Turning kinetic energy from wind directly into heat (hot water)

For a long time I've been cogitating (that's what old codgers do ... cogitate) on determining the best method to turn kinetic energy directly into heat ... specifically how to directly heat water with wind energy.  Most of the ideas I've seen involve generating electricity to power resistance heating elements, but this is SO inefficient!

Then this morning it hit me:  FRICTION
Friction is the method to turn the rotating wind-driven power directly into heat!  I began thinking of direct metal-to-metal contact immersed in water ... i.e., a rotating shaft powered directly from the wind turbine in contact with a stationary metal disc immersed in a water tank.  Eureka, the tank wouldn't even have to be sealed!!  Water would cool the friction-heated discs (and store the heat).

So now I'm stoked and wondering about what metals to use for the friction surfaces.  Steel to steel?  With the water cooling, couldn't they still weld themselves together?

Any suggestions for materials here?

Mollison mentiones something like this in Introduction to permaculture:
files.uniteddiversity.com/Permaculture/Introduction_to_permaculture.pdf

Look on page 72.

He says:
You make heat from wind
using a simple device--a vertical axis windmill that stirs the wa-
ter kettle inside the house. It has a kettle with fixed vanes. The
force of the wind creates a tremendous turbulence. It gener-
ates heat. The colder it blows, the hotter it gets. Canadians use this technique .

Friction is wasteful because you will have to replace the metal parts as they wear away. 

Lhtown  is right - direct heating of water is the way to go.  If you run a fire pump with the valves closed, you will boil the water in the pump.  That's the effect you want.

You will want the pump to circulate a bit of the water, so you can use the heat somewhere away from the windmill.  But if you use a big pump, and just a small outlet, you will be heating the water directly.

[size=8pt][Edit: spelling][/size]

Even with the water, you will still have some wear on solid parts. You would want to make sure there is no grit or sand in the water. Other liquids, gels, or even gasses could be used instead of water..

9andolf maybe your ideas would still find a way to translate if there were no metal to metal contact .  I know nothing  so I googled air friction and read about lightning and thunder

http://www.space.com/scienceastronomy/lightning_backgrounder.html

If the air drag from currents (essentially a type of friction right?) can create such powerful energy forces , well maybe on a small scale you can use the friction from say a wind driven paddle in a water vat without the source of the friction being metal against metal that would wear.  We generate electricity with turbines  but do they generate steam?
Sorry I am absolutely ignorant on the subject, but your post caught my attention as I always admire people experimenting to find a better solution. 

Synergy,
You lead us into an important point. If you do try this type of system, make sure you avoid any static buildup through proper grounding, choice of materials and whatever else. You don't want to die of self-induced lightning.

Makes me think of this, though I am prone to disbelieve the over unity claims.


How do i embed video?

Unless I am missing something, it seems like this would be ultra low tech given that the object is to create friction.

Areas for improvement would be to reduce the size, cost, environmental impact, and complexity of the friction unit, increase system longevity and reduce maintenance intervals, make it come up to temperature faster or retain heat longer, distribute the heat efficiently throughout the building, and perhaps most importantly increase efficiency of wind capture including efficient energy capture at a range of speeds.

It does seem like this would be a good way to provide auxiliary heat to a solar greenhouse.

Wow, thanks for all the good information and ideas!  I came across this friction idea when removing a small nut from a screw that had been sitting for a while and was a little rusty.  After only a few turns the thing was too hot to hold in my hand!  I would imagine that friction could approach near 100% efficiency in turning kinetic energy directly to heat.

I'm especially intrigued with the application of friction at a molecular level (i.e., stirring the water, which turns out to be "liquid friction" for the purposes of google searching).  Leave it to Mollison!  Any "Canadians" out there using this technique? 

Again I am way out of my league , I never took physics , so bear with me,  but could a wind powered paddle stirring water, you would have the friction of the paddle but also the water against the container, could it possibly warm the water enough to use in a circulating warming/heating type application or might it be totally insignificant? 

It could have enough energy to make steam. It just depends on how much energy you put in. Whatever you put in is what you will get out.

