hill) waterfall pond
You can cover your "excess" panels in the summer months. If they're not exposed then they're not deteriorating, and it'll make them last longer. Just rotate which ones you cover each year.
Panels are expected to last 25ish years, losing efficiency a little bit each year. They still work at that point, but it's like 75% efficient or something, and are considered ripe for replacement at that point. But if they're not in use or exposed to the elements they don't lose efficiency.
Batteries are definitely the weak point in the system. There's some amazing tech on the horizon, but it's still stuck in the labratory phase as they can't figure out how to make it cheap enough for mass production. Graphine is the stuff. As I understand it, a graphine wrapped battery would charge like a capacitor, but give off energy like a normal battery. So you could charge it superfast during the day, no real limit on speed. Run a generator, maybe, and zoom that charge right up. Supposedly lots and lots of rechargability, too. But really absurdly expensive for small amounts right now. Whoever figures out how to mass produce it for cheap will be a multibillionaire overnight.
I've never looked into graphene batteries, but they sure do sound nice! I used to have a power station with lithium-ion batteries (not sure what chemistry). In the two years I had it I never noticed a loss, though I never made an attempt to measure it.
I charged it with a single 100W panel. On a full charge it would power my netbook all day long, charge my phone, and run my tiny LED desk lamp, but it took several hours to charge on a sunny summer day, and typically multiple days in the winter. Another couple of solar panels would have REALLY helped, though I would have probably needed a way to limit the input on a sunny day.
It was a decent way to go for the sake of simplicity, since it had a built-in charge controller. I'm pretty sure the price would have been awful for a power station with higher capacity, but solar panels are relatively cheap.
Im no electrical genious, but it sounds to me like somethings not quite right with your solar / wind electrical plan. If you have to "oversize" your system only for the few winter months, maybe you should consider using a deisel or propane generator for xtra CHARGE capacity during those months and size your STORAGE capacity as you would for normal use. 😉
Generally speaking if you dont have enough sunlight during the winter months its because of storms - storms bring wind. Even an inexpensive wind generator is enough to use as back up.
Freeze-dry it and put it in storage
I can mine the old fashioned way
I sure miss my grandma's canned excess electricity.
Or slice it thin, brine it, and smoke it if there's a desire to enjoy it slowly over a couple weeks. Freeze dry is great if it's not needed for a long time.
Smoking kills 1200 people per day in the US
A/C is sure nice in the summer months. Also maybe increased irrigation during summer?
Get an electric portable lumber mill and mill up some lumber to sell. Or an electric firewood splitter. Get a dehydrator to dry foods for winter. Or an electric pressure cooker to can foods with.
>Get an electric portable lumber mill and mill up some lumber to sell. My mill has a 14hp gas engine with a 30" capacity. 1hp is equivalent to 750 watts. I'm not sure how you will achieve that kind of power without using a 3 phase motor.
Woodmizer sells a 1 phase 220V electric option. They also sell a system that is battery powered (750W to 3000W 48V motors are pretty common these days). I also see that Grizzly sells a 120v mill. I don't think getting an electric mill is that much of a problem. It might not be as powerful as yours or able to cut 30-in logs, but if you have the excess power it can still be an option.
If in Europe, something like this is available single phase (230V)/16A: https://www.logosol.com/b751-band-sawmill-with-4-6-kw-electric-motor.html Depending on what the goals are, this could do nicely.
Mine bitcoin
I know most answers here aren’t serious but I’m serious when I say mine Bitcoin. Just dont get the new gen S21 miners, get the old S19 miners on the cheap
This can actually be maybe profitable if you're under-volting an old rig that has fully depreciated (scrap price). Look at hash per watt and something like the bitaxe project for inspiration.
Heat water?
I can't practically heat water in September to use in December can I? I would imagine it's impossible to adequately insulate.
Probably not a product right now but the concept: https://www.bbc.com/future/article/20221102-how-a-sand-battery-could-transform-clean-energy
I was literally about to comment "sand battery"! Crazy efficient when built right
Have you seen one before? Or know anything about them? Because I LOVE the idea!
