Solar Sand Battery Evacuated Tube Implosion Solar Water Heater Thermal Storage

[@АнтонБахчеванов]

I'm very glad that you made this video, I'm from Bulgaria, here we have five months of winter and the temperatures are up to -15°, sometimes it reaches -20. I have four collectors that have a built-in boiler. Now I'm going to try one of these with the quartz sand to fill them up and see what the difference is in the winter.❤

[@rxonmymind8362]

Update please. Appreciate it.

[@peterectasy2957]

could that vacuum solar tube work properly and produce hot water even if you have outside temperature minus 15 degree celsius ?

[@HubbHubbs]

Thanks for this, I've just built a solar kettle from a used evacuated tube, copper microbore pipe and kiln dried sand. Boils water instantly! Never would have thought of using sand.

[@erichawkins3915]

As a co designer of the Apricus brand since 2003, and importing and testing China tubes in Cyprus in 1997, the reason explode or implode is becouse they are sold to be installed with a presurized system, which i have never done since i started in solar thermal in 1990, but i started with the developing of the hot water tank first, now called a Thermal Store also developed by my then partner in the USA Norm. My UK tube failures in the early days was found to be caused through the build up of heat in the tubes, so when we stoped useing the typical pluged tubes to open tubes with our heat pipes inside, we solved the first problem. Our latest heat pipe tube collectors now come with a sensor built into the condensor of the heat pipe, which stops tank over heating to 80c, but unless the solar industry starts to reconise that all the solar failures and the limited use of solar thermal is becouse nobody understands thermal stores, first developed in the UK by me in 1990

[@peternorman2563]

Very nice video and this explains all you need to understand about evacuated Navitron tubes. Many thanks from the UK. Dry fine sand is available here from our builder's merchants, mainly used for block paving infill.

[@triumphmanful]

wow, Dan Thanks for this! I am looking to set up those evacuated tubes to heat my home with. Up here in the NE Home Heating Oil is expensive every winter ! So any way to get "almost free" heat is a big plus for us retired folks. i think the beach sand is the way to go. AND your vids are great ! Keep them coming !

[@wingerrrrrrrrr]

Great video 👍 first one I've seen that actually gives information on how these actually operate. I've inherited components of a solar thermal system but apparently missing the copper heat pipe tubes that go inside the evacuated glass tubes. I couldn't figure out how it was supposed to work, with one end of the glass closed.

[@WinstonFord]

Awesome vid! As usual :) I think the water issue could be solved with a proper manifold seal, but I still like the idea of innovating on the aluminum fins and the wasted volume. Instead of sand, why not try a phase change material, maybe an oil or wax. With your parabolic you might need to find a pcm with flash point above 600F, but w/o a parabolic you could find a more common pcm. A pcm will also leverage the amazing insulating properties of the tubes which are typically wasted at night. Because the pcm's hold many times more heat than air, water, or sand, it could deliver heat into the night hours.

[@roidroid]

I'd been pondering a combination Solar/PCM hot water system, but hadn't considered storing the PCM inside the black inner absorber tube. It's a really good idea. Initially it seems dumb coz it's probably the most expensive/space-constrained place you could choose to store your PCM material. HOWEVER, any other place you'd store the PCM will need to be surrounded with thermal insulation anyway, so this way you're getting a double-use outof the evacuated tubes' thermal insulation properties. So really it's a brilliant idea!

[@tomkeegan3782]

Thanks Ian,very informative, I live in Ireland, I don't think my solar tubes will ever explode!

[@V2RocketScientist]

The problem with using sand as a heat transfer medium is it's going to act as an insulator and the heat will not transfer to the copper heat pipe very quickly and therefore, there will overall be loss of thermal efficiency. You're able to recoup some of that heat at night and that's the problem; the heat stayed in the tube for a long time rather than getting transferred to the water storage tank and therefore a large portion of the heat was lost back to the ambient. A vacuum tube is an excellent way to prevent conduction and convection of heat but radiation still occurs. The problem shown regarding the water hitting a hot tube and causing an explosion should not be a problem with a properly designed tube collector. The top of the tube is inserted into a manifold which uses a gasket to prevent any water from the elements getting in. Rain or not, the tube will be safe.

