Wind power for electric heater.

[ecomodded]

My plan is to get a wind turbine working to
power a electric heater directly.
Doing it this way i can store the heat energy.
When I do not need the heat in my house, i can blow heated air into a insulated large gravel filled heat storage box, continuously circulating and heating the same air. During the night I can use the stored heat energy to heat my house.
I can also add solar heating boxes to add heat to the system when the sun is shining.
I have most of my parts to make the wind generator, a 3000 watt generator off of a gas generator. 3000 watts @ 3600 rpm. I will be pleased to get 1000 watts out of it. I will need to gear the turbine so it can get some decent voltage from average winds. I am planing on a 2 blade design between 10 and 16 ft diameter. As of yet to be calculated,dependent on the gearing i end up using.
This is redneck but, I have a rear axle out of a Jeep Cherokee in my backyard that has a 3.5 to 1 ratio in it, if i could increase the gear ratio more it
would be more effective, regardless it will be a high torque bullet proof gear.
Still in the planing stages and design is everything so i am learning all i can now before i stick this thing together.

[jtbo]

I would think that wind might be useful for that when there is cloudy day, but your planned solar air heaters might be hugely better when sun is shining, so much better that wind power might be very little of help.
For insulation my choice is rockwool, 200mm thickness at minimum, also if you put solar air heaters, make sure ducting is insulated as well and that there are some kind of valves that don't loose heat, so that heat stays where meant.
If you could put argon and sand to heat storage unit it would make best heat storage that currently is, from my memory it was tested to keep heat stored for year without much of losses and being one of least expensive of large energy storage systems.


You would need some kind of mast/tower to get turbine up into wind, that is what has kept me away from wind turbine building as here trees are around me and I would need to get turbine to somewhere 30 meters high, which then would require quite a bit of strength from support structure.

One problem with wind turbines is startup speed, setup you describe can have rather large torque requirement to overcome standing friction and that would cause turbine not to start unless there is enough strong gust, this is what I found to be reality with my prototype of Savonius rotor setup, bearing was freely moving but only when moving, I could not find enough strong gusts to get it start up, but when I helped with hand it did rotate well in wind as long as there was wind.
Just some point that I have rarely been mentioned.

With wind, you don't get much of torque, with Savonius you get more torque but even that is rather small amount, so generally you can get more out from wind by aiming to higher rpm with little restriction.

One good feature might be such that rotor spins freely until at certain speed when generator activates, so it could get started and momentum keeps it going after that even wind would be rather low at times, this would help with issue of rotor not spinning at low winds because generator resistance.

Your location says Vancouver Island, I guess you get good strong winds there? There are some calculators around the internet that can give you wattage of how much wind has energy at different speed, then you can estimate what amount of energy you get from wind with blade efficiency, generator efficiency and so on taken account to, it will not be easy to get 1000 watts with 10ft diameter, my memory tells me that at very strong winds with really good efficiency one might get 1000W with 10ft blade diameter, however it is long time since I did research the stuff. Idea I remember is however that biggest blades that you can put and bit bigger would be good goal

At very low wind speeds smaller might be bit better, but then again Savonius or other similar to that is better when there is little wind, however little wind would be little power and those will not make 1000W at low wind unless one has really lot of them. However I guess you don't need to wrestle with that dilemma, which is here at middle of the forests quite limiting factor, there are handful of days with good amount of wind.

There are many hurdles, but turbine is worth to build if you have wind, it could be used for electricity too if heating proves to be little use, some extra wires and few batteries, LED lights could be run for really long time with such power capacity. Project does sound interesting.

[user removed]

How about using the wind for pumping water and a geothermal well so you could heat and cool the area.

regards
Mech

[Ryland]

