Micro wind turbines

bullit_dodger

why would a 48v cable be smaller than 12v?

It's a very good question that! So the "power" (energy) that travels over a wire is a factor of the voltage and the current. So as we have lower voltages, to get the same power we have to have higher current (amps). Unfortunately higher amps means that the cables get hotter due to the resistance on the wire. So when you have higher currents, you need to have thicker cables which won't heat as much and potentially melt.

Eg. to get 1Kw of power at 12v you would have to have a cable rated for (1000/12=83amps), but to get 1Kw of power at 48v you would need a cable rated for 20.8amps. The thickness of the cable determines the current it can take.

is there such a thing as a charge controller where I could wire multiple turbines into it?

Not sure, there might be some that take 2x inputs, but unlikely one that would take 5-6. If all the turbines were identical (DC output), you could have the multiple turbines going to a shared busbar and from there going to the controller as a single connection. There are potentially some dodgy things which could go wrong here though which I not sure I'd recommend. If say you had 4 turbines and one stopped (blade got stuck or something), then potentially the other turbines would be backfeeding the stuck turbine - it would destroy it. You could get around that with some diodes, but then we're getting into a much more complex scenario involving more electronics.

Honestly, I'd get in 1x smallish turbine with appropriate charge controller and dump load as a "test bed". You can probably get charge controller and dump resister for <€200. Set it up to heat say a 200L tank as a test. If this works out then you could have a runner for 1 bigger turbine. I'd reckon that 1 big turbine could be more cost effective than 6 smaller ones. Larger turbines also tend to have lower "startup" wind speeds, and generate more power at lower wind speeds than smaller ones.

Overall, you'll be better off with 1 large one. There are others here though who are more knowledgeable than me (some having done their own installations).

E.g Charge controller and dump load £167 stg.

ATTNIB 2000W 12V 24V 0~1000W Wind 0~1000W Solar MPPT Wind Solar Hybrid Charge Controller, With Dump Load Wind Turbine Generator Solar Charger, With LCD Display And Unloading Resistor : Amazon.co.uk: Business, Industry & Science

(Not suggesting you buy this one, but just giving you an example for price reasons)

Dtp1979

https://www.boards.ie/discussion/comment/120055805#Comment_120055805

This is the cable I bought for 12v 600watt turbine going to an immersion of the same rating. Would this be ok?

ill have a look at some larger turbines too. Any links to decent ones? Thanks for the help. I’m currently in the process of trying it on a smaller scale with the hot water cylinder before I start work on the giant buffer

bullit_dodger

So it's kind of hard to say that the cable is/isn't applicable for what you want to do as it depends a little on the voltage that you select for your system and the power that you are passing through it. it sounds complicated when you first start looking, but really you'll get it after awhile (trust me!)

Ampacity Charts - Cerrowire

The cable you have (above) of 10AWG (American Wire Guage) or 6mm^2 in "real money" :-)... if I look that up on the web page, I can see that that cable is listed as being capable of passing 30-40amp. Depends on the temperature, but its in about that kind of range of 30-40amps is the main thing.

So if you had a 12V (turbine) then you could have at most a 300-400watt turbine (as 12v multiplied by 30 amp = 360 watts) without heating the cable too much. If you were using a 24v system, then you could double that and have a ~700Watt turbine with that cable.

You can see the advantages of the higher volts here. Most people use 24v/48v as a result, as copper is expensive and thick fat cables for 12V are way more expensive than thinner ones for 24v or 48v. 48V is still low enough to be "safe", but 24v is good compromise.

Honestly, no idea of good large turbines. Definitely do your research here. Theres a lot of shisters out there, mostly chinese who claim rated power of (say) 2Kw and in reality when you run them you (might) get like 400w. One solid reputable large turbine will definetely be less complicated than many smaller ones and give you better value for money.

I think it's a great idea to do a "test bed". Firmly believe that you'll get this to work. The electrics seem complicated, but honestly you have enough people here to advise, and you have all the "harder" plumbing knowledge :-)

graememk

https://www.boards.ie/discussion/comment/120056126#Comment_120056126

Voltages for cables is generally irrelevant, as long as the insulation is rated for the voltage (a bit like pressure rating for pipes)

It all comes down to current (amperage)

Power is voltage x amps

So 600w at 12 v is 50 amps

600w at 48 v 12.5 amps.

For the 600 w you'd be wanting at least 10mm2 cable (there's online cable size calculators)

12 amps, would allow much smaller cables.

championc

It sounds like the best option is to link one to a grid-tied inverter, and then turn on your immersion when you like, albeit when the wind is whipping

Dtp1979

ok so that wire is too small. Feck. Live n learn. thanks for all the help so far

reboot

Small scale project as discussed elsewhere involved an outlay of €200 for a 100 watt turbine.

It's only about ten feet off the ground, producing 5 Amps into a 12v ev lipo battery system with bms balancing.

Maybe some think it's a pointless project, and maybe they're right.

bullit_dodger

https://www.boards.ie/discussion/comment/120058017#Comment_120058017

Nahh, not pointless at all, but unfortunately 100watts ain't going to cut it when you want to heat 2000L :-) Assuming zero losses, it would take a 100watt turbine 5 weeks running constantly at 100% efficiency to heat the tank once from 25C->60C

DTP that cable you have is fine, just not perhaps for 12V. It could be used in a 48V system no problem. Are you cemented into 12V for some reason?

