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craft
Newbie
Joined: 03/05/2008
Location: South AfricaPosts: 3 |
| Posted: 05:32pm 02 May 2008 |
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Howzit guys
Hoping I can find some help here.
I have the pleasure of living in South Africa - which was great and all, until our national power provider decided to introduce "load shedding" ... "load shedding" basically means ... "you're gonna have to deal with daily roaming black-outs, both commercial and residential, for the rest of your lives". Now, black-outs at work are one thing - but after sitting in traffic for two hours and arriving at your house only to find that you can't get your car in the garage, cook dinner, watch TV or even have a cup of tea is starting to grow tiresome.
That being said - I happen to live in what has to be THE SINGLE MOST windy part of south africa - we have consistent 40 km/h SE winds - for 6 months of the year - following by slightly less consistent - 60 km/h NW winds for the other 6 months – so obviously, a little wind power sprung to mind.
Basically, what I’d like to achieve is a small scale solution to the roaming blackouts – ideally, to have a small windmill running on my roof (there is a great position for it) aimed at generating and storing enough power to help us cope with the blackouts when they click in. The blackouts last for 4 hours at a time – so MAX, I’d be looking at storing and or generating enough power to run a small-ish suburban house for 6 hours.
Also, if it isn’t already completely obvious, I know NOTHING about windmills … other than that they go round … and that’s about all – to make it worse, I know even less about electricity and generators.
Right, diving straight in.
I’m guessing this will be a 2 part project:
Firstly establishing what kind of a windmill I’ll need to get going to power the house directly (if we’re loadshedding and the wind’s blowing then I want power – super)
Secondly, storing power for later use
So, to start – bare bones and as simple as it can be – some questions
1. How much power would I be looking to generate in order to run a small (3 bedroom house) for 6 hours? (This could be a stupid question to be asking on this forum?)
2. How much of a beast does my windmill need to be? Can I get away with a piddley one?
3. Whats going to be the most efficient manner for me to generate power (what should I use given my needs? – the Switched DC motor thingies?)
4. What should I use to store generated power?
5. How would I go about feeding the power I’m wanting to generate back my houses grid (if the answer is “get an electrician” then so be it)
If anyone has the time to point me in the right direction that would be great!
Cheers
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dwyer
Guru
Joined: 19/09/2005
Location: AustraliaPosts: 574 |
| Posted: 10:59pm 02 May 2008 |
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Hi craft
welcome aboard Best way for you to start with is to buy set of deep cylce Batteries with power inverter with batteries changer built together and plug in main power in case the power go off then you able to run you own power untill main power come back and batteries charger switch on automatically to top up the batteries l think that easier way to go, 
dwyer |
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GWatPE
Senior Member
Joined: 01/09/2006
Location: AustraliaPosts: 2127 |
| Posted: 11:26pm 02 May 2008 |
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Hi craft,
I would not initially try and run the whole house.
I would start off by measuring the power required by all of the domestic plug in essential appliances. You have mentioned some of them.
You will need an inverter of sufficient size to run all of these appliances together. Do not include heaters or cookers or water heating or air conditioners.
If you do not want to modify the house wiring then some problems with cords will exist.
A changeover from grid to inverter will be required, like what happens with a computer UPS, so you do not back feed to the grid. The battery reserve has to be of sufficient capacity to supply the load without exceeding the daily cycle and discharge ratings. You will need a good battery recharging system to maintain the battery.
I would start with a computer UPS with some cords to the most essential plug in components. The battery capacity will need to be icreased though. A windmill generator can be added, and solar panels to supplement the battery recharging.
There may be a commercial market for a successful solution. .. .. Gordon.
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CanTinker2
Newbie
Joined: 21/01/2008
Location: CanadaPosts: 14 |
| Posted: 11:43pm 02 May 2008 |
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Hi Craft
I have doen some calculations for a solar/wind hybrid system to supply a house that would be good enough for my wife (I figured 3/4 of my current electric bill). And came up with a figure of approx $80,000 USD if I did all the work myself (It helps to be an electrician).This seems reasonable to me and eaasily justifiable if where you are located there is not electricity nearby. If electricity is nearby at say $10 kW then payback is over 40 to 70 years.