You can't really just put a paddle in a barrel though. The water would swirl with the paddle and not make much friction against the smooth sides of the barrel. You would need to put stationary vanes on the side of the barrel to slow down the water to make more friction.

Perhaps you could adjust the vanes according to the paddle speed to help keep the wind turbine moving at optimal speeds.

The ingenious among us could probably come up with a paddle design that didn't require stationary vanes. Perhaps some sort of screw...

Some of the good wind-to-thermal turbines amount to a wind-driven condenser on a vacuum distillation system.

A reservoir of water is held in a somewhat-warm location, that is to say a large reserve of low-grade heat. A vacuum line runs from this to the wind turbine. The turbine pumps on the vacuum line until water in the reservoir boils (or sublimes, if the reservoir we're drawing heat from is really cold...in that case, you can have a freeze-drying rig combined with your wind-to-heat scheme).

The low-pressure water vapor in the vacuum line can also be warmed somewhat by low-grade heat as it travels, to bring it up above the low temperature it now has due to evaporative cooling.

The turbine, in the process of pumping on the vacuum line, condenses the water vapor, releasing its latent heat of vaporization. This water can then run down the tower of the wind turbine in an insulated pipe, depositing that heat in a not-too-far-off location.

Found some more information on mechanical "stirring" of a liquid to create heat directly.  Seems the active mechanism isn't so much friction as it is cavitation ... essentially "stirring" in such a manner to create voids in the liquid (bubbles of vapor) that collapse and release heat.  Google search is "cavitation heater" and this thread on the Otherpower forum has pics of one such device:  http://www.fieldlines.com/board/index.php/topic,129151.html   Most fluid/mechanical design is concerned with reducing/eliminating cavitation so I'm searching for works on how to create it.

(I noted that there are many claims of over-unity energy gains from cavitation heaters ... but we obey the laws of physics in this house!  )

I also noted that there is erosion of the metals involved, but then again the eroded areas cause increased cavitation!  http://en.wikipedia.org/wiki/Cavitation

Since I have a metal lathe and need a winter project ...    maybe some experimentation is in order.

(edit to fix link)

Wow,  I really am amazed, you have to keep us up on how it goes. That is exciting, I watched those videos before , I look forward to hearing if it works for you .

Wind power would be superior here in my microclimate  as I live on the crest of hill where the wind funnels up a valley a few miles off the west coast. 

I am far, far lower tech , so I am working on a solar  hot air heater made with aluminum cans that I saw on You tube.  that is about the extensiveness of my grasp of physics  and tools , but it is a start  : )

Might I recommend brass or bronze over aluminum, in your cavitation heater. The erosion process is one of metal fatigue, so fatigue-resistant alloys will last longer.

Peening the surface will both help increase the rate of cavitation, and help reduce the rate of erosion, similar to the way it helps protect the edge of a scythe from wear. Maybe something narrower and more precise than a ball-peen hammer, perhaps a tool that resembles a nail set but has a 1/4" radius spherical tip.

Bill, I second (or third) the idea of "stirring" water contained in an insulated vessel for heating. See Joule's work in thermodynamics during the 1800's. Cavitation is not required, but may be unavoidable. Any resistance to the motion of the "paddles" contained in the vessel will transfer energy to the water to raise its temperature. I used to work at an experimental power plant that placed a large "water brake" on the output shaft as a load. The same principle applied there even though it was basically a large hydraulic pump that sent the water through a restriction. On that note, you could drive a vane pump (hydraulic) with the wind turbine sending the discharge of the pump through a pressure relief valve, and contain the whole apparatus within an insulated vessel. If the vessel were pressurized, then this could help minimize any cavitation in the pump.

However, note that wind turbines generally have to be elevated for good performance. Therefore, there would be extreme thermal losses involved in containing the heated water and especially in transferring the heated water to an end use. I expect the losses to be greater than those seen by a good alternator. So, it makes more sense to use the wind turbine to drive an alternator, then send the DC output directly to a water heating element. This is often done as a "dump load" in diversion battery controllers, but in this case one would just connected the alternator directly to the element and call it a day. If it's heat from wind that you want, then this is actually an elegant solution.

