1607 A DIY Sand Battery

[@PaulSmithGsy]

Thank you. I'd been reading about these in the news recently. Your enthusiasm and humour when presenting your videos always gives me a lift. Please don't ever stop.

[@ThinkingandTinkering]

oh wow cheers mate

[@StirlingLighthouse]

To me, rocket stoves were made to be used with mass heaters. Run the exhaust through a thermal mass. Sand, dirt, bricks, clay whatever. The heat coming out of the chimney is very little. Letting the heat go straight up the chimney is a total waist of fuel. Paul Wheaton has been on the forefront of rocket stove mass heaters for decades. His results for reducing fuel used is impressive. And the time to burn is minutes instead of constantly burning all day as with conventional wood stoves.

[@ThinkingandTinkering]

for sure mate

[@ronroberts110]

Yup! I agree. Read up on Russian stoves, Finnish stoves.

[@RareVBlue]

My entire rocket stove is homemade out of clay, brick, sand, and the chimney piping. I can burn a 5 gallon bucket of wood in the winter with it being 20 degrees F outside and I'll get my tiny home heated to about 85 by the time the fire dies down. But the residual radiant heat trapped in the clay and sand form of the stove that it'll keep it warm all night and it'll be about 65 degrees by the time I wake up.

[@thechumpsbeendumped.7797]

Waste not waist. Other than that I agree.

[@justtinkering6713]

@@RareVBlue put up a video

[@williamkain7414]

Seeing you heat that water so fast has inspired me to replicate this immediately. Really love your work Rob. Your delivery is why people love you. Thankyou very much!!

[@yellowbird5411]

Back in the day, a couple of centuries ago, rocks were heated by the fire and were put into metal buckets or containers and used to heat certain areas, like under the seats of carriages, in bedrooms, or wherever they were needed. Today, rocks are used for heating tents in camping, and they last a long time. I had started wondering about sand, as I live in Florida, and we don't really have rocks by the beach, just limestone, but that's kind of further inland. We are on shale here. So I started looking up sand as a heat-holder, due to the fact that I didn't really want to buy some rocks, as they are expensive, used mostly for decoration in front yards, or fire pits. I was pleased to find that sand does indeed hold heat extremely well. The sand we have is mixed with organic debris, but it can be cleaned - I have done that a lot in making some homemade fertilizer. Pure white sand is the result. We have power outages here once in awhile, but being in Florida, heat is not too much of concern, as our temps stay pretty moderate most of the year. We don't see freezing too often. Daytimes can hang around 50 or so in the winter. But putting a bucket of hot sand from a fire pit in the yard under my chair could be a warm welcome if the electric goes out in the wintertime.

[@malcolm8564]

In Germany and Scandinavia it's common to have a wood burning stove surrounded by a lot of masonry as a heat store.

[@jasonlongsworth4036]

That used to be the case in cities, but it's only true for the countryside these days

[@wkinne1]

Here in Michigan there are thousands of old silos on farms no longer in use, imagine filling one with sand and putting solar panels every few feet surrounding them from top to bottom. Have some heat generating resisters in the sand and you have a massive sand battery! I only wish I had one 🤔🤔 Spray foam the inside for insulation, sure seems like this would work.

[@ThirtytwoJ]

Or lqryer it into cells and use as a earth battery

[@billyjones9045]

I'm a urethane foam sprayer. That's a great idea. You could spray the outside to and coat it and or wrap it with lath and trowel something over like clay or stucco

[@billyjones9045]

@@ThirtytwoJ what does layering it into cells do? I'm pretty new to this and battery and I'm trying to figure it out

[@ScoobyD2]

If sand retains heat...then ...why do deserts get cold in the night time ? 🤔

[@XiaolinDraconis]

@@ScoobyD2 because it's not insulated and has cold air rushing over it.

[@WileHeCoyote]

I love it Rob!! I've thought about making a sand layer with a steel jacket around my existing wood stove just to remove hotspots, (I have clumsy oblivious dogs 🐕 🤣 I had wondered about the thermal battery value of it, so this encourages me immensely! Thanks Rob! You're one of the greats!

[@ThinkingandTinkering]

cheers mate

[@johnsmith-000]

Great video! I think it would be interesting to find a simple way to utilize the sand in situ with minimal expenses. For example, if you want to install a solar cel array in the desert, dig a hole in the sand, throw some kind of lining and spray insulation, put whatever is needed in the hole, like pipes for medium circulation, push the sand back into the hole, and insulate and cover the top. Of course, what exactly should be used as the lining and insulation is for another debate, maybe just polyurethane foam and metal plates, or concrete, but in any case, if it would work, it would make possible to transform Sahara into a giant battery in no time, and would also have near zero impact on the environment. In fact, if you put dunes back in place carefully, none would be the wiser LOL.

[@shortbuslife3440]

Well done Rob I like the design, I used granite stone chippings but I like this solution as it's all nicely contained, my only concern is the potential to melt the firebox as sand is also an incredible insulation and mine glows bright yellow when it's been running for a while. Spalling may also be an issue so check inside occasionally for the metal flaking off but the thickness off pipe you're using you shouldn't have an issue.