[@MyAItolife]

Hey Dan, Its convenient for survival such as sterilizing hot water or soups as its already a container. I like that its set and forget for cooking. I boiled an egg to see if it was a good survival cooking tool. I made a video if you want to see it.

[@SimpleEarthSelfReliance]

Thanks Dan, this is a really cool video that answered more questions than I had when I came here. QUite a fan of this science, and thinking about my next DIY water heater. Your video is pleasant and informational.

[@AnotherSimpleton]

Great idea using sand instead of the metal fins to keep the heat in longer after the sun sets. Just curious, did you measure the total weight differences of a tube with the fins versus a tube filled with sand?

[@GREENPOWERSCIENCE]

The sand adds about 5-6 pounds for the large tubes and 1-2 pounds for the smaller tubes. The only difference is handling. When filled with sand, the weight stress on the continuously formed glass connection is greater so do not set them down hard or with force. Other than that, they work the same in terms of structure. The sand has been a very good alternative. I have one large tube in the shade and the condenser (tip) reaches 135 ˚F with no direct sun exposure after only 2-3 hours on a sunny day vs. close to 300˚ F in direct sunlight. Thank you for the nice comment and question.

[@Iaapwm]

Good one Dan, many thanks from Lismore NSW Australia.

[@erichawkins3915]

They implode becouse the tubes are closed with a plug and then when installed, the solar side is closed loop, creating tempertures in the loop to over 200c. But you are 100% right to say they are the best, as had on my UK roof for 12 yrs, but use all the day time heated solar water into my 250 litre thermal store to heat my 12 radiators during winter months.

[@ernestoalvarez3707]

Those are the water heaters used in Mexico, and it is awesome since you pretty much do not have to use electricity or gas to heat the water up anymore, they are pretty efficient.

[@rongray4118]

Dan - this is fantastic!! We are in Northern Nevada and I wonder how much more efficient this would be!

[@HillOrStream]

Great to see new videos from my favorite diy energy channel.

[@GREENPOWERSCIENCE]

:-) Thank You!

[@carnini]

so glad your making videos again

[@iindii]

Sill going strong mate. Use some parabolic dishes to heat up a massive heat sync.

[@sylvanenergy]

good safety info Dan, Thnx for sharing your insight.

[@Sailorman6996]

Just wanted to add on the sand in evac tube, what you win in the evening as delayed heat- you loose in the morning as heat is delayed. Most likely you loose more than you win as the accumulated heat cool off slowly - there is lots of energy lost in the dense sand as it falls under useful the temperature. Every morning you will start with cold sand. Cool feature with sand but not adding energy.

[@anchalgan]

This is the very good information about green energy

[@keeperofthegood]

Two options that come to mind for me would be either perlite or ceramic sponge. In either case, is there no boot or deflector to prevent water ingress?

[@MrCountrycuz]

God bless Dan and his mobile home.

[@dashankpatel2503]

Which sand you have used over there and where I can find that ..... I am from India doing some research work on tubes so I need your help ... Please help me out .... Will be waiting for your reply

[@superjeffstanton]

"Beach sand" its from the beach. Any sand will work about the same.Use Sand

[@dashankpatel2503]

Jeff Stanton hey in which month you have done this experiment and your location. I need this just because I can find solar radiation of that mouth. So please help.

[@nicclark9791]

How can you shut your system down without removing the tubes, lets say I don't want it working in the summer, can I just drain the system down and leave the tubes where they are or will it get too hot in the manifold????????

[@raysmith8665]

Thank you Mr. Dan. Thought on useless other wise desert sand?

[@electrodacus]

You do not increase the efficiency using one of those vacuum tubes with a concentrator on them. Efficiency will be probably almost the same what you do is just increase the collecting area. Having sand as thermal mass inside the tube has no benefit. Sand by volume has just half the heat capacity of water so is of no use to have sand inside the tube. Sand is also a fairly bad thermal conductor so the aluminium fins are the optimal solution. Solar PV panels will take about 2.5x more area for the same amount of power but they will cost about the same as solar evacuated tubes at this point in time. So I will fully heat my house with electricity from PV panels since it will be the least expensive form of energy and the energy for the heating part will be stored in thermal mass in my case a large 14cubic meter concrete slab that can store about 100kWh of energy while keeping the floor temperature at more than acceptable temperature. There are huge advantages to PV panels for heating like no pipes with hot fluids and pumps and there is no problem if you have excess unused energy no need to divert that as with solar tubes so that you do not damage the installation or cover the tubes. The down side is that it takes 2.5x more space as I mentioned before.

