Sand Batteries Effective? Testing Results Revealed for free heat!

hey everybody welcome back and thanks for joining I want to recap on Sand battery project I have completed sand battery version 2 and I've got some data and it's not very good so let's recap what have I've done and what I was hoping for my intention was to create a sand battery that I could use to heat air inside of the tent or a small room in the event of a power outage or cold weather situation I'm in Austin Texas and right now on February 1st we are covered in ice and a lot of people have lost power I have not yet thankfully but um friends of mine have and lots of other people have so I was trying to create a way that I could essentially replace a Mr Buddy propane heater you know get a couple thousand BTU out of it uh out of basically a bucket of sand radiating heat or radiating hot air where I could keep some warmth going I could theoretically charge it during the day while I've got sunlight which we don't have right now but charge it during the day via sunlight converting that sun the solar energy into electricity into heat heat up a bucket of sand to a couple hundred degrees maintain that heat and have that heat radiate out slowly over a span of hours hopefully making it through the course of the night well heating up a bucket of sand to 500 degrees is only one piece of the equation there are other videos on YouTube a very proud video creators um using their laser pointer to show their bucket of sand that's several hundred degrees and oh wow look what I did okay that is very neat now how do we translate that into usable heat how do you turn that into something that's actually going to like keep me warm now I know the way that thermodynamics work to a small extent that heat is heat is heat is heat meaning that you're going to get the same amount of heat output of BTUs or whatever thermos from a bucket of sand at 500 degrees versus a fan blowing over that heat and transferring that hot air to a vent pipe or something like that like there's no such thing as gaining heat that already exists but you know what I found thought about that you know having a big bucket of sand is really not the the best way to sort of utilize it so I was hoping to try to move that air into a smaller space and also trying to find a way to measure it that's the big drawback that I've seen on all these YouTube videos is people are not measuring their results in a good scientific way so the way to measure the results is to take temperature readings before during and after you know you deploy your heater so in a perfect world I would take my bucket of sand heat up to 500 Degrees put it inside of my tent inside my house and duplicate those the that scenario and measure it when I put the bug of sand in how hot the air inside that volume of space gets and then how long that lasts okay and I was willing to do that but I figured let's start this on a smaller scale and just kind of see how it goes so that's exactly what I've done or what I did do and I was not impressed so I'm going to show you the video of my construction but here is the abbreviated version bucket of sand 50 pounds of sand with two electric uh stove elements in it putting a couple hundred Watts off the check my measurements the sand heated up to three or four hundred degrees inside the sand I have little slats of aluminum bar sticking out of it to help radiate the heat upwards right those aluminum elements got up to about 160 degrees thereabouts and then I have a lid on the top with a very low powered fan to push air over that hot sand and and over that hot aluminum and cycle it up to a very small cardboard box and then the air comes out of cardboard box goes into the other side of the bucket and we have sort of this Loop so I'm constantly warming that same air up and up and up it worked on paper so the air went from 70 degrees to 80 degrees wow okay and then I unplugged it and it took about five hours for that heat from the air space of that box to go from 70 degrees to 80 degrees it took two and a half to three hours for the aluminum bars to come up to temperature so uh it took about five hours for the I unplugged the right five hours because five hours of the amount of sunlight you have on a solar system it's about five hours to go from seven degrees to 80 degrees and as soon as I unplugged it that temperature immediately started to drop and fell off and by about five or six hours later I had gone right back down to 70 degrees obviously there's a lot of variables in here for those who will ask this was all set up in my garage my garage was about 65 degrees constantly so there was no external temperature you know interacting on this yes I understand that the bucket even though it's got a concrete liner is not as well insulated as it could have been absolutely is that cardboard box airtight no did I take the edges to try to make it airtight yes I did um so I think that this was a pretty reasonable small scale test and it just didn't work out particularly well um I've done a lot of reading lately like trying to figure out the math behind watts and BTUs and how many BTUs per square foot and the math numbers really do not make this line up so I'm gonna come to the conclusion that in my opinion small scale sand batteries are not feasible for sort of residential use at larger scales and Industrial scales they're obviously being used in different parts of the world like you have to get into much higher temperatures with much more efficient heat transfers than what I think you can kind of do at home now one of the questions that came up comments came on in San Battier real number one is what about water so I was really really thinking about making a version three using a big bucket of water instead of sand since it was pointed out to me repeatedly that the heat capacity of water is like five times greater than sand even though you can heat sand up hotter than water water has better heat capacity than sand does so I looked into it I really tried to crunch some numbers the problem seems to be the the jewel rating the heat capacity you have to put a lot