Help needed for wind turbine motor 15kw

Rokz

Hi  i am hoping to get power to my  weekend retreat.Local electricity company want a lot of money to re connect.Hence looking for advice on a new motor i could purchase at a good price €250 here in Ireland.Hoping to find out will this motor be suitable...any help would be appreciated.

BB.

What do you want a 20 HP 3 phase 400 VAC (minimum) motor for?

For solar--About the only use is for water pumping (or similar load) that accepts variable RPM/Day Time (sunny weather) operation only (like irrigation). Mate that with a VFD based solar inverter/controller (variable frequency drive--It varies the frequency/therefore pump RPM based on loads and available solar power).

Not a simple project, but doable.

If you want/need to pump a lot of water for a small community, you can add batteries and VFD.

While it is possible to use an induction motor as a genset--It is not really practical--Basically you have to supply AC power to it (get it turning up to speed), then try to drive it faster than the RPM (based on frequency you feed it). It will then try to feed electricity "backwards" through the AC inverter and charge the battery bank. You would need to have high/sustained winds, and probably a variable pitch set of blades (like large wind turbine synchronous AC machines) to keep constant RPM but vary the torque based on wind.

If you are really into building your own wind turbine, here are some links (do not buy anything until you have a paper design--Rarely will buying stuff before you have workable plans result in any usable hardware):

Wind Power Links
www.otherpower.com (good forum for DIY Wind Power)
Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
Scoraig Wind "Recipe Book" for DYI Turbines (from Chris Olson... From his 4/11/2013 post)
www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)
Small windpower a scam ? Survey says SO
Truth About Skystream & SWWP
Windmax HY-2000 2kW Wind Turbine

More or less, plan on a minimum of a 20 meter tall tower and 10 meters above an nearby obstructions (houses/trees/buildings within 250 meters up wind)... And I would suggest that you place the tower in an area where if it (or the turbine/blades) falls, it will not hurt anyone.

Do It Yourself wind turbines are one of the projects where you can probably build a better product than you can purchase. The turbines, themselves, are relatively inexpensive. It is the tower, concrete, lift truck/crane, wiring, and electronics that cost a lot of money (and your time).

Normally, I would suggest a solar power+charge controller+battery+inverter system... But, if your sun is like this--Solar is difficult to justify:
http://www.solarelectricityhandbook.com/solar-irradiance.html

Dublin
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 37° angle from vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
1.08	1.79	2.48	3.42	3.91	3.76
Jul	Aug	Sep	Oct	Nov	Dec
3.70	3.42	2.93	2.06	1.42	0.94

Before you can plan/design/build any power system--You should really have a handle on the power/energy you need. More or less, a good place to start:

• 500 WH per day (30 days * 500 WH = 15,000 WH per month = 15 kWH per month) -- Weekend cabin LED lights, radio, cell phone charger, RV water pump.
• 1,000 WH per day (30 kWH per month) -- Add a laptop computer/LED TV.
• 3,300 WH per day (100 kWH per month) -- About the minimum power for a "normal electrical existence". Add full size refrigerator, deep well pump, washing machine, more power for kids/guests.
• 10-20 kWH per day (300-600 kWH per month) -- Typical grid connected home (usually natural gas for heating/hot water/cooking)
• 30-100 kWH per day (900-3,000 kWH per month) -- Electric stove, electric hot water, electric heating, Air Conditioning...
  

The first two systems are small/practical off grid power systems (usually solar) that work well for cabin (one step from camping) use.

The third system--About the largest I would suggest for a do it yourself first time solar power system (without professional/knowledgeable help). And you are spending something like $10-$20,000 or so (SWAG).

For you, say a 1,000 WH per day system is OK. And you can use solar for March through October... The math would look like:

• 1,000 WH per day * 1/0.85 AC inverter eff * 1/12 volt battery bank * 2 days of storage * 1/0.50 max battery discharge for longer life = 392 AH @ 12 volt battery bank

Or 2x 6 volt @ 200 AH golf cart batteries in series times 2 parallel strings (4 batteries total) for a 12 volt @ 400 AH system.

Use a small 300 Watt True Sine Wave inverter (230 VAC 50 Hz available).

For solar, assume 2.09 hours of average sun per day:

• 1,000 WH per day * 1/0.52 off grid system eff * 1/2.06 hours of sun per day = 934 Watt solar array (Octoberbreak even month)
  

And get a small/efficient genset like a Honda eu20i (petrol) or, if you can find, a small diesel (too large of genset will waste fuel for battery charging/running small winter loads). And a 40 amp @ 12 volt AC to DC battery charger.

BB.

I am not a fan of small wind (or big wind, for that matter). It can make sense if you live in a misserably windy rural location with few trees/buildings nearby.

And off grid power only makes sense if your power needs are small... Very roughly, it costs ~$1 to $2+ (USD) per kWH for an off grid solar power system (not much sun and seasonal/weekend use push price up towards the high higher costs).

You really need to do some math--Figure out your power needs. Look at how much it costs to build (and maintain--Batteries need replacements every 3-5 years for "cheap" batteries; electronics need to be replaced every 10+ years; winter use needs genset and fuel costs are high in Ireland) an off grid power system.

In the US, connection fees are not cheap for rural power (can easily be $10,000's of USD for a few poles and wiring)... And now we are getting power plans (US and Canada) where the $/kWH price is not bad, but the monthly connection fee went from $5 per month to $20 -> $50 per month (USD).

Energy usage is a highly personal set of choices--Hopefully, we can give you information you can use to figure out what would be best for you.

-Bill