[@burnerjack01]

Goes to show that if it were optimum, the manufacturer would have designed and shipped it that way.

[@johng.3740]

That is correct efficiency is NOT increased by using a concentrator BUT, what is increased is the ability of that vacuum tube to collect sunlight, hence energy.

[@yoppindia]

Sand will not increase pressure inside the tube!

[@Helloverlord]

How can PV panels take 2.5x more space as they are 10x less efficient? From a 10sqft you can harvest 1kWh of heat or 100W of energy on average sunny day and with average gear. I agree there's top of the range PV panels that can do 3X as average thermal ( annually!) but you have to ask NASA to sell you some.

[@maksimbober8443]

Less effective three times four. No, not ten times. Solar panels have an efficiency of 17%

[@swedensy]

Nice. Damn i wish he showed how heat transfer is done those top pins to the main water line.

[@adamskinner5868]

excellent vid, good info and explanation, cheers, great help in finding out how these tubes work.

[@downtoearth1950]

We have a 22 tube evacuated solar hot water system in Australia, it provides us with extremely hot water for 10.5 months of the year with the Electric booster element turned off.......315 litre storage tank A few weeks of boost is acceptable... :)

[@ancapftw9113]

Heat pipes are supposed to hold a vacuum, which causes the coolant to vacuum boil when heated, transferring heat extremely quickly.

[@watchguy79]

Dude make a company with sand tubes !! Nice work amazing

[@robertl.fallin7062]

Love your video. Teachin the masses whats good to know!

[@TKHONDA7]

I think you need to consider the heat transfer rate of the sand. Seems to me it would be slow at getting the heat through to the copper pipe.

[@ruforufo2185]

one of these tubes might be able to run a sterling engine without the need to constantly re-focus a concentrator on the displacer piston, which has always been the bane of a solar run sterling engine.

[@tafadzwanhavira8936]

Educate Mr leader, when installing these, do you fill them up with water first then connect then to the manifold or no water goes inside the tubes.

[@Cloxxki]

Imagine a train totally lined with these tubes. On a sunny day, could it feed a special steam loc enough to really go? And into the night, from the thermal mass? Trains tend to be fully exposed to the sun, most of the time. At least here they are. Few tunnels, rarely a building to cast a shadow. Trees do happen, to a degree.

[@ThriftStoreHacker]

I was thinking about the same thing. I may need to build a small steam engine to power a generator. I was also thinking off grid water heater, room heater. with a radiator placed somewhere in the shade to strip off excess heat if necessary. I must order some of these tubes.

[@MB031]

Great idea !! Does the sand increase the volume due to heat expansion of material? If so ,then for long term use,it will crack the tube open and imagine that mess on the roof.If no expansion problems..I wonder how many tubes will hold steady steam to turn steam generator and produce some decent power.

[@roidroid]

Considering that the sand is still within only 10F of the aluminium fins, it has no advantage there. So the main advantage to the sand is that it acts as a layer to soak up (& flash-boil away) any ingress water before it can get in contact with the hot black glass, yes?

[@Duncan_1971]

Probably the most efficient way to extract energy from sunlight is to focus it into a black body enclosure such as an empty sphere with a small opening & with matt black walls on the inside. This will retain a large proportion of the energy within the sphere. Run water through a pipe & focus the sun onto the pipe in the middle of the sphere. Boil. Steam. Tesla turbine. Generator. Sun tracking Fresnel Lens heliostat.

[@GEAUXFRUGAL]

Dan I was thinking why not building a solar cooker that uses tubes? If the temp gets high enough can't the steam be used to generate electric?

[@DANTHETUBEMAN]

this is how we are going to change things for the better,, boots on the ground,, people working with things.