I didn't notice this mentioned so I'll throw it out there.

Induction heating. Moving magnets will heat a ferrous metal container from eddy currents, if I understand correctly. Since the windmill is already spinning, maybe you can find a way to spin magnets by a ferrous container. The stronger the magnets are and the faster they go, the more heat.

About 25 to 30 years ago I designed a brochure (I'm a graphic designer) for a start-up company headed by a former aeronautical engineer who used to specialize in aviation transmissions (I didn't even know that airplanes had transmissions). He said his former enemy was always the heat generated by two sets of veins, paddles, blades rotating at different speeds. It made dangerous amounts of heat at the high RPMs that those engines operate at. After retiring he realized that the same enemy could be used to generate heat directly from motion for domestic use. When I was doing the brochure for him he had developed a system that used an agriculture style windmill with a vertical shaft that transferred the motion of the windmill down to a transmission box buried in the ground. The box was basically a transmission box with one set of blades immobilized. The friction in the transmission fluid made lots of heat that was transferred to water via a heat exchange coil into a tank. The pipes from the windmill to the house had to be well insulated but that was the gist of the whole concept.

I moved from there shortly after doing the brochure so I don't know if the company ever succeeded but I'd love to find out if any such set-up is commercially available. Failing that, I'd like someone's ideas on converting a transmission into a heat generator.

What say ye?

Michael Shumate wrote: Failing that, I'd like someone's ideas on converting a transmission into a heat generator.

What say ye?

It seems easier to use a hydraulic pump for this purpose. Whatever energy is dissipated in the system will be converted to heat. The goal is to dissipate the energy within the confines of a small highly insulated volume. This will result in the fluid temperature rising. It's possible to control the "gearing" of the pump by varying the position of a valve in the fluid circuit and thereby find the ideal setting for existing wind conditions. A way to visualize this basic concept is to consider a vertical shaft connected to paddles within an insulated drum. The shaft turns the paddles to stir the fluid inside the drum. The fluid in the drum will heat up.

I say it's a bad idea to convert wind energy directly to heat. First of all, it's not going to be any more efficient than using electricity. A wind turbine can be used to generate electricity directly to convert the energy in the rotor at 80%+ efficiency and transfer this electricity to resistance heating elements. The thermal losses from heating a fluid and transferring it to a heating application will likely be higher than this. More important, it's a lot easier to use wires to transfer the energy vs. long vertical drive shafts and insulated piping. Finally, there isn't all that much heat available from such a process unless one uses a massive turbine. If someone were dead set on providing heat with a wind turbine, then make electricity to power a heat pump.

Michael Shumate wrote:About 25 to 30 years ago I designed a brochure (I'm a graphic designer) for a start-up company headed by a former aeronautical engineer who used to specialize in aviation transmissions (I didn't even know that airplanes had transmissions). He said his former enemy was always the heat generated by two sets of veins, paddles, blades rotating at different speeds. It made dangerous amounts of heat at the high RPMs that those engines operate at. After retiring he realized that the same enemy could be used to generate heat directly from motion for domestic use. When I was doing the brochure for him he had developed a system that used an agriculture style windmill with a vertical shaft that transferred the motion of the windmill down to a transmission box buried in the ground. The box was basically a transmission box with one set of blades immobilized. The friction in the transmission fluid made lots of heat that was transferred to water via a heat exchange coil into a tank. The pipes from the windmill to the house had to be well insulated but that was the gist of the whole concept.

I moved from there shortly after doing the brochure so I don't know if the company ever succeeded but I'd love to find out if any such set-up is commercially available. Failing that, I'd like someone's ideas on converting a transmission into a heat generator.

What say ye?