[@originsdecoded3508]

How fine do you get the granite stone chippings?

[@shortbuslife3440]

@@originsdecoded3508 just loose chips that you would put in garden I think they were probably around 30mm long at most, so any loose stone will do from chippings to sand

[@originsdecoded3508]

@@shortbuslife3440 WOW! This Comfirms What i've suspected long time ago regarding some ancient archeological discoveries near Angkor temple complex by the Sra Srang basin in Cambodia. They found hundreds of of clay shaped turtles burried into the ground with pure quartz crystals tightly packed inside, and all them connected with metal wires in series. Seems to me they were utilizing the same concept you are describing here. They were using pure Quartz crystal instead of sand. I imagine the sun would heat up the clay turtles, heating up the crystals inside, and you know the rest. The ancient Past was not primitive at all!

[@loricampbell4174]

thanks for this. I was going to put a smaller canner full of sand on the wood stove but maybe a chunk of concrete will work just as well, less mess and adjustable since there are a few of them around here. Should be able to let the fire go out at night.

[@frederickwood9116]

I love the little Humm uttered as you stated to put the sand in.

[@markbothum4338]

I live in Alaska and heat the main living space with a home-built woodstove. It's a horribly inefficient design (basically an old propane tank with 3-inch pipe for a chimney) that sends most of the heat straight up the pipe and out. Now you've got me thinking.

[@ThinkingandTinkering]

awesome mate - cheers

[@aether-elephant]

You could wrap copper pipe around the flue and take the heat anywhere u like from there Or get a fan?

[@suzannehartmann946]

The Romans ran a pipe beneath the floor of their homes. The fire was on one side the pipe ran slightly uphill beneath the floor warming the floor and the home. Smoke escaped the pipe the other side. Add sand or water on either side of the pipe to retain and radiate the heat and you have a more efficient system. Run the pipe back and forth (left and right) as you see in old indoor radiators (hot water pipes with radiators in individual rooms for warmth) but instead of running hot water up and down you run the hot air back and forth through sand (water will eventually rust the pipes) and you would probably have a great system. It would also prevent smoke entering the home though cracks in the pipes. Having a furnace beneath the home was common in places with basements in eastern USA where feasible. Florida not so much.

[@ballaghbotanicals]

Look at rocket mass heaters

[@patrickmcginnis7]

There was a guy in Ukraine putting videos on YT of his Fresnel lens heating solution. Although I knew someone who used a similar tactic by heating rocks during the day, and then moving them inside at night in the mountains of KY. So unless you are in the dark, u can make heat on cold days passively. Sometimes simple stuff like putting a radiant barrier in your attic and/or making sure there is a jog in your exhaust pipe can keep what heat you do get inside. But I live in Fl, I have a fireplace which is surrounded by rock ... so that one day a year I do use it... it stays hot/warm for 12+ hours or so after burning. yes, most of the heat escapes. but the flue column surrounding the pipe also is a contained air gap, I could steal heat with a small fan to reduce cold spots in the room ... but like I said, I don't need it. Personally I'd try a closed loop of mineral oil, although i know nothing about how to passively pump it into a radiator. glhf.

[@Milkybar3320011]

I can see this simple thermal store being ideal for narrow boat as a flue to outside is simple to achieve and they can get very cold during the night, the weight wouldn’t be an issue either being fixed and could form part of the ballast. Add a couple of peltiers in the right places and you’ll get a bit of continuous power. Now I just need a narrow boat 😆

[@misamsung6191]

put a coil of steel pipe inside the sand, a small pump to circulate some water and you have a circulating hot water radiator for your narrow boat. Just the thing for those cold nights on the cut. Seems that you and I are missing one important thing to cruise the cut, that pesky missing narrow boat. LOL

[@ThinkingandTinkering]

it would be ideal mate!

[@l0I0I0I0]

I love what you made there. It would be most interesting if you filled the bottle as you did, BUT put a stainless coil inside to draw out the heat with water as needed.

[@klauszinser]

I was thinking of moving the hot sand around. For steel 1000°C should be possible. So you would have a well insulated box and you cold take the heat out. But then, why not having a steel pipe and blowing air through. And rotate the box if needed. But whats the difference to the electric heaters in the rooms which were heated up electrically by night and where the heat was taken out over day. Whats good, desert sand (that cannot be used for construction).

[@l0I0I0I0]

@@klauszinser At that temp, you could cook your food as well and create a convection oven using a fan, or even an air fryer. Air may prove to be better than water for removing the heat though water is better at storing the heat at lower temps below boiling. Perhaps a hybrid system where the ultra high temp material is left outside and pumped via air into living quarters to heat water below boiling to provide heat where needed over time as water is best at storing heat at lower temps. You still need to insulate the water so the heat does not dissipate to rapidly but not to much so it provides heat. Then you can use the hot air also for cooking, and in my case, experimenting with other projects and perhaps a pizza oven! 🍕

[@StratRider]

something similar with copper coils inside and a fan to force air as a way to distribute the heat further away as into the interior of a house or another room would also be interesting.

