Sand Battery Heater solar powered 250F / 120C with no flames or fuel! DIY

that is a really nice demonstration mate - loved the video - cheers

When was the last time you saw 250°F water? One BIG benefit of sand is that you can easily go FAR above water's boiling point without a pressure vessel, giving you a way to offset the difference in heat capacity. Imagine 1000°F sand!

Don’t ever stop teaching YouTube. Bought you a coffee because you are detailed, don’t waste time, and know how to state your theory or intent right up front.

Good DIY demonstration of a sand heat battery. As you said water has a higher specific heat capacity than sand approx. 4200 J/kg/K to 830J/kg/K about 5 times. So 25 kgs of sand heated up by 500 Deg C would store 830*25*500 = 10.3 MJ not a lot, but the great advantage is it can be easily scaled up. Great video.

You miss one point. But it’s otherwise a perfect demonstration of the principles of sand batteries. The purpose of making a battery is to store energy for you to use later when you want to use it. So putting in an insulated container is how you retain the heat for later and pipes would allow you to extract the energy when that time comes.
Nice vid.

you could wrap that pot with copper tubing to make a fluid heat exchanger for haeting a soaking tub, radiant floor heating etc

This is such an awesome project. I have no need for it but I want to make one anyway. Thanks for the video!

Excellent! Simple, straightforward. Your right. Unnecessary complexity reduces cost effectiveness. You cant make energy, you can only move it.

I am probably going to try a similar experiment for this coming year (2024). Of all the questions and suggestions I’ve seen here, no one seems to realize that water can’t be heated above 250 degrees F or it just boils away. But sand can be heated to 1500 degrees F! I’m thinking I can build an insulated box outside the back wall of my 12x12 greenhouse to contain the sand battery, let it charge all summer long, and direct-connect the battery to the greenhouse with an insulated 3 or 4 inch PVC pipe. There would be a small fan that would turn on when the greenhouse inside temperature drops below 50 degrees and off at 70 degrees to recirculate the air from the greenhouse around the sand battery to reheat the inside of the greenhouse. The battery would certainly lose heat during the winter but it would still recharge during the day whenever the sun is shining to create the electricity for the heater element. Plus it would amass all that heat throughout the summer months and begin the winter with a surplus amount of heat energy stored in the sand. By the end of the winter I’m sure there wouldn’t be much surplus left - if any at all, but as the spring moves into summer it would start recharging all over again. I just want to keep my winter crops from freezing. I’ll have to see how this goes. I may need to have more than 1 or 2 batteries to make this last, but once I’ve got the numbers down it’ll be free heat all winter for my greenhouse. See “Polar Night Energy” for an example of how they are heating homes with a sand battery. Of course it’s just a matter of scale. My challenge is to find the right scale for my 12x12 greenhouse.

I love the physics you use and explain,easily understandable to anyone. From "the physics professor"

Love this idea, I will be doing this come fall..

Hi thank you for that.
It is good that you show us how to do it, however. I have been using immersion heaters as dump loads. To control our wind turbine.
Over the years we added 5kw+ of Solar pv. The base voltage is 120vdc and the Dump load voltage is 138/9vdc into two tanks total capacity is 500ltrs +, each immersion is 2 kW. They are stepped to brake the WT seconds apart. It works very well with no problems since its installation in 2008.
I would not dare tell you what to do but an accumulator of capacitors or batteries would give you a much better power range.
You were working in the full Power of the Texas sunshine and if your sunshine range dips to 66% you will get no heat. With capacitors or batteries or both between the panels and the sand battery it will produce much more over a longer period.
55 years ago, they installed storage heaters in our dwelling houses. Some were 3jw..
They used economy 7 to heat the elements but the material used to store the heat were canisters of 4mm limestone chipping., dust free. 3 canisters approx 200mm in width sq and 500mm in depth. Made up a 3kw unit. Later on they used a fire brick of sorts.
This is a much discussed item in renewable energy forums.
Keep up the good work.
Cheers.

This is cool! Thanks for sharing.

Nice proof of concept.

Thank you. best and easiest demo.

Excellent! I would just put some fence around as a shield so not hit the hot pan by accident. I think if you can build a simple insulated box to put it in and out, it can hit peak temperature much faster. A smaller version with an insulation box would be great as a camp tent heater, where need less power from a smaller more portable panel, and will only use the heat at night. It's so simple any camper can do it!

Neat idea 💡

Love it brotha thank you for the update but believe it or not i do heat my house with sand in mass so we get very cold i see your points and i agree i have alot more solar then you have available along with the cost is alot higher then you spent but with higher capacity of weight comes more capacity to hold the pipes at 230degrees i really woukd love to send you out our sand battery to test and pick apart i could even come down with my campers sand battery and show you also im retired and my business partner does awesome so i could take the time away i have many friends in texas

Thanks!

good project