Wind power

[Boots]

I wonder if those "in the know" might look over this for me?

Wind power is rarely mentioned here...in many rural areas, solar is still just a word that refers to 'greenies' and weird ways. A mate of mine has a great system, that he has tried to explain to me, and even offered to show me how to set up if I found the panels - but I am now thinking *wind*....

While windmills are still used to pump water, they are considered 'old fashioned'... so it has been very interesting poking around and considering wind power as a 'modern and earth friendly advance'.

I would love to tell my inadequate electricity provider to take a running jump. We have constant blackouts and as anyone living in rural Australia knows our electricity *service* (I use that word very loosely) is appalling. When I consider the amount I hand over to them, so they can treat me as a second rate citizen, and ensure I live like one for at least two days of every month, the thought of investing in something like this is very, very appealing and both earth and back pocket friendly.
http://www.flowtrack.com.au/index.html

Is there anyone here who can advise me on this?

How many of these would be needed to run a home? (Dunno what 5kW means... )

How do you convert 3 phase power (and do you need to?)

How much work is needed to run and maintain them? Windmills just seem to look after themselves... but does this need to be turned on and off or something (don't really get the whole running bit...)

Clearly not an electrically minded individual - Boots!

[Andy Hamilton]

Nev's your man on this one. He was saying that, at least in Sydney, you need some kind of permit from the council to have a domestic turbine. Not cheap either.

[Wombat]

Sorry Boots, I need to think about this a bit and it's almost 5:00am (Jet lag, don't you love it). In the words of Fatty Vaughtin - "I'll get back to you".

Nev

[Millymollymandy]

Oh oh oh - I'm so excited - I can answer a question here!!!

I know about how many kW you need because it's something we choose as part of our leccy tariff in France and we pay more annual charges the more kW you have.

We are on 12kW but that's because we are on tri-phase. Probably would only need 9kW otherwise. (Don't ask me to explain the difference ).

9kW on single phase should be fine for a 'normal' home that runs lots of electrical things like washing machine, tumble dryer, dishwasher, fridges, freezers etc, but wouldn't be enough if you are using electric central heating. However for the occasional electric heater it should be OK, but beware of fan heaters because some of 'em are 3kW on max, alone!!!

[Wombat]

M3 Boots is in QLD so I don't think that central heating is an issue!

Boots,

The wind alternator generates 3 phase AC current which is then rectified to either 100v or 48v DC, which is storable in batteries (AC isn't). you would need a battery bank to store the power generated and the size of the battery bank would be determined by the size of your loads (appliances, lights etc.) The number of kw it generates is a measure of how fast it will re-charge your batteries when it is turning, the more kilowatts (kw) the faster it recharges.

There doesn't seem to be any price, but it looks EXPENSIVE to me, and the generator itself is only part of the equation - batteries aren't cheap!

The cheapest locally available (in NSW anyway) wind generator is from Oatley electronics, they used to be $700 for a 250w generator but are on special at the moment for only $450. See the link below.

http://www.oatleyelectronics.com/

The first job is to add up the wattage on all the loads you want to run, the following link will give you an idea -

http://www.kimcoweb.com/calculator/homewattage.html

The "Surge" wattage is there because electric motors will take 4-5 times the current they consume while running to start. The question is then do you want to buy an inverter to conver the 12vd to 240vac and run your system as is or convert your set-up to 12vdc. There are points for each - a big inverter will cost lots and chew up power if connected, even when not "on".

Let me know if you have any questions (lots probably) but this will give you something to think about. PM me your phone no if you want to talk about it.

Lots of luck!

Nev

[Muddypause]

Nev knows more about this than me, but here's my penny's worth anyway:

If you want something that will work off-grid, you will almost certainly need some means of storing the energy. This is usualy in storage batteries, typically lead-acid ones, similar to the type that you find in cars. As Nev says, these are expensive. Also, any form of storage, as well as the use of transformers, inverters and rectifiers, will build in losses to the system - you will not get as much out as the generator puts in.

A more efficient way of using the power may be to use it to suppliment your on-grid connection, though this doesn't really solve your problem. However, it means that any electricity that you generate will reduce the amount you use from the utility company. With the proper connection to your domestic supply, your generator will slow down the electricity meter; if you generate more than you are using, it will feed the excess into the grid, and your meter will actually turn backwards, in effect banking your surplus energy for later use. This is a much more efficient form of 'storage', but does depend upon a grid connection.

I'd suggest that wind power of this nature would be best used on stuff that you can run on a separate circuit - low voltage lighting is the obvious example. Many electronic appliances like radios, CD players, computers, etc., have step-down transformers in them anyway, and so may be adaptable for use on a low voltage system too. Used like this, a storage battery system may work well, but you need to be aware that the lower the voltage, the thicker the cable you need in order to avoid loss due to resistance (I suspect Google will turn up an equation to calculate cable dia. over voltage); try and plan the system to avoid, long runs, particularly as thick copper cable can be expensive.

When doing your calculations, you need to allow for the fact that the wind doesn't blow all the time. Most equations that I see assume that the average output of a generator will be around 30% of its maximum.

[Millymollymandy]

Hey, Queensland outback can be ruddy cold at night in winter - I know, I was camping there in a sleeping bag guaranteed to keep you warm down to +10C - except it was Zero C!!