[@ThinkingandTinkering]

for sure

[@Goody2shzToo]

@desertsun02 has some videos where he does just that.

[@agritech802]

Thanks for another great video Robert, this is something I'd definitely like to try myself, it could be used for simple home heating or in some industrial applications where a lot of heat is required for certain manufacturing or chemical processes. Could you do one or two videos that would demonstrate 1. how to heat the sand to 500 degrees using a heat pump and 2. what type of insulation would be appropriate to keep in the heat for as long as possible as they have done in Finland? Edit: I see you have answered the insulation issue in video 1622, you must have read my mind 😁 Thanks a million!!

[@onegreenev]

I remember reading an article long ago about a cinder block container filled with sand and a fire box was built into it as well as copper water coils throughout the sand. The whole little building was just a box filled with sand and a fire box. The copper tubing ran from the box to the house and then they would build a fire in the box and just crank it up then let the fire die out. It would give in the dead of winter a good two to three days of comfortable heat to the home via a hot water system that also heated up the water for hot water for the home. The heat was not drying heat. During the summer you would not need that heat. When you did need the heat solar would not be viable because the weather was not producing enough electricity. Some days maybe. But if you have wood or some other source of burnable material you can have good heat through out the winter. May need to figure out a good way to do the solar or incorporate solar heat and fire box or some sort of natural gas for those with natural gas.

[@alfredharrison597]

Put a copper coil tubing surrounded by the wet sand that you heated up (inside the heater) and the copper tubing going to a radiator inlet and outlet. Much like a pass through system. Fill the radiator up with antifreeze and make sure there are no leaks. What this will do is circulate the hot antifreeze inside the tank with the wet heated up sand outside and that circulation will keep the radiator heater heated all night long. I watched a guy do this in alaska where the temp outside was below zero and it kept him warm inside his little shack he build comfortable all night long. He was very far from freezing to death. He had his heating unit sitting outside in a campfire but the same premise applies here also. Can also use an H2 burner (if youre living off grid and doing the H2 generation thing) to keep the heater warm, much like a gas-powered hot water heater.

[@abittwisted]

@@alfredharrison597 How would you do the H2 production efficiently off grid? That takes a whopping amount of electrical power to produce dangerous H2. Just use the electricity directly to heat the sand for evening use. But you’d still need alternative forms and ways to heat the sand as solar may be obscured for days, weeks at a time. Combustibles are the option. Producing H2 is not efficient on a small scale. Why waste energy. I’d say for off grid, build a solid solar array and us battery backup and build a solar reflector to heat water during the day and pump that into your sand through copper pipes to heat the interior and have a huge sand container with plenty of piping.

[@21stCPH]

Great idea!

[@smartcookie11]

So your saying you should run hot water into copper wires to heat up the sand???

[@smartcookie11]

​@@alfredharrison597can you refer the guy from Alaska

[@leegosling]

Clam bake! Gotta love the old tech. Loads of potential as new tech. Good work Sir.

[@ThinkingandTinkering]

absolutely mate - cheers

[@DavidPaulNewtonScott]

Two points this would be exellent as t tent heater no worries about fire in the middle of the night. I am back in Portugal working on my house and I have noticed that the sandy rock in my area is very high in iron. Night storage heaters are basically fuse iron oxide bricks. So I am going to give this a go with our local sand. Try adding iron oxide cement dye to your sand it may help with the absorption of the heat charge.

[@TheGijzzz]

Can you combine this with solar panels and electrical heating? Im sure a lot of us would want to see the first low cost diy home build solar sandbattery

[@vladimir7370]

this is the channel for me.. so many interesting innovations.. thank you very much master

[@Paraselene_Tao]

This video is particularly interesting to me because I've been sitting around imagining a "fix" to the battery storage problem that solar panels have (which makes them an intermittent power source at the time--sun goes up, sun goes down kind of issue). I imagined thermal batteries as a solution. I was thinking something awfully expensive like molten metal at over 1000 C, but it's nice to see we can do the same thing by principle with sand or whatever earthy materials we have laying around. Plus, a lot of metals have lower heat capacities than sand. Overall, this video is great. Thanks.

[@smartcookie11]

If heating sand has a high half life and retains heat really well, then surely heating sand must also be much harder than water. Then why not directly heat water then.

[@robbiearlenewasley4586]

This got me thinking to load up a couple of large tins with the fine New Mexico dune sand where I live, and placing on my wood stove when I use it. Tins would store the energy just like this battery.

[@kevinwest7829]

Paul, I've been watching your channel for a short time, I love the content. In regards to the sand battery idea, I'm thinking about using a magnetic induction coil to heat the sand a bit quicker. I'm just a thinker on many subjects and certainly no scientists. I would love to see the possibilities for this idea though. Great show and quite addictive 👌

[@radiweldu1052]

Thank you But How can we extract the heat and use it for other purposes???

