Storing wind-produced heat in a mass to heat a home?

I had a thought after reading about Rocket mass heaters . Why not use a windmill to heat a "mass " ? heating need not be all the time with a clay mass you just keep topping up the heat as the wind blows .
A practical idea ? bit like the old electric storage heaters only on a bigger scale and cheaper to run .
Any thoughts or just a silly idea? It would seems to be solution to the intermittent nature of wind power .

David

David L. : I had a friend explain a windmill scene that refused to accept the idea of a wind mill that had extra elect that you sold to the grid and bought back retail !

The idea was to use gearing to churn paddles in an oil bath, turning mechanical energy to heat energy, no extra Electrical power step with increased Energy losses !
I can't ask this old submariner abut this again He has gone to heaven for 'mariners - A long tube full of Seamen ! Big Al

Induction heating is when a moving magnetic field or fields heat a stationary metal surface. The induction burners seen in infomercials uses grid power to run electromagnets beneath a pot or pan. Supposedly, this is more efficient than cooking over an electric burner because the heat is generated directly in the cooking pan or pot, rather than convecting into it from a heat source beneath it.

Moving magnets quickly by a ferrous metal surface also heats the metal, and whatever is inside it.

Seems possible to use the motion from a windmill to move magnets at a high speed. If those magnets were in proximity to a ferrous metal vessel, it should heat that metal, and whatever is inside it; water or thermatic oil, maybe.

The theory is sound. Transferring the motion "up there" at the turbine down to where you want to use it would be a matter of engineering and calculation of losses of mechanical energy in that transference from up high to down low. Gearing would also be needed to get the magnets spinning fast enough to heat whatever metal vessel is chosen.

I've never even heard of anyone attempting to use a wind turbine to run an induction heater, so it's an unknown combo, as far as I know.

If the losses weren't too great, perhaps a wind-driven induction heater could compete with an electric generating wind turbine.

I'll grant that's a big if, but it seems like an interesting idea.

A hazy idea that made me think of this is to use an electric fan, with ferrous blades, in close proximity to stationary magnets. My theory is that the blades will heat up as they pass magnets mounted to the cage. The result should be warm air blowing from the heated blades.

It seems like a way to turn an ordinary electric fan into a heater. I have no idea how much more electricity the fan will draw due to the attraction forces of the magnets acting against the rotation of the blades. Quite possibly wouldn't be efficient enough to be worth the effort. Then again, until someone actually tries, we won't know for sure, will we?

It's an experiment I want to try some day with an old-school metal fan I have here.

If you look up "DIY induction heating" on YouTube you should find a few water boilers that operate on this principle. It's interesting, if nothing else.

I think maybe I have not been clear here .
Windmill to produce electricity ,electricity to produce heat , heat stored in a heat sink or "mass"
Heat sink to heat house .
Trying to turn motion directly into heat seems a none starter to me .

David

You would need a very large windmill and a very small house.
In other words, not gonna happen.

Best source of heat out there is the sun. Then burning things. All the other ideas to use alt energy to heat stuff (be it water, homes, cooktops, etc) is pretty unrealistic.

Turning motion directly into heat would be a better idea if feasible; you'd avoid all those conversion losses. Seems like a water brake would do the trick.

David Livingston wrote:I think maybe I have not been clear here .
Windmill to produce electricity ,electricity to produce heat , heat stored in a heat sink or "mass"
Heat sink to heat house . :-)
Trying to turn motion directly into heat seems a none starter to me .

David

Victor -Think of this as a thought experiment, go down cellar to the fossil fuel fire Hot air furnace and open the blower compartment while the blower is on! 95%
-ish of the time you will fight against a suction holding the door in place due to imbalances between the hot and cold air ducting ! If you test the current draw with the
door on and the door off, you will find that the electrical motor, when unable to move air due to restricted flow to the blower cabinet, draws less current than the motor
pushing air without this restriction ! In this case increased current draw equals more work done !

So With a viscous fluid the Blades should be working harder than when pushing Air ! With a direct drive, except some heat lost at the bearing blocks all of the work energy
should generate heat in what ever medium we are churning our paddles through ! As Adam alludes to there is a point that the wind mill will stall if we ask it the do to much
in light winds -this would also occur with a generator being driven by our wind mill !

I started out to talk about, not giving electricity to the grid wholesale and buying it back retail, with a hefty charge for being connected to the Grid !