You need to start by deciding how much power you are after. It is relativly inexpensive to supply a TV, some elctronics and compact florecent lights. However if you are talking about any electric heat (hair dryer), motors (garage doors etc.) or somthing silly like air conditioning, well you are talking about a substantial system and lots and lots of batteries. The other problem is an automatic device disconnect your house from the grid during the outages $$$$ and expertise is required. This is a fun hobby if you get into it and if you stay small it can be cost effective.
John
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craft
Newbie
Joined: 03/05/2008
Location: South AfricaPosts: 3 |
| Posted: 05:40pm 03 May 2008 |
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howzit guys!
thats really awesome info - thanks for your responses!
$80,000 USD is a figure that makes me soil myself a little tho - no lies!
So - based on everyone's feedback I'm going to refine my starting criteria a little
dwyer - thats a nice alternative! thank you! what are deep cylce Batteries (again I say - I know NOTHING of this world) - are they expensive? I'm gonna try and stay away from using our power supply to charge the batteries tho (our power provider has upped their rates by 56% this month to try and cope with their rolling blackout stuff up - 'yay' for 3rd world countries) - but its certainly an option!
GWatPE - "There may be a commercial market for a successful solution" - that is very much my end goal (aimed at the south african market) - as we've been told that we'll be having rolling blackouts until 2015 ... can I get another 'yay'!
Okay - so based on all of your feedback I need to decide what it is that I'm going to be running once the power has been turned off.
Ideally I'd like to be able to run the following:
1. Stove (these blackouts happen during the most insane hours - some suburbs have it from 6:00pm - 10:00pm twice a week - how they expect us to cook I dont know? On that note, here's a funny one, our minister of energy has receintly stated that the solution to our power crisis is that we should be watching less TV and going to bed earlier.
IQ ... of a brick
anway .. so yes - Ideally:
1. Stove (for about an hour of running time)
2. Fridge
3. One or two lights
4. The TV
and that would be it really
I have to say that I'm not keen for a hybrid solution as I'd like to try and compile the very simplist unit possible (ie. 1 x windmill  )
To summerize, would a potential solution be to have a bank of deep cylce batteries (or UPS units? which would be better?) being constantly charged by a small windmill?
Thanks again guys! |
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GWatPE
Senior Member
Joined: 01/09/2006
Location: AustraliaPosts: 2127 |
| Posted: 12:21am 04 May 2008 |
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Hi craft,
forget cooking, get a gas camping cooker. The fridge will not lose too much cooling in the time it is OFF, unless you have the door open admiring what is inside it.
Lights and TV is doable with battery and inverter. I would still use grid recharging as these components would be lowish consumption, unless you have a 50" plasma TV. I would add solar and possibly wind recharging of the battery IF the power cost to run these components became a problem.
You will still presumably have the cost of power for the other 18 hours of the day.
What price per unit do you pay for power?
I run TV, lights, computer from an inverter for approx 2-4 hours per evening. This uses approx 0.8-1.5kWhr of power to recharge my battery bank. I have solar and wind and grid recharging of my 24V battery system. My surplus power I Export back to the grid. My system is quite unique and I have had TV and Newspaper reviews on what I have done.
From your description you will require a supply and install solution. Obviously this would need to be done by a local company. 7 years is quite some time. Unless you can do a lot of the work yourself, RE systems cost a lot. I would start small with minimal outlay and house modification. If after 6-12 months it isn't working you could consider a complete longer term solution. Windmills in a suburban location can impact on the neighbours.
PS a deep cycle battery is one where the depth of discharge per cycle has a lower effect on the battery service lifetime. .. .. Gordon.