[@markusgarvey]

You just gave me a great idea. Thanks again Professor. I have big dirt and rock berms on my land, mostly clay. (I have a lot of very dense basalt rock on my land. The clay relatively fresh volcanic ash, with not much else) The rock is so dense, you have a hard time breaking it w/ hammer and chisel. I am a Mason as well, so I know what hard is. Rocket stove, still heating water heating, w/ pipes coiled in the berms. I can add sand where I excavate for the water line. I will also coil the lines under my floor and run a small circulating pump when there is no thermosyphon. I live off grid, and I have to run generators during our really cold winter, so I am gonna capture all the exhaust heat with a heat exchanger, and put it in the system. Win-win. I always think about all the energy wasted from exhaust heat. Now to figure out how to use the heat to cool as well. I will send you a video. I wonder if the rock has has a good storage capacity, but I don't have the equipment to find out yet.

[@ThinkingandTinkering]

wow - I think you are so lucky! what a great place to live - rock does have a good thermal capacity mate

[@newmonengineering]

This reminds me of my clothes dryer. I had the brilliant idea to use foam insulation all around it and then a put a small duct fan in a 10in duct and pumped the hot air out of my attic through the dryer. The dryer sucks in ambient air and heats it and pumps it outside normally. So when I did this to my dryer, I reduced the temperature in the attic which reduces the houses cooling cost and also it reduced the heating element required in the dryer, they use a sensor to turn on and off the element. It worked amazingly well at reducing my power. I just through I would share because it is an interesting way to save power and it really does work!!

[@ThinkingandTinkering]

@@newmonengineering that is a really awesome share - thank you for posting it mate

[@newmonengineering]

@@ThinkingandTinkering you are welcome, I am actually surprised no one has built one on the market like this for better efficiency. Of course it's limited to having an attack that you can cut a 10in hole into, but honestly I think it could be a commercially available option for drying the clothes. The attic air is quite hot already and the movement of air through the attic reduces the cooling on the house because fresh air comes in through the sofets and that is at ambient temperature which is lower than the attic air temperature

[@TedDunning]

This is a nice start. One very interesting thing that the Finnish company is doing is heating the sand electrically and then removing the heat from the outer parts of the sand first. By doing this in a controlled way, they actually can increase the efficiency quite a lot (they claim 2x) because the sand you have cooled becomes a partial insulator for the remaining sand. That approach does, however, mean that larger batteries have a large advantage over smaller ones.

[@3dmaker699]

The indigenous peoples of New-Zealand would dig a large hole and line it with stones with a stone layer at the bottom. They would light a fire to keep warm at night then as the fire went out they would put food for the tribe in the cooling pit and cover it with dirt and let the food cook for a few days.

[@BaliFoodTreePlanter]

Can you talk about dangers of temperatures above 1000F and how it destroys ozone layer?.

[@jonnym2004]

A great channel, your keeping my brain very busy. I watched this and the rocket stove water heater video and I can't help thinking a combination of the two would be helpful. Run water pipes through the sand bank and add an oil drum cap and chimney to gather the wasted heat. That would hopefully have the effect of gathering heat for hot water for along time after the fire has gone out. Rocket stove mass heaters are great but as its illegal to fit one in your house(in the UK) an efficient water heater outside might be more use to alot more people. What do you think. Would the 100c temperature cap on the water drain the sand batterys usefulness too quickly? Thanks again for the excellent channel!

[@smartcookie11]

You can add insulation, so no heat will escape

[@woodworks2123]

Seeing those big silos in finland holding loads of sand is obviously very expensive but I thought of a much cheaper way to do it, just dig a hole in your garden, say 1 mtr square and 2-3 MTs deep. Use thermal insulated blocks on the outside and fill it with sand and the exhaust of a rocket stove, up and down a couple times then out and then either pipes for water or ducting for air. Water or air goes down cool and comes up warm/hot, put an insulated lid on top and that amount of sand will hold alot of heat for a long time at not a huge price. Charge it over a few hours like a huge storage heater but the heat should last a long time, days I reckon

[@smartcookie11]

If I heat sand to 400 degrees temp, then what will the half life be, or in other words how much heat diminishes over a period of time. So will sand cool slower than water. Surely heating sand must be much harder than heating water, then why not just heat water. What advantage does sand provide, I am still confused.

[@stuffoflardohfortheloveof]

Hi Rob, that was really interesting. One question if I may……you said it took about an hour’s burn followed by 3.5hrs of useful heat……how long did it take before the stove gave off any useful heat? In other words did the sand itself soak up all the heat in the first hour?. Thanks 👍

[@guysquarred]

The metal body of the stove is continuous so it must conduct the heat from the burner and radiates heats before the sand is even hot

[@MegaScienceguru]

Ive always looked towards sodium acetate or "hot ice" because you can use it has a thermal battery that can hold the latent heat for days until you need it

[@tommieronen7424]

Again very nice video Robert! 😁 We actually have found out that this doesn't work so well if you burn something because of the losses in exhaust. When you heat with electricity you don't have that problem 😁 How about video where you heat a ton of sand with solar panels? 😁 There you have to find the right resistivity.