Our direct drive system is an immediate energy dump collecting and storing energy at a central location, the only other feasible energy dump to not loose energy in our
electrical wiring is at the batteries, not always the best place for raising the temperature above ambient !

With David's plan, we would have heat build up in 2 or 3 locations, at the direct drive/generator interface due to inefficiencies, at the batteries, same story here, and hope
-fully at a remote location where the 'normal' inefficiencies of flowing electricity work in our favor and generate heat and a little light !

As energy can nether be created or destroyed we end up with nearly identical heat profiles one slightly more centralized and stored at at higher temperature !

Under ideal conditions the electricity energy that Davids conventional system can create from mechanical energy, can be used to run a heat pump getting a Return On
(energy) Investment. R.O.(E.) I., that can be as high as 5 to 1 !

For the Good of the Craft ! Be safe, keep warm ! As always, comments and questions are solicited and are Welcome !

David Livingston wrote:I think maybe I have not been clear here .
Windmill to produce electricity ,electricity to produce heat , heat stored in a heat sink or "mass"
Heat sink to heat house .
Trying to turn motion directly into heat seems a none starter to me .

David

Why do you see the direct approach as a non-starter, David? I'm exploring options and open to all sorts of possible applications, but in that process it's important to get the cons along with the pros

Seems to me the more times you convert a form of energy, the less you will end up with for your application, so kinetic to heat without the back and forth to and from electric saves two steps.

Its the practicality of turning the kenetic energy of the wind into the heat sink . The other ideas seem to involve turning the kinetic energy of the wind into heat in a liquid which either becomes the heat sink ( doubt this would work as it would loose heat to fast to be a good sink) or then transfer the heat some how to the heat sink ( so there is a hidden transfer here)

David

Dont forget about heat pumps. They heat AND cool without bringing dangerous combustion devices into the home. Its tough to match the power and efficiency of phase change refrigerants.

I've looked at this also. Here's where I got to:

Wind generator @ 12vdc or 24vdc
RV water heater element(s) (they come in either voltage at 300 to 600 watts)
large (in my case 300 gallon tank) metal tank

Wind turns generator, electricity heats element(s), water warms in tank, tank is in shop, and radiates to warm bodies. Wind blows here 24/7 quite often in the winter.

I looked quite some time for direct kinetic to heat, considered friction (paddles in oil is one method). Induction is a great idea and I'll give it some thought.
I've all the components for the water heater, just need to erect a pole for the generator. Most likely will have it operational for evaluation this autumn.

I'm new here, but joined this forum after reading this post about heating with a wind turbine. Basically, it's not going to work all that well. Whether the turbine generates electricity that is converted to heat, or uses shaft power to create eddy currents in ferrous metals to create heat doesn't matter. One kW of energy (either mechanical shaft power or electricity) for one hour, converted to heat at 100% efficiency, will create about 3,410 BTU of heat energy.

So you need to to the math on BTU requirements for your heating to determine how large the turbine has to be in order to be practical. Basically, it's going to take a very large and expensive turbine to heat even one small room in your house in the winter time.
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Chris

The nice thing about wind is that it doesn't just blow for one hour. With an appropriate storage and dissipation mechanism, even small amounts of wind energy over long periods will accumulate to provide usable heat.

I think that for non-earth sheltered housing/work spaces, multiple "heat generation streams" coupled with good insulation mitigate the failure/non-performance of any single stream.

Bill Kearns wrote:The nice thing about wind is that it doesn't just blow for one hour.

Of course not. But the typical wind turbine that develops 2 kW @ 28 mph will produce about 250 watts at 12 mph average @ 1,100 ft elevation. Less at higher elevations. 12 mph average wind speed is an extremely good wind site. The more typical average on most sites that are considered marginal good for wind power is 8-10 mph. But assuming 12 mph average, the turbine will produce 6 kW in a day, which is possible to turn into 20,400 BTU of heat energy at 98% efficiency with resistive heaters. That is only 850 btu.h which is approximately equivalent to the heat output of a parafin candle. Considering the fact that a 2 kW turbine installation on a 90 foot tower is going to have an entry cost of $10,000, it is a very expensive source of heat.

