Pc fan generators

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Martin Steele

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Hi my name is Martin Steele I live in the UK, like all of us at the moment we are all suffering from high energy prices.

So I am having a Solar system put in at the end of August.

Then I got to thinking about complimentary wind energy this would tie in with my solar system perfectly. We live in quite a windy county and the flat roof to the front of my premesis looks out over the valley below, and makes me feel quite dizzy when I get up there.

The only problem with this plan is my carbon caring councill,if I even dared to put a wind turbine up there they would be dancing all over my premesis, issuing me with court orders Warrents ect ect ect.

So never to be defeated I started searching around for alternative wind generation devices that might help to fill the need.

One of the ideas that I have come across is generation using old or new pc fans, my knowledge of electronics is rudimentary to say the least.

Is there anybody on this site that can offer some sound advice or another solution to this problem.

I dont have an awful.lot of money to throw at this so solutions need to be inivative.

Regards Martin Steele
 
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Welcome.
Generation with solar panels is preferable to windmills in urban areas and perhaps rural too.
Solar panels have never been cheaper, well, perhaps a couple of years ago they were. What kills any budget is the flies around the cake. Consulting, planning, designing, financing, interst on loans, inflated retailer profits for panels and inverter, batteries if you go that way, transporting, 'standard' inflated hardware, engineering, installers, electricians, insurance, permits, paperwork preparers... Everyone wants a piece of your wallet ending in a triple expense.

The more flies around the cake, the worst it gets. Try to do as much as possible yourself without adding more mouths to feed as ambulance, hospital, and that kind of expensive mouths asking to be filled by falling from the roof. be safely tied.

I put 5600W not financed on my roof myself, transported and full installed, wiring, very slowly as am an old fart. System is 2 years old now, will pay itself next june : 3 years. Feeding extra mouths can double or more the amortization time. Avoid !

The energy am generating is ~30KWh on a good day, ~10KWh on a bad one. My electric energy invoice is $0 monthly for the last 2 years; have delivered to the utility the same I have consumed from them. Does not apply everywhere, but study your figures and utility rules. Measure your wind speed and times or get data from a corresponding entity. Is anyone else generating from wind in your neighborhood ? !!!

PC fans are absurd to consider.
Do you know what power you want to generate ? What do you expect/want to run with solar energy ? What skills do you have ? And friends, relatives, expertises ? Ask your 'carbon caring council' that you do not need to make them richer, get guidance, not fines.

Suggestion: read all again, twice and slowly.
 
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Most pc fans are brushless DC motors. Now, I'm sure that if I say there is absolutely no way they can be used as generators, someone somewhere will post something about it.

So, let's just say that if, by some miracle, it is possible, the fan's blade area to mass ratio will be so small that it will take a hurricane to produce anything. 100 cubic feet per minute through a 4" or 5" circle is a l.o.t of air.

And, whatever is produced will almost certainly be less energy that it took to run the fan as a fan, which wasn't much.

ak
 
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First off, how much energy do you expect to generate? - PC fans (even ones that would work as generators) will only produce tiny amounts of power.

So assuming your electricity bill is £100 per month, would you consider it worthwhile by saving 10 pence (or less) per month) - a VERY rough guess at what one PC fan might generate.
 
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Hi I don't know your name but anyway the idea came from. here,



I have just paid £13,000 for a 12 kW battery and 3 kw of panels.

I would be interested in knowing what you paid for your system.

Some of the Chinese built stuff is eywateringly cheap but unfortunately I can not get any engineers within a mile of imported Chinese gear something to do with MCS certificates.

How did you go on with this problem.

Ps I would appreciate your take on the attached.


Regards Martin Steele
 
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Hi I don't know your name but anyway the idea came from. here,



I have just paid £13,000 for a 12 kW battery and 3 kw of panels.

I would be interested in knowing what you paid for your system.

Some of the Chinese built stuff is eywateringly cheap but unfortunately I can not get any engineers within a mile of imported Chinese gear something to do with MCS certificates.

How did you go on with this problem.

Ps I would appreciate your take on the attached.