[@ThinkingandTinkering]

Thank you Tommi - I agree - just when you look at the numbers you can see a lot has been lost - the sand is storing well - which is what I was interested in but the percentage loss of possible thermal energy was high and like you I concluded the heat loss was through exhaust - you can actually see that in the heat haze. Cheers mate

[@alexnazarene3071]

Awesome! Thanks so much for making this video! …. So after 3.5 hours, it had cooled down completely to ambient? You didn’t mention the temp reading at the end of the video. Thanks !! Deeply appreciate you sharing your curiosity, exploration and industriousness!

[@totally_not_a_bot]

Check the bit at 5:20 Slightly over 50°

[@gerkostuff598]

Great videos! I wonder if there are good DIY sand battery heaters using (multiple) PTC heating elements to heat up a room or at least to cheaply pre heat a room?

[@victoryfirst2878]

Now their something that I never thought of for holding heat, SAND. I would bet this will hold heat for a good bit of time. Job well done Robert. Peace

[@gedhuffadine1873]

I have a wood burner with ove, I put storage heater bricks in the oven keep warm all night

[@victoryfirst2878]

@@gedhuffadine1873 Nice to hear that it works so well Ged. Are they regular clay bricks ??

[@gedhuffadine1873]

@@victoryfirst2878 no they are the ones that go in storage heaters but clay ones could work

[@victoryfirst2878]

@@gedhuffadine1873 Thank you for clarifying this question Ged.

[@Jimbo878]

Hi Robert, enjoyed this video and the subject, while contemplating making a storage device like this I wondered if granular table salt would work in this application 🤔, it's cheap and readily available, my other option would be pilfering the white bunker sand at my local golf course 👀, maybe someone would know the thermal retention of table salt?

[@ronaldwidd1516]

Thank you for this! And all the videos!!!!

[@paulsojourner7551]

I'm curious how much heat salt will hold and if it will hold it as long as the sand does or longer.

[@vinquinn]

4.6 kWh is about enough to keep one medium size room warm for one hour in the winter. The temperature starts off nice but then gets cooler with time. You need to put it in a box with flaps or something to control the release of the heat.

[@misamsung6191]

It would be interesting to see how long a coil of steel pipe would produce hot water for in the sand battery. Steel would be structurally better than copper or aluminium as it has a higher melting point. One should get a lot of hot water/low pressure steam out of the device for a long time which could be fed into a radiator of some kind for heating. I would imagine that with the hot water recirculating back into the battery would extend the cooling off time.

[@ThinkingandTinkering]

maybe - go for it mate build it and let us know how you get on

[@joelstephenson762]

I know I'm a bit late to this one but I was wondering where the video is that shows how you made this heater.

[@IvanonUrsul]

Hi Robert, nice videos about sand batteries. Any chance you can record another one showing characteristics of a sand batteries and it's capacity to store heat on a long run(days, weeks, months)?

[@12thsonofisrael]

Continue your good work. And, I agree with my son's assessment of everything you do, "There's nothing dumb about anything that you have ever posted."

[@hamood1234fool]

Robert, can you show us the most efficient way to convert heat to electricity?

[@agn855]

An atomic plant.

[@maxmax-sr9lh]

Steam

[@smartcookie11]

​@@maxmax-sr9lhwhat about thermoelectric panels. If it snows outside you can create a even greater temperature differentiation.

[@maxmax-sr9lh]

@@smartcookie11 not very efficient like 5 to 10% conversion the Best its a stirling engine can reach 40 to 50 % if its well construct

[@smartcookie11]

​@@maxmax-sr9lhisnt it impossible to reach 100 efficency for any given engine. So even I manage to make the other side really cold, I would still be unable to reach 100 percent efficiency. But turbine engine might be 80 percent efficent.

[@noahriding5780]

How long can you get heat for w the sand battery? Ideally someone is probably thinking of comparing this to how much warmth they can buy before going to sleep at night with it heating their room. I doubt it would last a full 8 hours?

[@SpencerBrennan001]

I wanna try it with a solar concentrator heating setup.

[@andrewscott985]

Hi. At the end of the video the seagulls were in fact crying, thinking that with the efficiency that you've discovered, the people are going to use all the sand on the beaches they use to relax. Cheers.

[@robertlavedas4964]

Does black sand, preform similar? Magnetite etc? For use say in a solar heated version for hot water heating?

[@user-fb9os7hy2y]

Hello Robert..is it the sand or the air trapped in between the sand that stores energy?..would compacting the sand improve efficiency?..if so,why not use rock?

[@tugasemnome]

Looking for more to see more... can from this sand battery instead of heating getting Kw?

[@martinbonner8626]

Add an air jacket around the sand mass and a Peltier fan to draw air past sand and have an efficient room heater if the wood is kept in the heater

[@BeowulfNode]

I'd love to see you hook up a sterling engine and electric generator to this thermal battery. Then see how long you can run an LED that's bright enough to light a small room.