[@MoondyneJoe]

Hi Dan I never realised just how dangerous those little buggers are I live in a small wheatbelt / rural town in Western Australia where in summer it often gets to and over +45c i could imagine how hot they potentially get. One of my mates has a commercially brought Solar HWS in summer he either whitewashes the panels or covers 3/4 of them with cardboard or shade cloth to stop the system from constantly boiling

[@GREENPOWERSCIENCE]

They are really good and one of the few solar devices that produce useful results on cloudy days. The one filled with sand stays hot to the touch all night.

[@MoondyneJoe]

I Dont think they are such a Big Item on the Market here in western Australia as our winters dont get anywhere as cold as yours The average Winters day ( Right now ) is around 14C to 16c Around 60f ish) during the day I have seen it down to -9c at 3am at night though and we dont get snow here

[@burnerjack01]

(Just to jump in uninvited(sorry)) I have often described solar hot water as an engine without a throttle. For the very reason you mention. Its a shame to diminish the capability that way. I consider it the simplest,most cost effective way around the 'throttle' problem. I have also been taught to angle the collectors for optimum WINTER effectiveness as summer will take care of itself. I've always thought a Stirling engine/inverter system to utilize what is 'overproduced'. A company (I have invested in) is out there that makes a waste heat engine/generator set called 'cyclone Power' that may end up being the perfect match for this type of situation. I don't thnk they're quite ready for the mass market yet, but you (and others here) may find them of interest.

[@MoondyneJoe]

great Idea John, traditional coal fired and Nuclear power stations use steam, as well as focused solar farms via turbines so i don't see why a stirling engine one issue around hear is a lot of properties rely on 20,000 gallon water tanks for their only source of water For their families and we live in a dry region , So water supplies need to be managed carefully In other words you don't want steam evaporating out the Release valve But upon saying that maybe Via a Stirling engine you could capture the heat and feed any cooler water not used back into the HWS or water tank

[@burnerjack01]

You should investigate the Rankine cycle.A fully closed loop steam system . Steam 'exhaust' is condensed and recycled endlessly. Steam does not necessarily need be open loop. In fact, closed loop results in much less mineral deposits and consequently, reduced maintenance. What had been a problem with steam in the past is the fact that steam is a natural degreaser. Modern synthetics can now be employed which do not rely on grease for lubrication. Just things to consider.

[@henrydonado5495]

Awesome video clip!! I always learn something new from you guys

[@idahodad1]

I wonder if ground soapstone or a soapstone cylinder that fits inside the evacuated tube would be more efficient than beach sand?

[@LeonardGreenpaw]

I recommend a petrol oil or maybe some sort of very high smoking point oil as a medium, maybe in tandum with the beach sand? Just need to make sure its not easily flamable, maybe a simple cap would be enough to keep oxygen out

[@AisforAwesome]

I'm curious if the solar evacuated tube actually radiates heat. If I filled several with sand, and heated them through the day, could they radiate enough heat to say.....keep a small space warm?

[@bobsmith6141]

tubes themself do not radiate heat ... the inside will be very hot while the outside will be cool to the touch

[@vladimirkubicek9963]

Nice video. I have a question. My collector has 20 of these head pipe tubes. After 7 years of operation, I found that some tubes on the surface are colder and others are warmer (you can keep your hand on them). The glass tube is mirror-shiny (which should signal the presence of a vacuum - the tube is OK). Don't have experience with why some tubes are warmer and others are colder? It cannot signal a fault (media leakage) inside the unseen tube. Does it not transfer heat to the collector and therefore the heat is transferred to the glass tube?

[@TheCritterWindow]

miss your videos wish you would do more videos again

[@xxnotmuchxx]

he stopped?

[@kevinwoolass5946]

I live in the UK they work well would recommend to do but your plumbing needs to be able to take this type of system.

[@101AOK]

Sometimes I write a comment and then proof read....Glad I do! God bless,

[@rss608]

I have the style with no heat pipe and a copper coil inside the tank. I had to put a hot water recirc pump to keep it from boiling in the summer. The pump allows the hot water to be stored in my 40gal electric water heater tank. I'm on my 2nd unit. In the summer it provides all the hot water for us, in winter it acts as a preheater and allows me to run my electric twice a day for 2 hours to save on electric cost. I use no reflectors.