Directly heating is very good and efficient. Converting to other energy forms (electricity for example), always has extra losses and complication and cost.
A windmill that stirs paddles in a baffled container filled with water. The baffles preventing the water from simply spinning round. I do believe that in Sweden many years ago, some off grid housing used such units to heat the houses, day and night, with their windy winters.....
There are people making specialised rotors in the USA to do this very efficiently. Boiling water is easy to produce with no fuel needed if the wind blows. See here:-

There are plenty of these to look at.....
Even a simply DIY version in an old oil barrel will deliver useful heated water.....
Regards

“The one common thread I've seen is their not recognizing the fundamental difference between heat and temperature, which is an elementary misconception.”

Heat is the amount of total energy contained within an item; both potential energy and kinetic energy. Potential energy is stored energy and kinetic energy is moving energy. Temperature is a number that corresponds to the amount of kinetic energy in an object. When heat is introduced into a system, molecules move faster. When molecules move faster, they bump into each other harder and more often. These measure of the energy of these collisions is temperature. So, temperature can result from heat being introduced into an object; that is, heat is energy introduced into a system and one affect heat can have is to increase the temperature. Heat introduced into a system can also cause a phase change; like ice melting into water, with no subesquent speeding up of molecules, and therefore no temperature change.

If we were ranking different forms of energy, heat would be the one on the bottom. Without a lot of expensive gadgetry, it remains as heat. Compressed air can be turned into heat if desired, or it can generate electricity or power many devices directly. This thread concerns using an air compressor run directly from a windmill. You still get the same amount of heat, with the added benefit of having compressed air available, which eliminates the need for most of the electricity commonly used in a home.

Windmill with air compressor instead of electric generator --- https://permies.com/t/9902/wind/Windmill-air-compressor-electric-generator

Once the pressure vessel reaches maximum storage capacity, the excess power could be dumped into a water heating system as described in previous posts.

Far more heat(about 3 times as much) could be produced if the windmill were used to power a heat pump. Electric heat pumps turn that energy into motion. It could all be done right off the shaft from a windmill.

In the UK the larger wind turbines 7MW are moving away from direct generator connection due to the size of the gearbox needed. Instead hydraulics are being used which as a byproduct produces usable heat for other processes.

r john wrote:In the UK the larger wind turbines 7MW are moving away from direct generator connection due to the size of the gearbox needed. Instead hydraulics are being used which as a byproduct produces usable heat for other processes.

Interesting. I suppose hydraulics are used as a transmission system that can be on ground level as opposed to supporting a gear box and alternator on the tower. Of course, providing heat is not the purpose of the system, but what processes are using heat generated on site?

Marcos Buenijo wrote:

r john wrote:In the UK the larger wind turbines 7MW are moving away from direct generator connection due to the size of the gearbox needed. Instead hydraulics are being used which as a byproduct produces usable heat for other processes.

Interesting. I suppose hydraulics are used as a transmission system that can be on ground level as opposed to supporting a gear box and alternator on the tower. Of course, providing heat is not the purpose of the system, but what processes are using heat generated on site?

Using hydraulics enables a slow pump but high speed motor and therefore does away with the gearbox but still in the nacelle. Obviously heat is generated in the hydraulic fluid which can be stored and used on demand to generate electric.

r john wrote:Using hydraulics enables a slow pump but high speed motor and therefore does away with the gearbox but still in the nacelle. Obviously heat is generated in the hydraulic fluid which can be stored and used on demand to generate electric.

Yes, it makes good sense to use hydraulics in this case for transmitting mechanical energy to a hydraulic motor coupled to an alternator on the ground. Hydraulic pumps can be surprisingly compact and lightweight for their power. However, I encourage you to reconsider your second statement. Do you claim this is being done (waste heat converted to electricity), or are you only noting that this could be done? I don't see the additional electricity as justifying the additional costs involved.

quote=Dale Hodgins]If we were ranking different forms of energy, heat would be the one on the bottom. Without a lot of expensive gadgetry, it remains as heat. Compressed air can be turned into heat if desired, or it can generate electricity or power many devices directly. This thread concerns using an air compressor run directly from a windmill. You still get the same amount of heat, with the added benefit of having compressed air available, which eliminates the need for most of the electricity commonly used in a home. Windmill with air compressor instead of electric generator --- https://permies.com/t/9902/wind/Windmill-air-compressor-electric-generator
Once the pressure vessel reaches maximum storage capacity, the excess power could be dumped into a water heating system as described in previous posts.
Far more heat(about 3 times as much) could be produced if the windmill were used to power a heat pump. Electric heat pumps turn that energy into motion. It could all be done right off the shaft from a windmill.