The best way to do electric heat is with a heat pump.
A 10 foot rotor diameter should be fine, a rotor diameter of 2.5 meters (8.2 ft) seems to be about what is being mass produced, but for a home built turbine you are going to want a larger collector (rotor) to make up for your other losses with it being home built, check out OtherPower.com if you want to see some awesome wind turbines that are home built and that work really really well, but in reality there are very few unanswered questions about wind turbines, we know what the mass of air is and how much energy is in that air, we know that as speed increased the power in the wind is cubed and we know that to get to that wind that has enough energy to make a wind turbine worth while you tend to have to go up, hence the saying "more tower, more power!"
My main dislike about Savonius rotors is that only half the rotor is doing the work because the other half is being pushed up wind so that half that is being pushed up wind is seeing twice the wind speed as the half that is doing the work, this cuts the size of the collection area in half as well, so where a regular turbine has a large round collection area a Savonius rotor has a very small area that is collecting energy from the wind and it's fighting it's self, needless to say I did see one that was spinning away this last weekend (no load on it) so they do spin... but the rest of the turbines around it were producing near their peek output because of the high winds! so I'm not sure why the owners of this one didn't feel it was windy enough for it to be hooked up to a load and doing some work... but then again they were trying to sell it so they did want it to spin... they sure are pretty when they spin, nice wind art, but if you want one that has a rated output that doesn't break the laws of physics then good luck! so far all of them that I've seen use math that more or less say you could hook a fan to it and have the fan blow on the Savonius rotor to produce more power to run the fan and have some left over! but then again that's just going off the published specs.

[jtbo]

Good savonius needs some cover and a funnel to direct air into it, there are some designs that are hugely better than base design.

However Savonius is not about maximum power, it is about usable power at low wind and when wind direction varies a lot, also when tower is not possible Savonius is good as it does not matter which direction wind comes. But if one wants some big power, like heating, I doubt that Savonius would be good choice, one can't heat with low wind, there just is not enough energy at low wind for that.

Savonius and those old farm waterpump wind mills are good for wind speeds that are below 3 blade turbine startup speed and I think that is only why those would be choices, when one needs to get little power always, but these typical 3 blade rotors are lot better in other situations.

Both concepts have however their places and either type can't beat each other in other one's territory, so there is no reason to dislike them for what they are, only dislike when they are put to wrong use :P

[ecomodded]

I have looked into the Savonius turbine design, it has gathered a lot of bad press, for reasons mentioned by Ryland. I "read" that the Savonius design has been sold to buyers based on its interesting "break through" design.
It sells on its looks but fails on its performance is a repeated theme i have been finding.
Which is unfortunate as it would be less obtrusive & easier to mount, and looks cutting edge. Could be you need to make it really large to work?

The water pump for Geo thermal sounds interesting, I could see making a air-conditioner fairly easy, if i could get to the water. I know my hillside has water under it, but how deep who knows. I could see pumping it up then running it threw a car radiator with a fan blowing threw it.
For the heat i have no clue how to do it on the cheap? any ideas?


I do have wind,Perfect sailboat weather year round. I live at the end of a 20 mile inlet where it blows one direction in winter and changes to the opposite direction for summer.
I am going to check with my city hall to check for any permits that i may need. Using the electric for battery charging may come into play.
The Solar heaters are going to be made in my back yard and in my front yard, back yard first. I still have to work out the heat storage space required for my system. I can get free rock, stone, gravel, boulders so making a large insulated box is half the expense, I can buy most of those supplies from a used building supply outlet near-by.
The Rockwool insulating is interesting, i will have look into its properties & R value, it may well be suited for one of the layers of insulation.
My idea for the box so far is making a plywood box from 5 pieces of plywood , four sides with one cut in half for the ends.
Sit the 4x8 box on 4" of rigid panel insulation that has been half covered with cement, cover the out side & inside of the box with the rigid insulation.
Lay drainage pipe for the air inlet and pipe along the bottom of the box to distribute the inlet air for circulation. The outlet will be on the top middle with more drainage pipe inside to capture heat from all areas of the box.
Wrap it in plastic then stucco wire and more concrete and a sealer.

[jtbo]

I would like to think that if you can sail in it, then Savonius will not be optimal solution. Savonius is good only at low winds and when wind direction changes a lot, that is where it is strong, but certainly it is inefficient and that starts to matter when there is more wind which could be harvested much better with some 2 or 3 blade rotor type.

Those huge industrial wind turbines have savonius kind of rotors at top of them, those make emergency power and who knows what else, but that is where those are good, also if one needs fan for ventilation there savonius and other similar ones are good, every design has it's place and most of bad press comes when wrong product is used to wrong job.

As for Savonius being cutting edge, well, it was invented at 1922 by one Finnish guy, similar kind of things have been sketched and tested as early as 1616 according to Wiki page.

Anyway that has not much use to you, just thing that are nice to know.

This might be useful for you, mostly one graph at realtively early on document, it shows efficiency curves of different wind turbines, so you can see how different wind strength are where different designs do work, choice between 2 and 3 blade design should be easier with that, imo.
http://www.2004ewec.info/files/23_14...ucmenet_01.pdf