Wind power plant

What do you mean by 500 Watt lamps? If you want to use wind power you really want to be looking for the most efficient form of lighting first.

Gareth.

Well, I guess that the 10kW one could, with a bit to spare, assuming that it's going to be located on top of a mountain in Scotland ... :-)

Arfa

Its a bit more complicated than just hooking a generator up to a lamp and waiting for wind. Uunless you want unreliable variable brightness whenever mother nature feels like giving it to you.

Think of it this way. You want to operate a 6000W load for say 8 hours, thats 48kWh of energy you need to store and deliver on demand. So now you need a battery pack that can hold that much energy and a power converter to charge it and convert it back to whatever your lamps need (wise to use 12VDC lamps and avoid an inverter alltogether). If all you wanted was one hour of

12V lighting then that 6000W will need a 500Ah battery and for 8 hours you need 2000Ah of battery capacity. Thats probably what 2-4 car batteries to be safe (my guess).

Now you need to be able to charge that battery during the daytime before you turn the lamps on and any more wind you get at night can reduce that requirement by a fraction. a 5KW generator running at peak power (quite breezy) will charge that battery bank in 9.6 hours of continuous wind. a

10kW generator in half the time but requiring more wind force.

Derate that whole calculation by the reliability of your wind. or that fraction of the average day when enough wind is present to operate the windmill at peak power.

So it all depends on how long you want the lights on and how reliable the wind is at that location. If it is unreliable and you want 12 hours of light, you will need a 15kW generator for par. A bigger battery pack and a fair start with a full charge will extend lighting time for occasional windless days and nights but on average you need to replenish 110% of the power you deliver to the load with newly generated power (10% estimated for losses in conversion). A similar process is used to evaluate PV as well.

500W of incandescent or halogen lighting is inefficient, ballasted halide or fluorescent lighting (anything called high efficiency or HE) will put out as many lumens for less watts. When evaluating the best type of lamp consider the lumens par watt, bulb lifetime and compatibility of the bulb voltage with your system voltage. Some lighting has a turn on surge current rating you need to account for at some level of the design

It's a lot more than that. A typical deep cycle marine/RV battery is about

80Ah. Fortunately the battery only needs to have enough capacity to carry over during times when there isn't adequate wind.

Usage pattern also needs to be taken into consideration. HID lamps (of which metal halide is one) don't like to be power cycled. They take several minutes to warm up, and if shut off, need several minutes to cool down before they will restart.

If the site has utility power available, you can use that for times when the wind is not blowing, store a smaller amount dictated by the economics of said storage; and sell the excess to the utility once that storage capacity is filled. IOW, you don't have to have 100% storage capacity on-site. The utility is, in effect, your storage, since you are selling them power when you don't need it, and buying it back from them when you do.

At least you can do this in the US. I don't know if the UK has a similar program.

jak

"pipedown" wrote in news:%vsNj.1821$pS4.1264 @newssvr13.news.prodigy.net:

Unless the runs to the lamps are long, in which case IR losses would be much higher(or cable costs higher) at 12 V than 110 V.

--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an 
infinite set.

bz+spr@ch100-5.chem.lsu.edu   remove ch100-5 to avoid spam trap

Even short runs at those power levels would have unacceptable losses unless you used massive copper welding cable or something.

The orginal poster must have spammed the groups. Stop this thread, allthough its interesting. Lets see, the poster also used the group alt.obituaries I thought it was weird when the poster never came back, so I searched Google Groups.

greg