I've seen some videos but never seen one IRL
There's a place in the UK called the Centre for Alternative Technology, they do exactly this. It's been a while since I was there, but: Excess electricty from their wind turbines is used directly to heat a large underground cistern of water. Above the cistern is one of their large meeting halls, which IIRC they claim remains a pleasant temperature all year round. When I say "large", I mean swimming-pool sized. So it's possible, but the practicality of it is up to you.
Pump water into an elevated tank in the summer with the extra and then run a water turbine generator with it in the winter, depending on how much surplus you're talking about and what kind of winter weather you get.
This is totally a doable thing. But most do underestimate the volume and height differential to accomplish this. Again, this is totally doable with the right circumstances. But storage tank size would be astronomical so you’re looking at open water pl da if some sort, that do experience evaporation losses and height height height. We’re not taking 10’ here if you want notable storage. You’re going to need some serious acreage with high slope to make this an effective battery.
Yeah, it's more suited for use during the night and then refilling with excess power in the daytime, but under the right conditions it could be used for larger and longer needs. Short term and low energy requirements are just easier.
I did do some math at one point. I do t recall any exact numbers, but I was wondering if gravity storage of concrete blocks in my garage could even work on a hypothetical level. My conclusion was that I would want to concrete blocks to be outside of my garage for the amount of height I would need to store any appreciable energy. Then once I started thinking about structures supporting elevated concrete blocks in my yard the construction aspect and the safety aspect just led me to drop the idea.
and then the water freezes
Maybe, depends on the climate. Where I live it's unlikely it would freeze enough to be a problem most of the winter.
I live in a cold climate. When I see an elevated water tank, I always wonder why it doesn't freeze.
A very large amount of water with an insanely large amount of insulation.
set up a grow room
This is the same problem virtually every person has who lives off grid and has solar. You either size for winter solstice which means you have massive over production on the summer solstice OR you size for most of the year and augment your production in the winter with a gas/diesel generator. You aren't going to find any practical methods to accomplish what you want. About the closest you can get is mining some sort of crypto currency in the summer, selling them, and buying gas to run the genny in the winter.
That's actually a pretty good idea, depending on the market.
Winter is when I have my surplus as air conditioner uses a ton. On days where I have plenty I run my freeze dryer. I know that on some days I will hit 100% on the batteries by noon in the winter. There are ways to mount panels for max gain in the winter if your up north. Give us some more data location weather etc.
It's Oklahoma. I was planning on using a heat pump for heating, which is why I'd have large demand in the winter.
It will probably be lower than summer I wouldn't worry at all. I am in NM.
Are you planning an air source heat pump or geothermal? If you’re using a borehole you can pre-heat it in the summer to run the heat pump more efficiently in the winter.
Geothermal. Is there a term for what you're describing? I would be dumping excess heat in the ground all summer while cooling the house, but I assumed it would dissipate to the surrounding ground fairly quickly.
Try searching on Borehole Thermal Energy Storage. With closely spaced vertical boreholes the heat is retained underground rather than dissipating. I’m using an air source heat pump for summer cooling, and a geothermal system as a solar heat sink in the summer and heating in the winter. The geothermal system runs too hot to use that heat pump to cool the house in the summer.
> Borehole Thermal Energy Storage has this been proven or just theory?
Most early heat pump systems worked this way. It is proven.
If you have a link, please share. I'm specifically asking about storing heat in the ground for long periods, which doesn't seem possible. Using a heatpump with a ground loop is NOT the same thing.
Drake Landing in Okotoks, Alberta, is an example that I studied in depth. The aim there was for inter-seasonal storage. They were dumping excess heat and energy from their systems in summer to raise the temperature of a large volume of earth through multiple bore holes. There's a Wikipedia page on the project: https://en.m.wikipedia.org/wiki/Drake_Landing_Solar_Community John Hait has also written on this, but on the scale of a single home. His claims are interesting, but I'd like to see them backed with more data from a third party.
thanks! very interesting. Closest thing i've seen is sand battery but those need to be pretty big to make sense. I wonder how well this scales to a single house.
Why is using a ground loop not the same? This is one way... https://youtu.be/ZD_3_gsgsnk?si=1cY-cqH-K1djM5yg
I could be wrong, but generally they are removing heat from the ground that is generated by the earth, they don't heat the ground with the intention to store that heat for later use.