Our last turbine and tower that I put up here last July is a 90 foot free-standing lattice-type and the engineering stamps on the tower and foundation (required for zoning) cost us $7,600 JUST for the paperwork. But our turbines generate electricity to charge our battery and they typically produce 30 kWh/day in the winter time when we get no solar for up to 6 weeks at a time. Even though we got over $30,000 invested in wind power here, it's still cheaper than generators and diesel fuel in the winter. That's an application where wind power is practical because there is no other source of power for our off-grid home in the winter that costs less. But when it comes to heating, basically I can get more BTU out of two chunks of red oak burned in the wood furnace for a day, for a cost of nothing, than I can out of a $15,000 wind turbine.
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Chris

Chris Olson : I agree emphatically with everything you say ! Opps, except that you will lose wind speed with height, make that Can, in fact much work is being done with anchored
Ballons, Especially on Hawaii's Big Island ! The biggest problem seems to be getting permits from the F.A.A. !

I have no figures at all for Kilowatts generated on and off the grid, so this is only what I think, but most of the programs to help people gain wind or solar energy require being
tied to the grid, in that case, you are locked into a system where you are selling your immediate surplus Electrical Energy to the Utilities Wholesale, and buying it back retail - At
this point you have to decide if you are happy with this arrangement !

There are some people like myself who would love to minimize the amount of power 'lost to the grid' in this manner, So after your batteries are at maximum charge what are you
going to do?

1 ) Do nothing, your grid hook-up will automatically dump your excess power onto the grid !

2) -Available if you have a drive shaft that delivers mechanical power to the base of your tower, use a direct drive to drive any piece of equipment in an effort to use up every last
erg, rather than 'give it to the Utilities' Hot oil is a doable heat sink, but you are increasing wear on your system, and you are dependent on wings that 'blow' at a useful speed !

3) Physically lock-out your 'turbine' or Feather It ! This depends on how your system is designed and may occur as soon as your batteries are 'full' and should save on wear and tear !

4) Some systems are set up to allow ether an Automatic or Manually activated, Resistance Dump that by placing a load onto the system keeps the windmill/turbine from free -
wheeling and inducing wear with zero gain ! This is very common with none grid tied systems and is basically added as it will save Batteries !*

5) The only 'over unity system' - The 'Heat Pump' - that we will probably ever be able to have, and that will work with the Thermal Mass that was mentioned with the original post,
when our batteries are again 'full' we can run a dedicated heat pump, to store heat energy (or Coolth) in a location in our house of our own choosing and get a 'return on investment'
of the Electricity that we started out to 'Not Give away' in the 5 to 1 class Some additional wear on the system !

For the Good of the Craft ! Think like Fire!, Flow like Gas, Don't be the Marshmallow ! As always, your comments and questions are solicited and are Welcome ! Big Al

* you may even have a resistance dump built into your own system !

allen lumley wrote:
4) Some systems are set up to allow ether an Automatic or Manually activated, Resistance Dump that by placing a load onto the system keeps the windmill/turbine from free -
wheeling and inducing wear with zero gain ! This is very common with none grid tied systems and is basically added as it will save Batteries !*
* you may even have a resistance dump built into your own system !

We do not have grid available to "dump" power into.

We have Classic 150 MPPT controllers, made by MidNite Solar. The controllers, when used on a wind turbine application, have a programmable power curve and voltage clipper that prevents the voltage from exceeding 146 volts. When the battery bank is charged and turbine power is not needed to meet loads, the controllers shut the turbines down to prevent wear and tear on them.

My wife will not allow a propane tank on our property, so we do everything with electric, including water heating. We have a Schneider Electric Conext/Xantrex XW power system, 120/240V split-phase. While the elements in the water preheater are "opportunity loads" for when we have excess power, the primary water heater is powered all the time on 240V from the inverter, and controlled by the thermostat like any normal water heater. We also have a high-efficiency electric range with induction cooktop and convection oven. But all our home heating is done with wood, with a catalyst equipped central forced air wood furnace. We do not use solar heating because it doesn't work in the winter time when we need it the most.

Wood is an environmentally sound choice for home heating. It is a carbon-neutral fuel, and is the oldest heating fuel known to man. Trees only live so many years anyway, so we try to use a select-cut harvest of mature hardwoods for firewood in our woodlands. This also removes the dense canopy to let sunshine thru so the undergrowth and young trees can get established. The reason I say we "try" is because invariably our home heating needs are not great enough to keep up with trees that die from natural causes, usually old age. We try to get those and process them before they get rotten and tip over. But we have over 500 acres of woods on our property. So in the long run we are not able to use all the firewood that could be available to us, just from dead trees.
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Chris