Off-Grid DC Power: How to Use and Store Solar, Wind, or Hydro Energy Without Batteries

I'm working on an off-grid homestead and exploring how to use DC power in ways that align with permaculture principles—low-tech, resilient, and non-extractive. Rather than relying heavily on conventional batteries (which can be expensive, short-lived, resource-intensive, and lets face it - in the long term add toxic gick), I'm looking into creative ways to use energy directly and store any excess into the natural system in ways that it can also be tapped into when needed. Think thermal mass, gravity-fed systems, water pumping, compressed air, flywheels, or anything else that converts into useful work without the battery bottleneck. What has worked for you? I'd love to hear real-world examples, ideas, or even failures that taught you something valuable.

Sand is good for storing heat, if you insulate it right, the heat will last forever. I seen a clay battery on YouTube using zeolite.

If you have steady running water, rig up some pipes and series of low voltage fans and you have ac for heat.

For water, there's ram pumps, and trompes.

If you build a giant circular funnel shape for a stream of water to fall into, the air will mix in the water, then on the bottom of that funnel you elbow a pipe out and up to go above the height of where the funnel is, a few meters higher. Now your mix or air and water has gone up higher than where you water came up. That's how they pumped water up the hill. They call them airlift pumps or trompes.

You can also make ponds and have bell siphons. Get creative.

I have experience with gravity and solar panels. But I used batteries.

There's also earth batteries.

Compressed air in storage tanks.    Amish use this,  one bought a rail road car, filled it vial compressor with air, then ran all of his shop and home with the compressed air.


Gravity Batteries.       Power plants will take excess energy and pump water to a higher level,  then when needed use that water with water turbines to make electricity.      Other variations is rail cars sent up hill then released with regenerative breaking  to charge batteries which are then charged by the time the get to the bottom of the hill.

Storing energy in ice or heat...        I have a thread here about sand batteries...


Storing energy chemically.       Some reactions like with limestone energy can be stored,   then released by adding water.

Storing energy organically.       Alcohol can be produced from sugar cane or potatoes,    then run in engine .    Engines also can run off charcoal / wood.

This said,   Lithium batteries still are chosen because of the percentage of energy in verses the energy out.        They are very efficient at the task they do than the other alternatives that I am aware of.

You can certainly find solutions that will work, however nothing will work at any reasonable scale to power a home.

If you're just looking to retain a small amount of electricity to power something minor for a few hours that might be doable, but without modern batteries you won't be able to power a whole house when the electricity goes out for any reasonable amount of time.

Gravity batteries work but the amount of water you need to store is insane when you do the actual math. Any type of thermal battery won't work any better than the gravity fed ones as far as I know.

You can try to store it chemically but it's just going to be a much worse version of a typical battery.

As the poster above noted, you could also create alcohol do something like silviculture to make charcoal / wood. Those are good options because theoretically you can store a large amount of power in a (relatively) small area. The problem with these two is producing enough of it, but at least they store nearly indefinitely and over time you can continue to stockpile alcohol or charcoal for an emergency.

You could also theoretically split water into oxygen and hydrogen with electrolysis and try to store the hydrogen, but finding containers that won't leak is very difficult and it can be dangerous, because to store it at a reasonable density it needs to be under tremendous pressure.

Well some traditional ones in the off grid world are:
-Over sizing a pump pressure tank so you have running water when the sun goes down. Instead of a small pressure tank that actuates a pump regularly you have a very large tank that runs a pump hard when the sun is out then you coast at night.
- replacing a hot water tank element with lower voltage elements that run directly off of DC so you have a supply of hot water at night. You turn it's thermostat up as high as it will go and add a cold water mixing valve after the tank to regulate the temperature coming out.
-freezing blocks of ice during the day to create cooler blocks so you can refrigerate without electricity at night.
- smaller air con units that draw down room temperature during the day so you can coast at night.
Now having said all that the conclusion most off grid people have come to is incorporating a small battery element solves a whole host of problems and simplifies the system. All of those DC power users listed above require resources knowledge and time and are less resilient and efficient than a battery element. Lead acid is short lived but fully recyclable, nickel iron is an extremely long lived non toxic option that is recyclable, and lithium is a 10 year plus battery that is recyclable though not currently fully recycled due to how new it is. Ultimately it will depend on the level of energy you are comfortable with in your life. They are questions only you can answer.
Cheers,  David