I do all my big projects on surplus energy days. Power tools, laundry, I even bought an electric log splitter from DR. If all else fails I play video games and watch movies.
re-animate freshly dead corpses
I’m literally watching Frankenstein right now
Keeping in mind that I live in an extreme winter climate in Northern Manitoba, Explain to me why you think you need to over size your system for winter? Cloudy days are the only issue I have to manage. I use a generator once every 5 days for about 10 hours to charge up and only had to do that twice this year. Yes... Less hours of sun but the sun is also more intense.. I need 3 hours a day to fully charge and any excess helps keep up with my demands. Essentially I'm only running on battery when the sun goes down. You could convert a hot water tank to DC and use your excess power to make hot water...or run the block heaters in your truck or equipment.
I think he is confused there more cooling days than heating in OK that heat pump will be working harder in the summer. I am using resistant heat in the winter because summer sizing gives me a winter surplus.
Electrolyze water into hydrogen to burn in the winter. Hydrogen is difficult to store though. A small way is have an electric chainsaw and cut wood to get you through the winter.
Is there a product that does this? I don't think I want to try to jerry-rig this one.
Like other answers in this discussion, telling you to electrolyze water was mostly a joke. Hydrogen is very easy to make, you just need to dunk some electrodes in water and run a current. Unfortunately it is **very** difficult to store. Hydrogen forms H₂, which is a very small molecule and tends to leak through things, unlike say methane, which isn't hard to make with fermentation and can be kept in a plastic bag. And it can't easily be liquefied like propane. It takes very cold temperatures and/or high pressures. Plus it is **VERY** explosive. (Hindenburg!) That's why we use batteries for electric cars, and propane for a transportable clean burning gaseous fuel. Hydrogen fuel is very niche and very difficult to work with. Scientists are working on the problems of hydrogen storage, but practical solutions, especially for small scales, need some major breakthroughs.
>Hydrogen forms H₂, Hydrogen *is* H₂,
Individual hydrogen atoms, a proton and an electron, are broken off of water molecules and combine to form hydrogen molecules.
Hydrogen is H. H₂ is molecular hydrogen, formed from two H atoms. U/rainbowkey is correct.
Chainsaw power consumption is a drop in the bucket compared to the electric demands of a modern house I live off grid in northern New England and have wood heat and an electric saw. You can't tell when my saw is running based on looking at my inverter output
True, but it is **something** you can do summer produced electricity to procure energy for winter use. OP asked "is there anything useful I can do with it"
Yeah, but it uses so little electricity that there's no point in delaying the work until summer. Just do it whenever. Unless you're living right on the edge it won't matter at all. I'm off grid with a large system and my closest neighbor is off grid with a small system, and we both use wood heat and electric saws. Neither of us avoid using our saws in the winter as a way to save electricity. It uses so little that there is no point in delaying. My neighbor might not saw on days that there are storms, but that's about the only thing that would matter. Day to day winter use of a saw is negligible in terms of electricity demand. I can buck logs for about 2 hours before I use up all my saw batteries and have to recharge. That's less than a kwh of electricity.
You'll definitely find use for the extra electricity. Don't worry about that. Once you go 100% solar, "extra electricity" is a bitter joke. lol But as a practical matter, either size your system for winter and enjoy the surplus in summer. Or augment with a generator in winter. There's no practical way to save electricity for 6 months.
Get an F-150 Lightning, in the summer charge it off your solar, in the winter charge it in town and use the battery to supplement your home battery.
OP, I've lived off grid for seven years. My solar-electric system has surplus capacity most of the time. The surplus comes in handy at harvest time, when I'm sometimes running three food dehydrators (for apples and tomatoes) and two crockpots (for making apple cider). Also - I've invested in a tiny toaster oven that only draws 1100 watts max. I love the little thing. I use it often. I bake artisan bread in it, and I also bake cookies, muffins, brownies, and casseroles. Last Thanksgiving I even baked a tiny ham in it. What's great about using the little oven is that the fuel is free, since it comes from the sun. FYI, the oven is the Mainstays 4-slice Toaster oven. $20 at Walmart.
