Navitron Renewable Energy and Sustainability Forum

WIND TURBINES => Wind Turbines and associated systems => Topic started by: welly on July 23, 2006, 05:11:31 PM



Title: 24v or 36v turbine?
Post by: welly on July 23, 2006, 05:11:31 PM
Hi,

I'm considering buying a small turbine system to power a home office (probably 500w), and although I've just about grasped the principles, I'm a little unsure of the nitty gritty!

I note from the FAQ that it is possible to use a 36v turbine in a 24v setup to give greater power at lower wind speeds, although with a lower maximum output.

With this in mind, and since the 500w is now available in both 36v and 24v, I'm not sure which option would be most suitable - a 36v turbine with 24v bank, controller, inverter, or the 24v turbine.

Is it just a case of average wind speed that I should be looking at when I decide, or is there more to it?

I also note that the 24v version is more expensive, and don't want to spend the extra money unnecessarily.

Can anyone advise?

Many thanks

Welly


Title: Re: 24v or 36v turbine?
Post by: Ian on July 24, 2006, 11:03:32 PM
Like so many things in RE there are no fixed standards and industry test methods so although a question question like this SHOULD be easy to answer it is more of an art than a science.

I think you have hit the nail on the head though - your primary determinant should be average wind speed. If you are getting average wind speeds approaching the RATED wind speed of your turbine, then go for a 24 volts turbine. If the average wind speed is significantly lower than the reated wind speed of your turbine, then you should start to think about a 36 volt model.

As you suggest, the higher voltage turbines have the potential to eak out a little more power in very light winds than the lower voltage models - but lets be clear here - the difference is modest as, at low wind speeds, there is only marginal power to be had anyway.

Average wind speed is notional - it does not actually exist. Sometimes there is zero wind and sometimes the wind is blowing MORE than the rated speed of your turbine. Think about what happens then and make sure that you do not overcharge your battery sets as these are the most fragile and most expensive components in your system and need to be protected from abuse.

On balance then, I would go for a 24 volt turbine to service a 24 volt battery set unless you really are in a very low wind situation (and then you should be questioning your use of wind power at all !).

I hope this helps.

Regards,
Ian


Title: Re: 24v or 36v turbine?
Post by: Ivan on July 30, 2006, 01:52:44 AM
Yes, 24v is the best option if you are planning to use 24v battery.

Consider a wind turbine like a car engine. The voltage is like the gearing. If the gearing is designed for 36v and you use it with 24v, then it is like trying to drive up steep hills in 5th gear. If you change down a gear (ie use a 24v turbine to drive 24v batter rather than using a 36v turbine to charge 24v battery), you can usually go up the hill faster.

Ivan


Title: Re: 24v or 36v turbine?
Post by: welly on August 04, 2006, 08:49:48 PM
Thanks chaps!

Cheers

Welly