Dtp1979

https://www.boards.ie/discussion/comment/120058151#Comment_120058151

Not cemented no. But I’ve installed a 12v immersion and bought a 12v turbine. These were bought so I could experiment on my hot water cylinder before I bought more for my buffer. I’ll just upgrade the cable then rethink what I’ll do with the buffer

Dtp1979

Why are the wires that leave my turbine so small? They’re like 1.5 square. The wire is only 6” long

graememk

https://www.boards.ie/discussion/comment/120058619#Comment_120058619

Wires leaving the inverter are 3 phase AC, vs 12v DC, there's 3x the current availability.

I dare say 600w is peak in a gale, so 100-200w is could be the normal load. Any load graphs supplied with it?

Dtp1979

https://www.boards.ie/discussion/comment/120058663#Comment_120058663

But mine says it’s a 12v DC turbine, not AC, which is why I’m wondering about the small size. I don’t expect to get 600 watt from it.

No graphs no

Nelbert

Is there any symbols or labels on each wire?

reboot

https://www.boards.ie/discussion/comment/120058151#Comment_120058151

Obviously I'm crossing threads and should have explained I'm not trying to heat water. I charge USB 5v devices,use Leds in home lighting and Christmas decorations, radio and TV, Pond pump, wireless rf txs ,power banks,charging car battery, and some useful things besides. I note very little interest seems to be in small scale,5amps more than enough for me,supplemented by 30 Watts pv panels. Some folk want,more ,bigger, costly, only have to observe the same across in the EV thread ,heavy cars that take hundreds of amps just to move them.Expensive chargers delivering 160 Amps,when a slow charge would preserve the lipo.

Do you fing the bullets you dodge come mostly from snipers.?

Dtp1979

Also, I’m struggling to find a charge controller over 40A. My turbine is 50A. Do I need a charge controller even if I’m not charging a battery? Is there no other device I can use that will divert power to the dump resistor?

championc

https://www.boards.ie/discussion/comment/120058782#Comment_120058782

How many wires are coming out of the slip-ring / bottom of the turbine ? I'm guessing 3 wires and not 2.

If it is indeed 3 wires, this would be AC 3-phases, which needs to be connected into a bridge rectifier or a Charge Controller which accepts 3-phase input. A Turbine Charge Controller would have the bridge rectifier incorporated, along with a brake in the case of high winds

Look up the eSmart3 Charge Controller

Dtp1979

https://www.boards.ie/discussion/comment/120058917#Comment_120058917

There’s only 2 wires. The cable i have looks like a standard 1.5 square flex about 6 inches long and definitely 2 core

championc

Make / brand / link ?

Dtp1979

https://www.boards.ie/discussion/comment/120059291#Comment_120059291

Here ya go

championc

Oh.

Don't expect much out of that.

While the wind pushes the cupped side on the left, it pushes against the domed side on the opposite side.

Probably nothing more than a bike dynamo below it, so the thin cables now make sense. Very happy to be proved wrong though.

Dtp1979

https://www.boards.ie/discussion/comment/120059520#Comment_120059520

No idea myself they just have good reviews

bullit_dodger

https://www.boards.ie/discussion/comment/120059663#Comment_120059663

That's the problem with residential wind turbines, the internet is LITTERED with positive reviews for wind turbines. Most (if not all) of them are utter pants. It might say 600w, but in reality I would say you will be lucky to get it peaking at 150w and for most of the time it will be in about the 50W range.

Unless your living right on the coast of Ireland, I'd say to "set expectations" that you won't get much. Like championc mentions above, I'd happy to be wrong on that, but sadly fear the worst. Some review of that turbine here...

(1153) Watch this before you buy a wind generator, My personal experience, and what to look for - YouTube

Don't disband the idea though. If you have a good wind source, you could get a working installation (but horizontal axis)

reboot

Agreed,cut in speed all important,otherwise is just turning around wearing out it's bearings.

Dtp1979

https://www.boards.ie/discussion/comment/120060035#Comment_120060035

Good video and it’s made me do a U turn. I think I’ll have a look a 2-3 IstaBreeze units.

Dtp1979

Had a look at the IstaBreeze unit i2000. Really like it. I’m thinking of getting g 2. I called them but the language barrier was very hard to overcome and alot of crossed wires.

basically they’re A/C. If I was to use AC immersions could I wire directly A/C to A/C?

mot am I better using DC immersions?

championc

A good YouTuber with the Ista Breeze units is "Toys for watts".

All of those "proper" turbines generate 3-phase AC, which you can either feed into a dedicated Wind Turbine Controller or else into a bridge rectifier into a charge controller, both methods generating DC power.

I've no idea as to whether you can work directly with 3-phase AC

Dtp1979

https://www.boards.ie/discussion/comment/120063674#Comment_120063674

If I go from 3 phase AC using a charge controller do I still need a battery?

graememk

Three phase AC from a turbine is usually recified into DC and then either to a battery or though an inverter to 240 ac

The ac voltage is still quite low 12-48v

Dtp1979

So can I skip the inverter and battery part and go from controller to immersion?

championc

https://www.boards.ie/discussion/comment/120063788#Comment_120063788

AFAIK, the DC from the rectifier / controller will be variable. Rather than a static voltage and variable current.

It would then be the controller which will create the fairly fixed DC voltage