[@williamjsheehan]

Very useful! Had no idea, thank you!

[@DPro]

Just got seven 30 tube collectors. Interested to know of any information on the type of fittings etc to use.. Was told that compression is better due to the heat buildup my melt solder if the pumps fails.....also any links to heat dissipation ideas for the summer months cheers Clive

[@p66237]

Hola excelente demostración Me gustaría saber si eso es arena de playa la que tú utiliza en el tubo Y después le echa agua eso es arena de playa

[@mike-ology22]

English engineers invented the vacuum tube and what we use in England is an indirect system. The bellow at the top would Sandwich between a copper layer so that the water doesn't touch the too of the glass. On the copper rail gets hot. I'll see if I can make a video too ;)

[@jimmartin243]

Hay could you not use gallium in place of water and pump that hot liquid metal through copper coil heat exchangers to both heat water and operate thermal electrity generation?

[@rxonmymind8362]

How about using black sand? Any better or over kill?

[@BSAElectronics702]

good video, thanks for the info! I read about these tubes years ago after seeing them at a vendor at a show, great idea to harness the suns heat. SO who makes good tubes? I'm looking to heat my swimming pool and I know these work far better into the cool season than the plastic tube mats people use to heat their pools.

[@learningddyu]

I wonder if they consider cavitation it's a big concern with hydraulic systems

[@mspacone]

Nice work, didn't know something like this existed!

[@javodone]

No-nonsense guy. Interesting info.

[@tuscan440r]

Really interesting, thanks for uploading. Can you answer though, can a tube shatter by just overheating and not thermal shock?

[@creatingenergyeffici]

extremely useful video.. thanks for sharing this..

[@lloydmcgriff98]

Great Video,,, Thank You and Yours for All the Fat Blessings !!! =) You are Brilliant and Awesome !!! Thanks again Friend =)

[@jamest.5001]

What do these cost? Any chance of buying used? I could use about 6-12 maybe more. Can they make steam? Well I guess not useful anyway. Because of the pressure.

[@kozaczi]

I was wondering how big temperature inside it can handle, becaouse i consider to make it working only on air. Two posibility exchange air inside (use only glass tube) or solder extra coper radiator and use with heat pipe. The reason for that is to use it as direct air house heating (as suport for main heater) What You think about that?

[@peterectasy2957]

how to avoid temperature gradiend when hot water is continuosly used from solar storage tank ?

[@glendaroxas1086]

this is awesome video, great information and instruction.. thanks..

[@josephdupont]

Vaseline is it a good heat storage medium.. to pump when it is hot.

[@pacinpm2]

What about carbon in the form of graphite? It's black and I think it's good thermal conductor.

[@TheRatDog666]

Sand is a lot cheaper.

[@Jkirk3279]

Evan Zwack If you can find the perfect sand. I can go down to the local Rural King and buy Graphite by the gallon. Apparently Farmers stir it in with their seeds to make sure they flow easily when planting.

[@wingerrrrrrrrr]

Don't think it's directly exposed to the sunlight inside the tube, so it doesn't seem like the color would matter.

[@eddysparks9093]

How about copper sand, or copper dust like to use in heat pipes for PC cooling.

[@jamest.5001]

I'm also looking for a way to run a steam powered generator with solar steam. I thought about using a fire extinguisher tank with mirrored sat dishes. And build a sun tracker. To run a converted steam engine. To spin a 150 amp alternator . or two to charge batteries for my offgrid home. Since my water can't power a hydro electric generator. No head and little flow! So I'm thinking solar steam along with my solar panels. Then I can use a wood fire to heat a boiler when there is no sun. I want to burn trash and wood for heat also. Use the exaust from the steam engine to heat the house. And heat water. Bypassing the tankless gas water heater . lots of projects! If it all works it will be nearly free heat and power. With a smallish carbon footprint. Do you know of a source of quality cheap tubes. For hot water and heat anyway! Keep up the good work...