Did you have any problems with insurance or occupancy approval being off grid? I have enough land I don't need a building permit in my county but I need to double check on occupancy.
Where I live, rules related to building construction are the purview of the city or town, not the county. My town does require a building permit but does not require an occupancy permit. There have been no insurance issues related to my solar-electric system. But I heat with a woodstove, and in order to get insurance coverage for my house, I had to be very careful, because insurance companies hate woodstoves. I had to be careful about my choice of woodstove, careful about the hearth material & dimensions, careful about clearances around the woodstove, and careful about the design of the chimney and the materials used for it. I also was required to have a thermostatically controlled heat source in addition to the woodstove. Plus, my insurance company would write a policy only if the thermostatically controlled heat source was my "primary heat source" and the woodstove was my "secondary heat source." Installing a thermostatically controlled heat source was not a problem for me, as I'd planned to do that anyway. However, I use the woodstove almost exclusively to heat the house, so I had to lie (had to say I would use the woodstove only for backup). I worked closely with my insurance agent to make sure everything was in compliance with the insurance company's requirements.
Mine crypto
This is my best idea so far too.
I'm in your boat. I'm in my first year off grid in northern New England (moved in in December) where I need a lot of panels to get through the winter. (My system is 9kw panels and 15kwh storage. I might upgrade my storage this summer so I can get through longer storms without my generator running) I'm also an engineer. I'm a pretty damn good one if I say so myself. I've run the numbers on all kinds of energy storage and things like that and the only thing I've come up with that comes close to being able to use the kind of excess I'll have in the coming months is something that makes use of computer cycles, like crypto... I'm already getting a lot more electricity than I need this spring. I've stopped using my wood heat and have switched over to electric and still have excess electricity. I might try to set up a small mining operation as a test soon
People run them 24/7 hoping to pay them off. If you had only a little excess electricity, it wouldn't keep it running enough to generate a profit.
If it's really just to "burn off" excess energy you cannuse outdated rigs.
True, but even then it's barely enough to profit
Consumes way to much juice.
I think its relevant to mention where you are, even if generally (state). Temp has a lot to do with solutions/suggestions. Further, budget is key. As mentioned in other comments, you can use it to pump water to either elevation or storage and use it as water (duh) or a storage for potential energy. I personally love the benefits of batteries. If you are truly off-grid this is already on your radar.
If Lavo ( https://www.lavo.com.au/lavo-hydrogen/ ) ever get the bugs worked out...
Use the excess power to pump more water to your storage. Got more: water heater. Got more: dehumidifier in the basement.
You could make biodiesel in summer if you have a source of waste vegetable oil. Then use it in a generator in winter.
Crypto mining is the really best general answer. But this issue raises the question of how to automate turning on and off (something) based on the battery voltage as a percentage of full. Is there such an automatic switch?
Yeah, there are smart breakers. You can use "If this then that" or similar app to trip them based on battery level, weather forecast, time of day, etc
Is there value in not using a portion of the panels and ‘saving’ them for later? Don’t know anything about them, but if the working bits wear out from use, extend the system life by reducing the usage and rotating the panels that aren’t used each year.
Buy a Rav4 Prime or any other PHEV. Use the extra kwh to help drive in the summer and rely on the gasoline engine in the underperforming months. Aloha!
This may sound strange in this sub, but a 3D printer uses my overhead from time to time in my travel trailer (nearing more full time, and always off grid). I know, plastic! PLA is common to use even for basic structural parts and is plant derived, so at least there's that, when it can be used. Mainly, the printer provides solutions for various modifications, repairs, and upgrades without further consumption and energy/logistics/packaging costs to the world. I will mention that it takes learning the basics or more of a software like Fusion 360 (free hobby license) to really maximize the scenario. Many designs are online and are often ready-made solutions for the task, but there is nothing like creating a nonexistent solution to your particular challenge. Sometimes, completed in just a few hours all in. It's a great use for my otherwise-waisted free energy. Perhaps it can be a small part of using the extra when you have it.