Hello Dale,
Further to your remarks having a windmill drive an air compressor. Defying the law of 100% efficiency in energy conversion 222% is now modelled.

Air introduced to a water container forces the water out the bottom and up to an overhead tank. In so doing the water passes to an 82% efficient Pelton hydro turbine. The compressed air then changes place with the water which returns to its original spot after passing through a 82% efficient Francis turbine. The compressed air then passes through a 60% efficient gas turbine.
Air compressed to 100 psi forces water at 100 psi through the two hydro turbines then the air still at 100 psi passes out through the gas turbine.

Marcos Buenijo wrote:

r john wrote:Using hydraulics enables a slow pump but high speed motor and therefore does away with the gearbox but still in the nacelle. Obviously heat is generated in the hydraulic fluid which can be stored and used on demand to generate electric.

Yes, it makes good sense to use hydraulics in this case for transmitting mechanical energy to a hydraulic motor coupled to an alternator on the ground. Hydraulic pumps can be surprisingly compact and lightweight for their power. However, I encourage you to reconsider your second statement. Do you claim this is being done (waste heat converted to electricity), or are you only noting that this could be done? I don't see the additional electricity as justifying the additional costs involved.

Dont have inside knowledge on the 7MW turbine but with any large hydraulic system you always have some kind of oil cooler or heat exchanger. Technology for turning hot thermal oil into steam is what I use in power generation. Applying the same technology to a hydraulic wind turbine would only require a steam hydraulic oil pump as the existing power train would be utilised for power generation. If you look at Windflow NZ wind turbines they use a hydraulic pump system to smooth the effect of gusts on power output using there existing power train.
The 7MW turbine in the uk has 2 generators in the nacelle not on the ground.

r john wrote:Dont have inside knowledge on the 7MW turbine but with any large hydraulic system you always have some kind of oil cooler or heat exchanger. Technology for turning hot thermal oil into steam is what I use in power generation. Applying the same technology to a hydraulic wind turbine would only require a steam hydraulic oil pump as the existing power train would be utilised for power generation.

Ok, so it seems you're only pointing out that it could be done. Sure, I don't disagree, but I don't see the prospect as being cost effective. Allowing the hydraulic fluid temperature to rise to the point where electricity generation might be sufficiently efficient would require more expensive fluid and seals, insulation, and more frequent fluid replacement - increased costs. I don't see it likely that the additional expense would justify increasing the net electrical output on the order of 1%. Of course, I would like to something like that just for interest. NOTE: Large hydraulic systems often do not provide dedicated oil coolers. Rather, the heat dissipation afforded from the ventilation in the spaces and expanse of uninsulated piping and tanks is usually enough to cool the oil sufficiently. Of course, this depends on the system.

Marcos Buenijo wrote:

r john wrote:Dont have inside knowledge on the 7MW turbine but with any large hydraulic system you always have some kind of oil cooler or heat exchanger. Technology for turning hot thermal oil into steam is what I use in power generation. Applying the same technology to a hydraulic wind turbine would only require a steam hydraulic oil pump as the existing power train would be utilised for power generation.

Ok, so it seems you're only pointing out that it could be done. Sure, I don't disagree, but I don't see the prospect as being cost effective. Allowing the hydraulic fluid temperature to rise to the point where electricity generation might be sufficiently efficient would require more expensive fluid and seals, insulation, and more frequent fluid replacement - increased costs. I don't see it likely that the additional expense would justify increasing the net electrical output on the order of 1%. Of course, I would like to something like that just for interest. NOTE: Large hydraulic systems often do not provide dedicated oil coolers. Rather, the heat dissipation afforded from the ventilation in the spaces and expanse of uninsulated piping and tanks is usually enough to cool the oil sufficiently. Of course, this depends on the system.