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grub
Senior Member
Joined: 27/11/2007
Location: AustraliaPosts: 169 |
| Posted: 12:32am 04 May 2008 |
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You could also go for a motor power generator for temporary backup. There are many alternative fuels one could look into to power it. For instance I came across the plans for a wood gas producer (same idea as the charcoal gas producers that one saw on cars during WW2 but uses wood chips). There is also steam engines, and solar steam engines. Old fashioned wood stoves, candles for lights, even methane gas from stewage. Some would be quicker to setup and others will eventually be shafted by "Carbon Tax" and hysterical greenies.
Plenty of ideas to choose from. |
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Bolty
Regular Member
Joined: 03/04/2008
Location: AustraliaPosts: 81 |
| Posted: 12:41am 04 May 2008 |
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Hi Craft!
I am also a newbie to Wind power, but I do have a background in Electronics and Physics.
You are in an interesting situation, modified considerably by the fact that you do get power for at least 18 hours per day! This means that given the availability of cheap power from the grid, it is probably better to look at storage for the period when the grid is down. The cost of installing a wind turbine that gives you automatic independence from the grid, would cost considerably more than other approaches.
Gordon has made the excellent suggestions of using UPS for some of your solutions. Looking specifically at each of your needs.
Stove
Trying to run a stove via stored electrical energy requires huge amounts of energy which equates to large capacity batteries and therefore large costs, both initial capital and renewal. Your easiest solution for cooking would probably to shift your timing. If this is not possible then use a gas stove. (LPG bottles if mains gas not available) Clearly gas is not a good enviromental solution, especially since you have large wind resources! However you cannot use a grid connect inverter system for this solution, as by design requirements, grid connect inverters MUST shut down whenever the grid supply is off! You could use a wind system connected to a very large bank of batteries, and then to a 240 volt inverter. This inverter could not be grid connected, but would require exstensive rewiring of your house. It would also require significant control circuitry or switching to allow the changeover from operating from the grid, to operating form the battery inverter system. The battery capacity needed for 1 hour of cooking would be enormous, especially if the wind was not blowing. As a guide most stoves are in the range of 4Kw. (You could determine your power needs by consulting a label on your stove) The F&P generators on this site generate much less than this. I think that Gordon's has generated an absolute maximum, only once of .5 kw (I assume in storm conditions before furling) As for battery reserves for 4kw for one hour, this represents a significant battery bank!
Fridge
It is not going to be a problem for the fridge to be off for 6 hours. During the off time, if the fridge were to be opened only infrequently, you would be surprised how little the temperature would rise. This is especially true in the freezer section. Annually, in the heat of summer,I go on a fishing trip, taking a large domestic freezer in my boat on a car trailer. On my return home with lots of fish, the freezer is disconnected from power for around 12 hours in the boat in full sun light, and often 40 degrees Celcius. The contents do not get anywhere near thawing despite most adverse conditions. I would imagine that you can work around a 6 hour power loss for your fridge.
One or two lights
If these are low energy lights, you are talking no more than 50 watts. This is nothing for a small battery system. To put this power into context, a typical car with headlights left on would consume around 150 watts, or if only parklights, around 40 watts. Even a small car with a small battery should be able to run parklights for at least 12 hours. My solution for this would not involve a wind system or a UPS, but I would purchase 2 exit lights that are used in public places. These are kind of a UPS built into a light, so that they will always work even when there is no power. I have one of these that was from a public hall. I have it installed in the lounge, so that whenever the power goes off, it automatically comes on instantly! When I got it it was about 10 years old, and all I needed to do was to replace the battery. I also used a solvent to remove the green exit lettering.