Regards Martin Steele
 
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Martin Steele said:
Ps I would appreciate your take on the attached.
Click to expand...
Assuming 10 pence per month saving (as I guessed above), then 90 fans would save £9 per month, simple maths. I would expect a single windmill of similar size would generate considerably more power than those 90 little fans - most of the assemly is just wood, not fans.

You also have the problem of what to do with a low voltage, low current, power source - and how to integrate it in to your house.

I went to a house a few years back, on a street called 'Mill Lane' (or similar), to the left one of a pair of semi-detached houses. As can be deduced by the street name, there used to be a mill there - and the water feeding it came directly down the middle of these two houses.

So they got together and fitted a small turbine which gave 2000W 24 hours a day, 365.25 days a year, the mill was build there because the water was so reliable.

They shared the output, 1000W each, and if they weren't using 1000W the excess was dumped in to storage heaters in the bedrooms.
 
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Martin Steele said:
One of the ideas that I have come across is generation using old or new pc fans, my knowledge of electronics is rudimentary to say the least.
Click to expand...

To be blunt, a total waste of money and effort.

B&Q in the UK used to sell a DIY wind turbine, 1.9m diameter blades or somewhere near that?
The manufacturers claimed 1KW output with a 30mph wind.

B&Q discontinued them after users found they were getting around 10% ?? (from memory, possibly wrong) on average from them in the UK.

If my memory is correct, that's 100W from a roughly 6' diameter, purpose made blade.

Scale the area to 4.5" diameter for a typical 120mm PC case fan, that's roughly 1/250th the area so around 400mW average per fan, IF they can reach the same efficiency as a purpose made turbine, which is extremely unlikely, as the baffle they are mounted in will probably cause far more turbulence than around a simple open blade type.


References:

On your roof for £1,500, B&Q's windmill

They have a wingspan of almost 6ft, hum in the breeze and could be landing soon on a rooftop near you - whether you like it or not
www.thisismoney.co.uk

B&Q pulls wind turbines from shelves

Report says machines generate only a fraction of energy claimed by manufacturers
www.theguardian.com
 
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His math is off by a factor of 500% - not a good sign.

200 mA at 3.4 V is 0.68 W, not 3.4 W. Divided by 90, that is an average of 0.00755 W per fan.

To put this in context, a normal USB port can deliver 1 A at 5 V, or 5 W. To do this with an expanded version of his fan array design would take 662 fans.

ak
 
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Hi. I paid cash ~$3230 for 14 x 390Watt Q solar panels [2m x 1m each] + 6KW grid-tied inverter [Growatt]. New, not used; not financed, no installers, not transported, no 'consulting', not taxed, no electricians, no batteries, in 2021 :


These panels were $170 two years ago.



Remember above ? :
Externet said:
inflated retailer profits for panels and inverter, batteries if you go that way,
Click to expand...
You have been working for the vendor way more than for your solar system. And now you are after feeding engineers as you say above

Sadly, is the rip-off from everyone doubling or tripling prices pursuing the easy living.

My humble roof :
 
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A 30 mph wind is going to be very rare in a suburban area near a house. Offshore turbines are where they are to get more wind more of the time and they still have a capacity factor of 25 - 40%.

A 1.9 m diameter turbine at 30 mph has a theoretical maximum of 2.4 kW or so, and I would guess that 1 kW is quite possible, but I can also believe that it's quite possible to average less than 10% of that, especially as you only get 90 W as a theoretical maximum at 10 mph.
 
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The OP should do a total lifecycle analysis before starting. The power used for the solder, make the wire, drive to collect the various raw materials (even if the fans are free) will likely take much more power than that contraption on the YouTube video can produce in 10-years. Long before that time, the bearings in the fans will be rusted and seized.
 
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Start with something that will not eat your wallet and later multiply if satisfied. If it is "for a boat", likely has an inflated price. Perhaps an used one to try first ?

----> https://duckduckgo.com/?q=wind+generators+for+boats&t=ffab&iax=images&ia=images

If you already have :
Martin Steele said:
I have just paid £13,000 for a 12 kW battery and 3 kw of panels.
Click to expand...
Find a compatible windmill that can feed its energy into that battery.
What is your plan to supply your house using the energy stored in that D.C. battery ?
 
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