I cannot believe this attitude I know the US is very wasteful when it comes to energy but heat recovery systems are pretty standard in UK. As for more expensive hydraulic fluid or improved seals and more frequent fluid replacement that is just rubbish. We even have an oil cooled rather than water cooled engine so that we can recover the waste heat in a useable manner rather than just cooling to the atmosphere. It might only be an extra 1 or 2% generated but on a 500kw machine every little helps.

r john wrote:I cannot believe this attitude I know the US is very wasteful when it comes to energy but heat recovery systems are pretty standard in UK. As for more expensive hydraulic fluid or improved seals and more frequent fluid replacement that is just rubbish. We even have an oil cooled rather than water cooled engine so that we can recover the waste heat in a useable manner rather than just cooling to the atmosphere. It might only be an extra 1 or 2% generated but on a 500kw machine every little helps.

It's all about cost. If the additional electricity generated by this low grade heat recovery can be more valuable than the additional costs involved, then it makes sense. All I'm doing is expressing doubt about this possibility. What I consider is that the temperature of the hydraulic fluid has to be considerable to ensure high thermal efficiency and to minimize the size (and cost) of the heat exchangers required. It's a catch 22 as beyond a certain point there will be a concern about fluid stability over time and the integrity (and cost) of seals. Consider that hydraulic components are not normally rated for temperatures normally used in power generation. Of course, a system that can convert the waste heat in a hydraulic system to electricity, and do so economically, would be fascinating to see. However, skepticism about its viability seems to be the rational consideration.

Now, if low grade waste heat carried by warm hydraulic fluid can be put to use on site for heating applications, then it seems to make sense. This seems unlikely for large wind turbines that are generally placed in remote locations.

Hello Marcos Buenijo,

“It's all about cost. If the additional electricity generated by this low grade heat recovery can be more valuable than the additional costs involved, then it makes sense. All I'm doing is expressing doubt about this possibility”

CO2 has 1 bar pressure at -40*C, this pressure increases with temperature, 10,000 bar at +100*C.

Being a fridge as well as a turbine generator it chills the boiler return liquid and if allowed would freeze it.

Thank you Markus.

DaS Energy and American NASA first published on CO2 in 2002. Coles Supermarket freezer-fridges are now CO2, plus there a web site R744.

Stainless Steel make pressure vessel, called the boiler pump in absorption fridge. restricting the pump pressure is a restrictor with purpose to
take away the gas pressure so it turn cold. Turbine also does this. The cold liquid or gas R744 (CO2) in place of making the beer cold goes
direct back to the boiler pump. At such point of hot and cold between -40*C and +100*C hot one litre per second of 9 Bar pressure produces 720 watts.

Search out - DaS Energy Turkey. I believe we have a language barrier here. I have searched out some of Peter's other posts which reference DaS energy. They have working prototypes and consumer models of many alternative energy products. My mobile phone won't produce a link.

Peter, were you involved in developing any of these products ?

Hello Dale,

I am the D in DaS Energy, and heavily involved in all from the start.

Thank you for your compliment. We are attempting to achieve change for the better,
and feel that be best done by putting things in the hands of the people, which why nearly
all our work can be home built with every day tools.

Not many industries not know of our work with piston engines and turbines. The DaS Valve
essential in combustion engines was gifted to the Australian people, and the Clerk of Parliament
is waiting on the model to put on display. This now being passed over.

Coal is very much up in arms given Coal is a fuel of the past when CO2 takes over the job of steam.

Ford and Holden turned down the new engine design having three moving part and only friction being
water rub on the cylinder walls. Combustion heat turns water to steam inside the engine. Government
wont allow heating above +600*C 200 bar (2840 psi) force each stroke as that cuts into defence knowledge. So Diesel fuel
1200*C is out. Though lesser calorie fuel is in.

Volkswagen never did reply to our combustion engine offer but changed its advertising to be Das Auto.

Regards

Peter