I think I was also probably talking rubbish above and I think I should have substituted kVA for kW except in the context of the fan heater. I would have to look on an electric bill to check. Ah well, we dumb blondes have to try sometimes.

[Boots]

Hi Nev,
Have just gone back and forth between those sites, trying to absorb it. At face value it looks like I could very easily redirect my present power costs into this unit and be recouping the benefits within a year.

The estimator guide suggested I needed a mini power plant but I was being a bit enthusiastic, maybe?...putting everything down, as nothing is used all the time and simultaenously? Figured it was better to overestimate than underestimate?

First question... The Oatley unit doesn't list a KW rate. Does 200w compute to something for the more electrically minded?

Second question... Can I set these up side by side to produce the necessary power? If so, how many would you recommend to run a small home? If M3 is right, then two would do it?

Q3...How many batteries are we talking? My mate runs 6 truck batteries with his solar backup unit...How long would they last and how many would be needed for continous use?

mmm. Ok..just saw Muddys response.

Q4... You mean I direct power into the existing grid? Bloody ell! Just the thought brings visions of fireworks and me and my goats floating in space somewhere. How do I do that Muddy? Just buy the gear and ring an electrician? Will an electrician do that?

M3...ummmm, psssst I often run an airconditioner at night!!! *naughty, naughty, slaps wrist*

[Muddypause]

Q4...

A: You need a magic black box to make the connection (and possibly the agreement of your utility company, too), but in effect, yes, you direct your unused power into the grid. Obviously, you need to be producing 240V.

Hugh Piggott is a windmill builder in Scotland, and has a site with some useful links on it, one of which is to a windmiller in Queensland

[Wombat]

G'Day Boots,

Q1 - 200w = 0.2kw

Q2 - Yes you can run them side by side, but how many? that is much harder to answer....... Once you work out your power draw you need to get some data from the bureau of meteorology about average wind speeds as close to your site as possible. Try asking at your local post office as they quite often record such things for the BOM.

It really comes back to lifestyle, you need to work out what level of comfort is acceptable. For example, the aircon would consume large amounts of power, couple the generating capacity with the size of the inverter needed and the price would pay off the national debt. But an evaporative cooler only uses around 1/10 the power (roughtly) and if you live away from the coast and the heat is dry..........

It comes back to beingaware of what choices we make. Have you had a look through my 12v power article on the site?

Q3 - How many batteries you need also will hinge pretty much on what you want to run. The info from the BOM will also help here, because if you are using wind only you will need to allow enough storage for the average (or maximum) windless period.

Q4 - it would be very remiss of me to not state at this point that ANY and ALL wiring for 240v form the mains or an inverter must be carried out by a licensed electrician! I think you would also need to talk to your electricity supplier and see if the are agreeable. Generally they put in a meter that goes both ways, this means you get grid power when you need it and feed electricity back into the grid when you are producing excess.

Second hand batteries do work, I used some old forklift batteries for years, (again, have a look at the article) but they are also prone to fail without notice! Deep cycle is best - but cost you!

By running your system direct into the grid you save money and carbon dioxide, but are still vulnerable if the power grid goes down, so again, it depends on what you want.

In summary - decide whether you want cost reductions or autonomy, deide on what electrical appliances you can't live without, get some info form the BOM to assess your site's generation potential. The feeding back into the grid option is less hassle and cheaper, but you are still exposed during a blackout!

Hope this helps!

Nev

PS, just saw Stew's comments, and as usual I agree entirely.

[Millymollymandy]

Oh oh oh - I'm so excited - I can answer a question here!!!

I know about how many kW you need because it's something we choose as part of our leccy tariff in France and we pay more annual charges the more kW you have.

We are on 12kW but that's because we are on tri-phase. Probably would only need 9kW otherwise. (Don't ask me to explain the difference ).

9kW on single phase should be fine for a 'normal' home that runs lots of electrical things like washing machine, tumble dryer, dishwasher, fridges, freezers etc, but wouldn't be enough if you are using electric central heating. However for the occasional electric heater it should be OK, but beware of fan heaters because some of 'em are 3kW on max, alone!!!

I checked and our supply is measured in kVA, not kW. I don't know what the difference is though!

[Wombat]

I'm not a sparkie, but I think the differences are technical and as far as us lay persons go the terms are used interchangeably..........

Nev

[Muddypause]

I was hoping you'd know, Nev, 'cos it puzzles me too.

Since a Watt is the product of multiplying a Volt by an Amp, you'd think that a kVA was the same as a kW.

It seems to me that kW is used when refering to an input - eg a 1kW heater is a description of its power it consumption; whereas, a kVA is applied to an output - eg a generator may have a rating in kVA.

Also, a bit of googling seems to imply that a kVA is only applicable to AC current, and that a kW is a kVA/0.8, which I don't understand. But another site said kVA/0.8 = 1 kWh (a kilowatt hour) - which I would have said was an incorrect mixup of units.

Wish I'd paid more attention at school.

[Wombat]

Confuses me too mate - I think the power factor of the generation equiment is involved too, so that if it is 1 then Kw = KVA, it it is less than one, which it usually is I thnk then that will be the multiplier.

QED

Nev