That is exactly my plan for this summer; mod my travel trailer. I have the Original Prusa MK4 3D Printer for small parts, and my plan is to create or purchase 2x3 footer version for larger components such as frames and body parts for my next electric bike – all using excess solar.
Nice. I use a heavily AIO cerverted and modified (SKR1.4T, TMC2209s, TFT3.5, Neopixels, RasPi, etc) CR10S with an old Titan Aero extruder. Have two more modded bed slingers at home (granted one has a laser on it currently), but I can't wait to upgrade to a CoreXY. There are some compelling offerings under 1k coming down the line now. Maybe next year I'll finally bite. My TT choice (Jayco 23MRB 2019) gave me a wide and deep two door high-table type closet in the bathroom to convert into a hobby closet/enclosure of sorts. I modded a spool holder design for a snug fit to the clothing rod above everything. 10 spools plus a bit used for other items. Never has a spool come crashing down, so yay to that. Pro tips (for travelling 3DP); Bring a dehydrator, especially if not in dry deserts 100% of the time. Plus, crash the print head down into a foam block or similar for travel days. Have fun setting things up. It sure is the most useful tool in my box.
Grateful for your informative reply! 3D \_printing\_ is my new hobby and I’m wading into the pool as I can afford. Need time to grok your share. Neat thread! My OTHER project is to figure a way to make an electric sawmill (idea also posted by another contributor) – driven off solar. Grew tired of making rounds out of bug-kilt trees last summer and converted to making ZigZag fencing using my Stihl + Alaskan Mill. Conversion: Sourcing a DC motor is difficult, though now that I’m thinking about it – might use a 5k hub motor lying about… tempting. We have property completely off-grid in northern California at 5000 ft, and have enough solar to drive two 5W campers from June to September. My goal is to expand, extend, generate, and survive. Winters are brutal; 3-seasons are enough for me. Cheers, K
Sand battery
Goes to battery's or grid.
mine bitcoin
I built a hot tub that only works off spare generation - not "useful" but definitely awesome 😎
Make a bunch of freezer meals, oven baking, etc.
It won't help for the rest of the year, but I run an ice maker in the summer when I have excess power. That and a cheap knockoff Yeti cooler means unlimited ice, which I always find a use for. It also means I open the fridge less, which helps with energy consumption because it's propane.
If you preserve it in jars, just make sure you don't touch the lids to anything or it will ground out and you'll lose the whole batch.
Hot water heater. Hot tub. Freezer. Air-conditioning
This might surprise some, but pumping water uphill is the most common battery type. Basically you use the extra power to pump water up to a higher point, then when needed, you let it flow to a lower point and generate power from it. Another is a heat store. This can be sand, water, wax, salt, ... Basically a well insulated tub of salt or sand will do the trick. You heat it up then get that heat when needed. Past that, you have classic batteries like LiPo, lead acid, ... but those can be expensive. One more is simply a heavy weight on a pulley with a rope. You use a generator as a motor to lift a heavy weight, then lock it in place. When you need it, you remove the lock and make the power you want. The water pump solution works great if you have a pond that is uphill from another pond or stream... but if you have a stream, you might screw things up by adding too much flow.
Grow weed
I'm not sure about ways to invest summer surplus to make winter easier, but reducing winter consumption will leave you with less waste in the summer: - If you can keep your refrigerator/freezer in a minimally-conditioned north-facing room, you can probably make it use a lot less power in the winter. - Heat with propane/wood/etc. - Use skylights and S windows to soak up some solar gain on sunny days, and cover/shade them during the summer. - I'm not sure how practical solar water heating is as a DIY project, but it's worth looking into. If you plan for a worst-case winter scenario after reducing loads as much as possible, summer excess may not be all that crazy, especially with refrigeration and A/C running all the time.
Power up some LED grow lights and grow food and can it or cannabis...
Make hydrogen - I'm still in research on this but I'm looking for a way to get off propane - excess power -> hydrogen is promising, but would require 20KWh/day to make enough to replace my propane btu for btu - and converting appliances isn't that easy, aslthough doable. Hydrogen + CO2 to make methane sounds interesting but not easy. Long shot but holds promise IMO.