[@GREENPOWERSCIENCE]

Hi James, It will work and there are some steam videos on our channel from years past. I moved away from steam because of the low cost of PV panels now vs sun tracking and moving parts like a steam engine. The best option would be to have new water entering through several hundred feet of spiraled black hose at a very low volume.The evacuated tube can be punched in 18" versions off of the internet. The only realizing option for long tubes is a complete water heater system with tubes because the tubes alone do not ship well. I once sold them on our website greenpowerscience.com and they broke in shipping 90% of the time regardless of packaging. The smaller tubes are no problem with this. Back to the set up. The black hose water preheated from the hose would enter a copper loop, there are 5-6 tube small systems with fins on ebay so the pressure is in the copper tubing and not the tubes.You can alter this with sand etch like this video. The water has now been stepped by hoe and tubes, the final step would be a small 12 ounce boiler with a pressure release valve that either a Fresnel Lens or 35" parabolic mirror (see our website) with a sun teacher to the smaller black colored boiler. The water would enter gradually at about 3-5 ounces per minute. This maximizes the process and prevents wasted energy on large masses of water. Check our channel search for seawater and you can see the difficulty with large volumes of water. The goal is to expose the minimum amount of water and convert to steam. If you need more steam then boiler 1 would be totally full and a second mirror or lens would heat. Also check our channel for DYY Trough Collectors as they linear beam is easy and a massive amount of sunlight can be focused to one steel pipe. The pressure pre lease valve is always a must even for small boilers and the Parabolic Mirror, Fresnel Lens, or Parabolic Trough should have the beam covering about 70% of the boiler vs a small very hot spot. The small spot may be hotter but is inefficient at transferring concentrated sunlight to the target so 70% works best. Total coverage results in missed ares that radiate vs absorb or transfer to the water. You can do a closed loop system with a small pump designed for handling hot water that has pressure of 40-50 psi running from a small solar panel then condensing the water or just use a hose attached to domestic or well water. The car alternators do not work well but AC motor converters to a bridge rectifier result in higher voltage at lower RPM as car alternators require several thousand RPM to excite and cog with a load. Check our channel for DIY alternator. If you opt for the ebay mini vacuum tube heater with the prefabbed copper tube, place a flat glass mirror behind the unit about two - three feet away to reflect light from the backside. Placing the mirror directly against the tubes basically does nothing. Please let me know if you have any questions and check our channel for videos and or website.

[@jamest.5001]

GREENPOWERSCIENCE Thanks for replying . I really want to do my part to help the earth. We have been treating it rough for too long. It is going to come to the point where this is the only source that is affordable. I just hop it isn't too late to make a difference. Yes I could be on grid. I'm 30 minutes walking distance from town. But I am lucky enough to have a place surrounded by woods. Very close to town. It's not a big town but its what we got! I have thought about digging a pond and use it as a resivor for a hydroelectric project. But the water stops during a few months with no rain. I may give it a go anyway. 10-20amps at about 30v for 12-16 hrs a day is better than only using power that time. That would be enough to run my home during the normal daytime. allow my pv to charge the batteries. It's been a while since I seen your videos. I subbed a year or two ago. I haven't seen a video since well a long time. Do you have any energy saving or producing at home? Keep on keeping on man thanks again!

[@hmax1591]

great video and good information. Thanks.

[@viktorasliutkus5336]

Hello, want to ask, if solar glass tube for water heating is hot from outside, does it mean it is no good any more?

[@webmastersof]

Hey Dan why couldn't one just use the copper pipe to run directly into each evac tube and connect at the top? Would it not be more efficient to have the heat from inside the solar tube transfer direct into a copper pipe filled with water instead of heating just air inside of the tube that in turn heats only a small portion of the top of the copper pipe?

[@dabid5]

Thank you, have you got a simple reflective design to improve efficiency?

[@zacharydunn4561]

I think it would be cool if you did something on an electro magnetic harvester. I saw a video where someone had made one and it harvested like radio waves and was able to power a strip of christmas lights without a battery.

[@ennoschneyer2864]

So eine Anlage habe ich schon seit vielen Jahren !

[@Mike2infinity]

Dan, the tube that was filled with sand and then it's temp was taken 3 hours after the sun went down, for how long was that tube out in the sunlight?

[@roidroid]

3 hours, i imagine

[@purduephotog]

I realize this has been several years.. But have you considered mixing some carbon black in with the sand?

[@omselection438]

Amazing and really well explained.