[@nic5779]

yes or/and loads of peltiers

[@Barthoization]

So, an oil drum , 200liter of sand. Copper coil. Good amount of insulation around the drum. Heating element of a water heater at the bottom. Smart plug that dumps my extra solar power during the day into the sand. I could send water trough the copper pipe and into a radiator with fan, heating up the room long after the sun has gone down.

[@joshsk8erx1]

Since water would be better at storing energy, I'm curious what is the highest pressure you can put water under in a pressurized vessel to prevent boiling.

[@jolo-bolo]

How long do you think this would heat water for if you added a coil of copper tubing into the sand. Then pumped the water round attaching it to radiators. If you got the water moving fast enough so it will not boil of course.

[@enyha]

Scrap bricks from redundant electric storage heaters are free/very cheap resource for heat storage projects, forges etc. Often find them 'fly-tipped'! (Love these vids from R M-S)

[@AlanAlanAlanDave]

Could you also then add a removable coiled copper pipe around it with water in and out valves as before for also boiling water for such a thing as a hot tub, bath etc?

[@LaymansEpoch]

Ok if I had 2 fire extinguishers for example joined together. 1 has a heating element which is connected to a wind turbine or solar power to provide power to the element. The other is full of sand. The heat transfers to the sand. How would you then pump heat out in to my home? Is this doable? Or am I thinking BS. Thinking of an alternative to a wood burner?

[@chelsona2574]

isnt it possible to take distilled water to a higher temp in a microwave? i remember it would explode yeah?

[@speedlearner]

Here is my first question. Could you draw heat from antifreeze and store that heat inside a sand battery? I thought about using antifreeze inside small pipes on the back of a solar panel and transporting the heat from the antifreeze into a set of portable sand batteries.

[@smartcookie11]

How would ypu heat antifreeze, and it is expensive

[@LittleRapGuy]

Great video...

[@loam5735]

My thoughts for an off grid system was a large reservoir of sand or crushed rock with a solar concentrator system. Using air instead of oil to transport the heat to the reservoir would cut down on breakdown of the oil and pump issues such as clogging. Then use a sterling engine as a generator for electricity and the reservoir also as a way to heat the house at the same time. Have yet to purchase the land for it but a work in progress. Your thoughts?

[@joergsonnenberger6836]

Siemens-Gamesa has a prototype thermal storage facility (Google ETES and the company) near Hamburg based on vulcanic rock and electric heating. For extracting the heat, they pump water in and get steam out, which is fairly effective. The steam can then be used via heat exchanger or to drive a steam engine.

[@FourthWayRanch]

How do u make a big one cheap? Cement block tower with insulation wrap maybe? Cheap heat transfer fluid? Maybe water is good enough

[@speedlearner]

I also learned that through convection that was created from sound waves that you could create heat. Could you transport the heat generated by this convection and store it into portable sand batteries?

[@smartcookie11]

Never heard a of a convection. Is that a new generator model or something.

[@akashashen]

How does this compare to the molten salt heat storage used in large scale solar thermal systems?

[@speedlearner]

Could you crush broken glass and turn it into sand? If so, how much sand can you create from broken glass?

[@valdirrodriguesbarbosa7224]

Congratulations. Can you afford a schema of the internal parte?

[@fireandforge]

So how do you convert the thermal energy displaced from a sand battery into electricity?

[@ThinkingandTinkering]

in so many ways and I have already answered this question - twice

[@fireandforge]

@@ThinkingandTinkering Ok so I answered my own question in a way. Would a well insulated sand battery with a coiled pipe in the sand that has a input sucking in cold air that is then heated up inside the sand battery with a out put using said heated air to turn a turbine in a solar tower work? My question is not very well articulated but I can't think of a simpler way to frame it

[@fireandforge]

@@terrafirma9328 Thanks

[@philipvecchio3292]

I wonder what would happen if you had a copper coil in there, but ran the copper coil through the sand. The sandwich would be a heat buffer, the water is easier to move and use.

[@ThinkingandTinkering]

it's an idea mate - go for it

[@graysonsmith7031]

It seems like the most practical use for this is an oven. There isn't really any loss in efficiency over a heat pump or battery storage since the only way to heat up an oven is either gas or resistance elements because of the high temperature. Using a fresnel lens to heat up the sand rather than a solar panel and resistance element would mean you'd be capturing and storing solar energy as heat at close to 100% efficiency. Then the oven it will be warm or ready to warm your oven whenever you need it. You could also slap a TEC to the sand and another to the back of the oven, so electricity is generated as the oven cools down and generates electricity from the sand if there is ever an excess of heat. So you could in theory have an oven that gets all its energy from sunlight and would generate electricity as the oven cools down or there is an abundance of solar thermal energy. With all except the electricity generation operating at near 100% efficiency. Even the TECs could operate at their best efficiency due ro rhe high heat and the heat passing from the oven/sand through thr TEC could even be used to heat water for residential use.

[@salaciouscreations4323]

So if I filled the reflecting box for my methanol heater with sand it will keep pumping out heat long after its ran out of fuel

[@barbaraferron7994]

You heated that up super hot and then left it unattended for a few hours?