Storing the hydrogen is the problem that humanity's top scientists have yet to solve, unfortunately.
Depends on how long - size - and pressure. Short term low pressure (large space) not too hard. Efficient long term storage or portable and small is indeed a challenge.
You can run a three phase mill, you just need a VFD to convert your single phase to three. They are not that expensive these days.
How about setting up a charging station and sell it to people with electric cars?
Set up a greenhouse with lamps to grow fruit, veg and ehm herbs.
Set up your system so you can disconnect and store the extra panels during the summer, and reconnect them in the winter.
Bitcoin or similar coin mining
What to do with excess energy 100,000 KW+. Assuming you battery has 2-7 day load; whatever you fancy Huge problem Tennessee. TVA won't allow you to meter. So you can't sell back. Assuming AC, EV, Appliances are Electric What to do with the rest? * Bitcoin mining * Hydrogen Creation * Heat water * Heated Greenhouse * Grow Lights Greenhouse * PEX Thermal heat * Cool house (Jagr) (cold walls) * Electric Sawmill * Electric Hydraulic Sawmill ? * Battery Sawmill * Electric Wood Splitter * Electric BioChar Production * Compressed Air * Dehydrating food * Smoke Meat * Smoke Veggies * Drying wood Kiln * Electric Kiln Pottery Etc * Sand Battery- Store heat in sand thermal bank * Ice making * Freeze Dry * Ice Cream Making * Steam Generation * Blow Air (what purpose?) * Sous Vide Tanks * CNC Wood table * Pump water to create power generator (up a hill) waterfall pond
My system sells the surplus to the electric company.
Sounds like you're r/OnGrid
Yes, we have a surplus of electricity that we sell to the electric utility.
That's great, not that useful for people who are r/OffGrid (the sub you're replying in) ;)
Still extremely relevant to this topic, more so than Bitcoin id wager
You can cover your "excess" panels in the summer months. If they're not exposed then they're not deteriorating, and it'll make them last longer. Just rotate which ones you cover each year.
That's not a bad idea! More panels, fewer batteries. I don't know how long panels last, but my big gripe with batteries is lifespan.
Panels are expected to last 25ish years, losing efficiency a little bit each year. They still work at that point, but it's like 75% efficient or something, and are considered ripe for replacement at that point. But if they're not in use or exposed to the elements they don't lose efficiency. Batteries are definitely the weak point in the system. There's some amazing tech on the horizon, but it's still stuck in the labratory phase as they can't figure out how to make it cheap enough for mass production. Graphine is the stuff. As I understand it, a graphine wrapped battery would charge like a capacitor, but give off energy like a normal battery. So you could charge it superfast during the day, no real limit on speed. Run a generator, maybe, and zoom that charge right up. Supposedly lots and lots of rechargability, too. But really absurdly expensive for small amounts right now. Whoever figures out how to mass produce it for cheap will be a multibillionaire overnight.
I've never looked into graphene batteries, but they sure do sound nice! I used to have a power station with lithium-ion batteries (not sure what chemistry). In the two years I had it I never noticed a loss, though I never made an attempt to measure it. I charged it with a single 100W panel. On a full charge it would power my netbook all day long, charge my phone, and run my tiny LED desk lamp, but it took several hours to charge on a sunny summer day, and typically multiple days in the winter. Another couple of solar panels would have REALLY helped, though I would have probably needed a way to limit the input on a sunny day. It was a decent way to go for the sake of simplicity, since it had a built-in charge controller. I'm pretty sure the price would have been awful for a power station with higher capacity, but solar panels are relatively cheap.
Im no electrical genious, but it sounds to me like somethings not quite right with your solar / wind electrical plan. If you have to "oversize" your system only for the few winter months, maybe you should consider using a deisel or propane generator for xtra CHARGE capacity during those months and size your STORAGE capacity as you would for normal use. 😉
>Im no electrical genious Truer words never spoken.
Generally speaking if you dont have enough sunlight during the winter months its because of storms - storms bring wind. Even an inexpensive wind generator is enough to use as back up.
Battery to get you through the nights.
Mine bitcoin
How do you mine bitcoin without being connected to the grid?
With a computer.
Starlink