The TV
This is hard to estimate as it depends on your TV set size and type. If it is a large Plasma, you may need around 300 watts or more. If it is a small LCD TV you could reduce this power down to around the same power as your lighting. Even less would be a laptop computer with an attached TV tuner, but you would only get about 2 hours TV from the batteries. If you want to use your existing TV, you would need quite a large UPS to get 6 hours. As a simple guide, if your TV set is 200 watts, and you want to watch TV without power for 6 hours, you would need to have 1200 watt hours of storage (1.2kwhours) This would be requiring a large battery inside the UPS
As an example of a higher power UPS look at:
http://www.jaycar.com.au/productView.asp?ID=MP5206&CATID=&ke ywords=ups&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Key word2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
Whilst this would provide sufficient power for any TV, it does not have the capacity to last 6 hours. For the example above of 200 watts, the UPS has a capacity of 12 volts at 9 amps X2. So this is around 200 watt hours. So the Tv would only run for around an hour!
Garage door.
Depending on the size of your garage door (you really need to know the power needs of your door mechanism), you would be best to fit a totally independent, computer style of uninterrupted power supply to this (UPS). Gordon has also made this suggestion! Depending on power requirements for the door, this could be quite small and cheap. It would plug into the existing power point, and the door would plug into it, deriving its power from an internal battery and inverter. The battery is constantly being charged when power is available. This is a very simple solution that does not require an electrician, as it is just a matter of plugging in the device. Also the capacity needs of the UPS are small, as the door does not consume much power at all, except when opening or closing. Even this is relatively small, unless it is a huge door. Most garage doors are carefully balanced, and do not need much power!
If the above work-arounds do not suit your lifestyle etc. and you have a large budget, you could would need to consult a wind energy professional who could tailor your system for you!
Hope that this helps your understanding!
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AMUN-RA
Senior Member
Joined: 10/03/2007
Location: AustraliaPosts: 144 |
| Posted: 02:51am 04 May 2008 |
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http://ozefridge.com.au/default.htm I have one of these and they are great uses not much power and has long hold over times when power is out runs on just about any voltage you can feed it and is easy to set up . he also ships to anywhere in the world ,can be fitted to any old cabinet or build your own,worth a look anyway
Mick
Every day the sun shines
& gravity sucks= free energy. |
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davef
Guru
Joined: 14/05/2006
Location: New ZealandPosts: 499 |
| Posted: 11:05am 04 May 2008 |
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. . . – ideally, to have a small windmill running on my roof (there is a great position for it) . . .
Just in case you proceed with a windmill I'd suggest you do some investigation on roof mounted windmills. I have seen commercial VAWT installations on the www mounted on the roof, but I think you would find that mounting a HAWT on the roof would turn out to be a bad solution.
I'd go with gas for cooking and run the freezer and fridge off the batteries.
Good luck |
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Bolty
Regular Member
Joined: 03/04/2008
Location: AustraliaPosts: 81 |
| Posted: 03:52pm 04 May 2008 |
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Hey Gordon!
Just came back to check any other answers for "craft". We must have both seen his questions this morning at a similar time, as your response was not there when I wrote mine. Mine took quite a while to compose, and I wrote it in Notepad then pasted it into the un-refreshed "Post Reply" section. Had I refreshed the thread I would have seen your post. Hence the overlap and parallel responses from you and I. If I had refreshed the thread and seen yours, I would have then substantially modified my posting.
Just wanted to clear that up so that you did not form any incorrect ideas about my posting appearing after yours. The whole aim of all of this is to help others! Whilst you have incredibly more experience than me, I felt that I could offer some suggestions that would hopefully help "craft"!
Cheers!
Bolty |
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GWatPE
Senior Member
Joined: 01/09/2006
Location: AustraliaPosts: 2127 |
| Posted: 10:11pm 04 May 2008 |
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Hi Bolty,
This has happened to me as well, no biggy. .. .. Gordon.
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craft
Newbie
Joined: 03/05/2008
Location: South AfricaPosts: 3 |
| Posted: 08:04am 05 May 2008 |
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you guys have been a phenomenal help!!
thank you so much for the time you've put into your suggestions! They have given me an awesome platform to start from!
I'm going to mull through all of these new ideas to try and see what would work best in our situation - also going to try and figure out the correct amount of power I'm going to need to run the TV's, computer etc (the TV is a 37" LCD? are those quite heavy on power?)
Thanks again guys! will report back with an update shortly!
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