[@MichaelDobbins]

We have a lot of old concrete from our crumbling infrastructure that we could recycle into heat batteries (as one of the ways to reuse this old concrete.).

[@ThinkingandTinkering]

now that is an awesome idea mate

[@gyurterd8922]

WHAT ABOUT ROBERT IF INSTEAD OF THE ROCKET STOVE WE USE A WOOD GAS REACTOR TO PRODUCE THE HEAT WE NEED FOR THE SAND BATTERY AND AT THE SAME TIME WE WILL GET GAS FOR OUR HOMES? HOW CAN WE MAKE A PROTOTYPE OF A SAND BATTERY? CAN YOU PLEASE ELABORATE ABOUT THIS TOPIC?

[@petercordingley927]

Hi Robert I purchased the concrete mould and 300mm box section as per video and I watched this video and I thought if I add a pot holder like you made for the rocket stove and filled a large saucepan with sand would I create another version of a sand battery? If it works possibly buy something bigger

[@ThinkingandTinkering]

yeah you would mate - pretty cool idea - you should do a video and share it too!

[@petercordingley927]

@@ThinkingandTinkering Thanks I think I will when it gets delivered next week, although I'm more than happy if you want to do a video on it as you are fantastic at doing the videos

[@envisioneyewearstyles9684]

Hi Robert. Thank you for the great video. What do you think are the possible ways to store summer heat in sand and use it in winter. Do we need solar collectors with oil as the heat transfer material or are there better ways to collect heat from the building itself maybe from the inside of buildings and storing it in sand

[@burgersnchips]

Ground source heat pumps are for that. You use the heat pump to remove the summer heat and send it into the ground and then reverse it in winter. If you don't use a heat pump and just send air through pipes, you're going to store only a day or two of heat before it balances off because the temperature differential is too small.

[@absolutekarl]

Robert ... I've been thinking about this approach for a while !. I've got 1800kW of PV power every year in summer that I just can't use and would love to "store". I know one of sands attributes is it's stupidly high temperature ability, but with the only realistic way for me to recover the stored energy being via water, I'm wondering how working at (storing at) under 100 degC might negatively affect the system. I'm also having difficulty working out the quantity of sand required, given vastly different "specific heat" (and other) figures appearing on the web. Thoughts truly welcome !! Cheers !

[@grahamsmith5780]

Just watched Matt Ferrell’s video about latest applications of graphene and I started wondering if maybe adding a little graphene powder to the sand might improve heat distribution in the sand.

[@fransjebik8554]

Pr a graphene sheet between a + and - wire to heat the sand with 12 or 24 V? What do you think?

[@Alan_Hans__]

As an Aussie I reckon we should be using iron ore rather than sand. We have that stuff just laying around everywhere and it has about twice the density of crappy old desert sand. I should think that it would have a fairly high heat transfer rate as well.

[@SamStack]

I wonder if sand releases heat more slowly than iron ore would though. When I think of metal, I think it heats quickly and probably cold quickly too.

[@silverpc4611]

if you was to put a winding coil inside of that tank and then poor sand in from the top. then put water through the coil for steam and turn a steam turbine. how long would the heated sand last? and then if you could convert it to some underground tank with couple solar reflectors.

[@ThinkingandTinkering]

no idea mate - give it a go and let us know

[@danielmiller2886]

Hmmm. Does sand store "cold" as well?

[@buffplums]

0:28 😂 The casing you have max for your sand battery reminds me of Bender off futurama 😂

[@LeonPhythian69]

Could you coil some copper pipe inside the sand and heat a set of radiators through the night with this idea?

[@thesurvivalist.]

They work well, I want to build or buy one for my house!

[@fransmurati2370]

Will make a great heater if you use Terracotaclay pot or The tradisionsl Spanidh fireplace made of terracota

[@markusgarvey]

I believe the Chinese created a heating system using ceramic , with a firebox built underground, to heat houses. Still used today.

[@fransmurati2370]

@@markusgarvey Thnx very interresting, putting heated sand, and then using a hallogen lamp to first heat-up the sand, in other words using a hallogen lamp as a heating element.I took a 150watt hallogen lamp and measured the temprature, it reached 230degrees celsuis in les than 4 minutes. I think there is going to be a lot of ideas that will be taking off from this sand /battery concept.

[@ThinkingandTinkering]

yeah it would

[@chrisreeves8037]

1990 was the first time I heard of a sand-battery at a Dennis Lee presentation. He learned of the concept from Steel Mills. You can find him on You Tube.

[@jozsab1]

I still use half a ton brick stove( 40 years old stove). Keeps the room warm until morning. Sand batter sounds like reinventing the wheel with extra steps.

[@markusgarvey]

Yes, but brick does not hold heat long. You are on the right track.