[@fedeperis]

HI man! great explanation!, do you know were I can buy the tubes ? you diy the collector?

[@paulmeynell8866]

Excellent video

[@jimmartin243]

These tubes use the 126.22 hertz frequency of the sun to generate heat?

[@roberttomsiii3728]

have your tried salt as an alternative to sand?

[@tenij000]

inside of the tube the black stuff how did get that

[@chuckharrissr6846]

Can this be used to head a greenhouse in the winter?

[@hobokengar]

How do I find out how to hook up that solar evacuated tube to a battery, convert it to ac so I can plug in the household utilities ? That'd be a long answer, so a book name or website'd do. Thanx. :-)

[@MsSomeonenew]

They only heat up, they produce no electricity.

[@deaconblooze1]

These are similar to an idea I had within a system for desalinization + energy generation, wherein seawater is pumped through a similar tube that is in a parabolic solar collection trough. The steam is then used to generate electricity, which would power the pumps and such, then the freshwater is condensed. This would result in 3 salable products; sea-salt, fresh water, and electricity. I'm sure I will never get around to pursuing this idea, so I'll just give it to the internet. :)

[@kozaczi]

You just change an thermal inertia. Disadventage is so that when the sun showsup You must wait longer until the sand will heatup also, but idea is nice.

[@sundaysunday8158]

it is not, because you can have 10 tubes and got 5 of them with sand and the other 5 without sand, so you will have all day long...

[@Limou551]

does the heat of sand breaks the glass after a while?dont know what kind of glass they are using...

[@86fn]

Great Information! Thanks.

[@simpleman2919]

Awesome info lookin forward 2 learnin more info

[@nonyabusiness9747]

Dan what happened to green power science!? Will we ever see your videos again?

[@omprakashraja2300]

I have a question. Suppose I filled solar evacuated glass tube with sand and closed the open mouth by thermal insulator. And placed these solar tube in sunny day for couple of days. What will be happen? Solar evacuated glass will explode or Sand temperature will constantly increase or Solar evacuated tube refuse to absorb more radiation after achieving same temperature by Sand. What will happen? Please explain.

[@ushillbillies]

love your stuff Man..,hello to misses..

[@johng.3740]

"Heat" which is in essence a transfer of energy, can be transferred through 3 basic means: 1. Radiation - like Sunlight 2. Convection - Air in contact with a hotter element will heat up and rise, bringing in colder air. 3. Conduction - An object in contact with a hotter object on one end and a colder on the other end will transfer heat from hot to cold. So when a vacuum is created inside a tube and exposed to sunlight, radiative heat is transferred to the tube. Yet because the tube does not have any air inside and is not in contact with the walls the heat has only one way to escape, through radiation, which due to the frequency shift of radiation is inefficient. Hence this is why heated vacuum tubes make very efficient energy collection and storage devices. There is a way to control the amount of pressure in the system and the total amount of heat collected and that is to put movable covers over the tubes so that only a measured amount of sunlight strikes them and to the move the fluid through the tubes. Vacuum solar power collection tubes are probably the most efficient way to turn sunlight into electricity. More importantly, appropiately engineered vacuum solar collection tubes with allowances made for high pressure, can be used to produce high pressure steam. The high pressure steam can then be used to turn a turbine, the turbine can then be connected to an electric generator. The excess steam can then be used heat an absorption refrigerator or air conditioning unit, finally the steam can then be used to heat water. I saw a comment in the comment section in regards to a water and scale in this vacuum solar collector system, there is a very easy way to over some this and that is to used distilled water and/or water passed through a reverse osmosis system.

[@karmanyabhandari7118]

but it takes little bit more steam to run a steam turbine.

[@danrobins4750]

Why does the cardboard not catch on fire if the sand is so hot?

[@wingerrrrrrrrr]

Needs to be hotter, like 451 Fahrenheit

[@Zomby_Woof]

Why use glass for the tubes? Acrylic tubing would be a better choice. It's stronger, tends not to shatter, and transmits more light than glass.

[@JuanSanchez-ik7wx]

glass tubes are double pane. Are the acrylic tubes double pane?

[@Zomby_Woof]

@@JuanSanchez-ik7wx They can be as many paned as you want them to be, by putting tubes in tubes.