of energy in to water to heat it up a quick search on Brew making forums funny enough one of the questions is what how big of a heater do I need to bring my 15 gallon batch of beer up to Boiling and they're talking about 4 000 Watts four or five or six thousand watts of immersible heaters to bring 15 gallons of water up to boil that's an amazing amount of power now yes you could put this on a bonfire and heat it up using fossil fuels but I was trying to do this in a renewable way so it requires an enormous amount of power to bring that water up to temperature it may hold that temperature longer but you're going to put a ton of energy into it to get it up to that rating and I'd really it'd be really interesting to see if that's worth it versus just plugging in a little space heater that draws about a thousand watts and getting more BTU energy out of that so I think that solar that sand batteries and geothermal and that same batteries really do make sense if you have an external heating Source like geothermal it's a good storage capacity for that but you know the thermodynamics of this are really not working you know the amount of power you have to put in versus the heat capacity you get out um the math is just not working and I think my small scale test has kind of shown that to an extent so this was a lot of fun um I love building stuff obviously there was a lot of Engineering in here that I got to kind of play around with and I'm going to show some video and I'm going to show some build video but uh I think I'm done with sand batteries and I think I'm going to move on to my next project so uh I hope everyone has enjoyed this and uh drop a comment and give me your thoughts and enjoy watching my test videos thanks so my Crucible is good and rock solid today and it's time to work on the lid this is obviously a big piece of plywood and that is the diameter of the outer trash can and these are brackets to attach a 120 millimeter k-span two four inch dryer vent so I'm going to cut this out and cut out these holes in the center and work on my lid foreign so here's the first module first heating element no worse for wear so I'm going to clip my silicon wires leave me a long tail and connect them to the second one here is my heating elements nope let's drop them back in foreign okay exactly as I had calculated I've got 55 volts at 4 amps into the heating elements for 225 Watts so this is right in line what I expected um my step-up converter got knocked so I'm gonna see if I can adjust the voltage to get up to 60 65 but all the loads are all the loads are right within where I calculated them to be so or a good shape so this obviously is a cardboard box what I'm going to do is assemble this box it's about 18 inches Square I'll measure it just a second and I'm going to use this to simulate my tent obviously I know it's smaller than a tent but it's the biggest confined air space that I've got so I can measure these are 120 millimeter case fan to four inch dryer vent adapters so I'm going to put two of these on the side one is an air intake and one as an air output so I'm going to circulate the air through the lid into this box what I'm going to do is I'm going to put my Data Logger inside the air cavity and watch as it's how much the temperature climbs throughout the day and I'm going to let it run for five hours to simulate five hours of sunlight and then I'm going to unplug it and see how long that air continues to circulate and at what temperature cutting a round hole in cardboard is harder than it looks foreign just in case you missed it I have these bars of aluminum inside here that I am expecting will hold the Heat and help radiate the Heat and I've set them on either with the heating elements on either side so they're pushing in this direction and here's the lid so I'm going to orient the lid lid on either side of where the aluminum bars are and the theory is that the hot air will circulate sort of around that way give it giving it the maximum amount of time so this is a very low output fan I just want to help it just kind of just push a little bit okay foreign battery 2.0 so I've got my concrete Crucible down below with 50 pounds of sand in it with two electric heating elements on either side filled with sand with bars of aluminum inside with a very small 120 millimeter fan and gets 35 cubic feet per minute in theory I'm going to heat up that sand heat up that aluminum push that that hot air by convention by convection and also buy a little nudge from the fan we'll go up into the box and then circulate back down and we'll get this circular system going in theory so it is high noon I'm going to plug this thing in and let it rip till five o'clock and then unplug it and see how long the heat uh continues I'm going to get my Data Logger here is my elitec temperature Data Logger that I use for my preliminary testing so I'm going to shove this probe down the top of the box and keep an eye all the on it for the next couple hours see what happens oh Brad it's been five hours and we have some data it's not very good but it's data so the element the metal strips inside there this is clamped to them are at 156 degrees it's been right at five hours my little fans still going so I'm circulating air and inside the box is 82 degrees so we went from 73 to 82 so not quite 10 degrees of Delta gain in five hours so I was hoping for a lot more but you know we got what we got so now I'm going to unplug it and let it keep running and see how long this can be maintained

Channel: Texas Prepper Projects

Views: 34,856

Keywords: Are Sand Batteries Effective, Testing Results Revealed, Texas Prepper Projects, Sand Battery Testing, DIY Energy Solutions, Sustainable Heating Projects, Solar Power Experiments, Eco-Friendly Heating, Renewable Energy DIY, Home Energy Tests, Green Living Solutions, Solar Battery Myths, Energy Efficiency Testing, Off-Grid Heating Solutions, Sustainable Living Projects, DIY Solar Power, Green Energy Experiments, Home Heating Alternatives, Eco-Friendly DIY Projects, TPP&x%

Id: Y0QFzQ-Znwk

Length: 17min 14sec (1034 seconds)

Published: Thu Feb 02 2023