[@ThinkingandTinkering]

hmmm? you have to make bricks? I think it's horses for courses mate

[@jozsab1]

@@terrafirma9328 when you build a stove, you build it to begood. you can add sand between the walls, you can size it "whatever" heat capacity, you can size the fireplace to not refuel it all the time... we are talking about a multi thousand years old technology. and it's good

[@josuelugo4506]

Hi Robert . Do you have other videos where you swap the power source of a device to the sand battery. It will be cool to see that and if there's other tech that is needed to make the sand battery connect to a device. Thank you :)

[@bk7278]

I went down the mass heater road and after a lot of trying I decided you are better off just letting the heat enter the room the mass actually insulated and caries the heat out of the system if you are looking for efficiency weather proofing is a much better use of time I do use a pellet rocket stove gravity fed and home made so I know how fun they are I have a water system that heats a radiator no electric needed the burn chamber is 2 inch treaded pipe into a small barrel and out a 4 inch exhaust steam punky simple and super efficient and clean

[@Lupinlethird]

me just visualizing, those quickconnectors plumbed with an embedded spiral for extracting hot water, and fins on the burn chamber if that would speed up the heat transfer, i read indeed about secondairy air intake for afterburning it is a pitty that gravity is comes heavy with these

[@TazerGames]

Nice, still waiting for the stirling though It could potentially be a good pair with this too

[@markusgarvey]

How would you exchange the heat?

[@ThinkingandTinkering]

why don't you just make a suggestion? It's far more helpful you clearly have an idea of how you would go about it

[@ThinkingandTinkering]

somethings take me a while to get round to - I do have rather a lot to do lol

[@TazerGames]

I know it would, but i didn't really have anything specific in mind and i enjoy alot watching what you came up with, in every vid I understand and deffinitelly don't complain, i just really like the stirling😃

[@aether-elephant]

Ur reading my mind again....

[@markusgarvey]

Isn't it funny how he does that?

[@ThinkingandTinkering]

lol - my bad!

[@paulmessier8703]

Can a sand battery use a high-temperature oil to hold more energy?

[@smartcookie11]

But wouldn't the oil evaporate

[@bobsnabby2298]

We had a brick stove which was heated with few kilos of wood during the day, it got hot and remained warm till the morning. This system has been used for thousands of years. Why the sand suddenly is a big "woah !" ?

[@romanregman1469]

Would you compare sand as thermal storage with lead transition from solid to liquid and back?

[@scantrain5007]

The Sand Battery reminds me at Off-Peak Storage Heater which became popular in the end of 60ies. Instead of Sand was to bricks pressed rust. Unfortunately I don't know how high was the temperature inside. It's been working very well. So the idea is not new - it's now a matter of construction for longe time heat storage (only...).

[@ThinkingandTinkering]

me too

[@clearwax]

What about “Heat-pipe” integration? As it’s one of the most efficient ways to distribute heat and is the standard in a small form factor uses for things like CPU’s

[@clearwax]

Perhaps a a heat sync to the chimney that gores throughout the dry sand for faster heating of the sand that a water coil can go through, and the heat pipes can protrude out the top to a radiator with a fan. Or even no chimney, just an exposed copper heat sync over say a candle or a smaller chi on a waste oil /vegetable oil burner with a wick to directly xpose the heat sync with heat to transfer that heat through the sand (to heat the sand) and a radiator with fan for heating ambient air for any excess heat in that heat pipe… while also promoting the capillary action to condensate the liquid inside the heat pipe. (I’d suggest filling copper tubing with the ultra tiny wires from a car stereo that’s been unsheathed and insisted to promote the transfer of heat and condensation to its most efficient. Than with a minute amount of water added to the heat pipe, it’s capped off with a soldered top (which heats the pipe expands the liquid to vapor, then the seal would cause a vacuum for lower boiling point efficiency. I’ve seen a heat pipe made similar to this on another channel, but the vacuum is important. And it would ideally be used with small amounts of fuel (like I mentioned, a candle, or wicked ignitable fluid, NOT a fire with old and other hotter heat sources. This is an attempt to make as efficient as possible heaters for either room heating or the inclusion of a copper coils to also heat water. I would love to see this attempted, if I’ve explained it clear enough.😅

[@Nuts-Bolts]

Molten zinc (or lead act) will keep giving off a 'steady' heat as it solidifies. Next stage is a ceramic blanket to hold the heat 'charge' for longer.

[@pa_maj.MARTINI-van-MAN]

Over 200 C and zinc gives of toxic fumes, led fumes are also very toxic. Depending where those fumes are vented to, it could be lethal. I think sand is a cleaner option N&B.

[@ThinkingandTinkering]

for sure but they sound expensive

[@Nuts-Bolts]

@@pa_maj.MARTINI-van-MAN Such systems don't need to be vented!

[@pa_maj.MARTINI-van-MAN]

@@Nuts-Bolts Oh' that's better. No venting is something I didn't think off. Does any pressure/expansion happen at all NB?

[@Nuts-Bolts]

@@pa_maj.MARTINI-van-MAN Molten metals still expand with. temperate (so expantion space required) but no pressure problems below boiling point. However, there are some considerations. For example, there are uncertainties regarding corrosion and liquid-metal embrittlement of containment vessels with lead at very high temprature. A potential problem for lead cooled nuclear reactors. Don’t think Rob though, is going to build one of those anytime soon… I hope.