1752 A DIY Sand Battery - The Theory, Practice And Use

After we saw the giant Finnish model, we built a sand battery for our bus-turned-tiny-house since propane heating gets expensive quickly, wood burning presents issues with ventilation, and we always have more solar power than we have use for. Currently I have the battery set up to be plugged in and turned on/off with a cheapo Christmas tree foot switch, and it's been wonderful and so much more efficient than I could've possibly imagined. A single, tiny space heater will drain our +300ah battery bank in a matter of hours, and all that heat disappears the second it's turned off. With the sand battery, though, we can leave it on all night, get the bus nice and toasty, and for upwards of 5 hours after it's been shut off we can keep the bus warm and cozy, and all without making so much as a dent on our battery bank. On top of that, should we get a week of rubbish weather where we're not getting a full recharge on the LiFe batteries, our baby alcohol burners under the battery heat it up just as well and, again, at a fraction of the price of propane. I had the same idea to use a series of peltier devices to reclaim some of the heat energy and put in into a heat dump for our hot water. Still need to sort out the logistics of that project, but we've been wonderfully pleased with our sand-in-steel heater. ^.^

We did something similar in a college physics class. The class built it with salts rather than sand. We heated the salt until it melted then placed it in an insulated container. I believe it was epsom salts but can't remember for sure. It stayed hot for days. We slow cooked a ham using the residual heat the next day. We had a lot of fun in that class. Do your research on safety folks. Notice Rob is using kiln dried sand. If it is not properly dry moisture will come off of what you are heating, therefore do not enclose it in an airtight container to heat it. It might build up pressure otherwise and might rupture or on cooling collapse your vessel. Rob's playing with fire video applies to all things, not just fire. I really enjoy these kinds of videos. Thanks Rob!

I've always liked the idea of using crushed glass that can't be recycled in a sand battery. It's not just free, some places will pay you to take their waste glass. You can guarantee that its chemically pure and inert, and you'll comfortably be able to heat it up to 1500K if you want without any volatility. It ticks all the boxes of clean energy storage, simple, cheap, reliable, and doesn't require raw material mining.

This video Sir is exactly why I've chosen to support you vs other youtubers. You seem to have a genuine desire to help your fellow man and are a great educator as well. As of late I've seen more videos concerning sand batteries being produced. Lots of folks are starting to experiment with different approaches to this fascinating topic. Might I ask Sir if you could possibly explore this subject further. There's not a lot of material out there yet and a collaborative effort might defer the time and cost of developing a turn key system. Thanks again Sir, Daniel Pattison

I've been watching your videos for some time now. I live off grid and the things you teach and demonstrate are amazingly useful to my lifestyle. I am going to try this out as a heater for winter in a 55gallon steel drum with copper coil to run water through. Ofcourse this will be a all around water heater as well not just for room heating. Thanks for the great videos and for teaching me so many things. I also may throw in a peltier or two to generate some electricity as well since the surface area will be substantial. Thanks for all the videos! 🐅

A friend of mine is a potter, and has a tiny wood stove COVERED (and surrounded) by various clay pots and vases. It acts as his heat battery and radiator. (Don’t set a room temp clay pot on a hot stove, or dump water into a hot pot- heat shock can cause the pot to crack or explode). It works well.

In steam trains, they used sand boxes. One use was to sprinkle some sand on the track as required to increase grip. The other was to heat sand which would be distributed by the "sandman" to replace the sand in the cabin heaters for the passengers. The Seekers' song Morningtown Ride mentions, "sandman swings the lantern to show that all is well".

That practical use part near the end of the video puts the sand battery in to full perspective. Anyone who wants or is thinking about going off grid. There's your much cheaper way to store your energy and or excess energy. This would or should last a lifetime or possibly many life times and would be far far cheaper and easier to maintain than normal batteries. Thanks Rob ! 👍

Heres an experiment to try; I once made a battery out of (Sodium Sulfate) , i would heat up the ( Na2SO4 ) crystals till they melted into a liquid... then the liquid could be stored for many , many days; if you discharge an electrical arc (such as from a gas fire pit piezo) , the arc will begin a reaction where lots and lots of heat is given off as the liquid then returns to a solid crystal again; this process can be repeated ; over and over... a great battery. Thank you Robert for these videos to keep our minds sharp.

I'm inspired by your videos, so I bought myself a bag of fine sand today. I have (and use) a coal and wood stove, so tomorrow will fill up an iron kettle with sand and put it on the stove. Once the stove cools down, I will put that kettle under my chair 🙂 I hope to get some radiant heat from it.

Some of your videos are just completely ahead of the pack in terms of their long-term impact and I really think that this is one of them. Thank you so much for making this, Robert.

Very interesting. Had not given this a moments thought. Thank you. Sand is abundant and cheap to free. Glass beads like this used in industrial blasting cabinets are an option. Almost everything presents some potential hazard. We just prepare for those we know and pray for divine intervention for those we don't

Hi. Love your direction. I have an old hot water heater that rusted out. Will not hold water but will hold 50 gallons of sand and comes complete with heating elements. I see a few ways to use it with your ideas. Keep the great ideas coming. Your an inspiration!!!

Hugely valuable lesson. Ohms law in plain english, with an understandable example & a practical application. Robert Murray-Smith, thank you. my brain -Thanks you so much. sweeping away the fog of a failed education 1 video at a time. I really like the diagrams you flash up. I pause the video and have learned so much from some of them & you don't over show anything. good on you.

Thank you Robert , you are so helpful in explaining subjects . I will always watch.

I just love your videos! I just had a thought about making a cheap sand battery. Just get a kitchen oven and fill it with sand, use the elements you get from it. Use the switches to control it. Put it on it's back. To let the heat out open the door. Its already insulated to 500 degrees if its an old self clean. Just a thought. Please keep up the great content!!!

Your channel has been a great source of inspiration for me and my family boy 6 year old son is very eager to attempt some of your projects I also couldn't help but think of connecting your ingenuity with the need in Ukraine going into this winter The rocket stove married with the hot water could could literally be a life saver.

Just simply friggin inspirational, there is so much we can do with this, like heating homes for the winter, I'm planning on something like this

I love how informative and personal your vids are, I feel like I'm hanging out with a friend building random stuff in the garage for fun. I love it

Your channel is fantastic! I built a 4-ft x 8-ft solar air heater that gets up to about 250F on a clear sunny day here in Texas. I also built a 4-ft insulated sand battery cube that has an "inner air coil" of 4-inch aluminum flex duct , and an "outer air coil" with about a ton of sand all around and in-between the air coils. Using a solar panel and a battery and a 12v marine bilge fan, I've been blowing hot air into the inner coil in tests and have been able to heat the inner core of the sand battery to over 100F using only solar heated air and solar-charged battery power. Can use the outer coil with another fan to take heat out of the sand battery into my shop! Next, I'll be adding a 12v resistive heating element to the system to see if I can get the internal temp to about 200F. Thanks for all the ideas!