Wind and/or Solar Energy

po0k

I need to power a device (small PC*) using renewable energy.

I figure seeing as this is Ireland I'm best off using wind-energy, perhaps with solar power and/or a chargable battery as backup to smooth out the troughs of wind.

I'm at the initial stages of planning the overll project, and before I go sourcing components I'd like to have an idea of what sort of power requirements I can play with.
How hard would it be to get ~100W from a small wind-generator?
Prop diameter would be about 50cm.

I'd be on for designing and building it myself, but I've never done anything like this before.

The bit of googling I've done has turned up some interesting results, but mainly from Americans who's idea of "small-scale" is a 20' iron structure.

* I'd imagine total power consumption (cpu, chipsets, ram, antennae, CF Drive to be about 40W max).

mrhappy42

I looked into this as well at one stage. The big issue is the 'tower' and the dc2dc converter. However I would recommend that you use a laptop as it has a build in power source so all you need is to plug the 12 or 18 v directly into the laptop (after some smoothing) and let it handle to storage etc.

One company in Ireland and One in Scotland do small wind generators.

www.pet.ie I think is the web site.

emaherx

maplin sell small wind turbines and solar pannels as well as regulaters and dc to ac converters.

mrhappy42

emaherx wrote:

maplin sell small wind turbines and solar pannels as well as regulaters and dc to ac converters.

http://www.maplin.co.uk/

search for 'solar'....some magic stuff but did not see anything for wind.

for the solar my laptop is about 2.4A at 19v...one of these panels generates 50W at 16V which gives about 1.8A. The panels also seems to cost about 500 euros. My laptop is old and these panels would have problems.

Capt'n Midnight

mrhappy42 wrote:

I looked into this as well at one stage. The big issue is the 'tower' and the dc2dc converter. However I would recommend that you use a laptop as it has a build in power source so all you need is to plug the 12 or 18 v directly into the laptop (after some smoothing) and let it handle to storage etc.

One company in Ireland and One in Scotland do small wind generators.

www.pet.ie I think is the web site.

Laptops
use less power
have a built in UPS
usually can run on 90V to 250V

In LIDL you still might find some power meters so you could measure exactly how much you need.

A bicycle dynamo generates 3W for comparison
You could try a car radiator fan motor - it has rotors on it - but probably geared for higher speed.

If there is a stream nearby you could use a car blower fan (bit like a air raid siren) as a water wheel (axel across the stream).


http://www.bullnet.co.uk/shops/test/wind.htm - should give an indication of the size of windmill for power.

http://www.bullnet.co.uk/shops/test/solar.htm - solar panels - don't forget that in winter there are at least 18 hours of darkness per day.

mrhappy42

Capt'n Midnight wrote:

Laptops
use less power
have a built in UPS
usually can run on 90V to 250V

they need a lot less volt than 90 to 250 as you could skip the transformer stage on the laptop, its the voltage of the battery back i.e what comes out of the transformer. The one I have is 19v and 2.4A. At 19V to get 2.4A you would need P=VxI 2.4 * 19v = 50W. Assume that you dont use it all the time and that you have two batteries which you can charge I think this would do it. However the cost is still a few hundered Euro.

Capt'n Midnight

The point was that the laptop adaptor would handle a wide range of voltages, so you'd have more flexabilty in the power source, also using (say) 90v would be less dangerous than mains and you wouldn't need as much copper as for 12V

the rating on the adaptor would also include power for charging the batteries with the laptop running at full power, so you might get away with a lot less.

elivsvonchiaing

From some very rough calcs from what I found here...

http://www.vindmoellegodkendelse.dk/Common/RecomPowerCurve.pdf
Page 24.

I reckon this will never work with 50cm turbine. With 1m turbine you should be okay with reliable 20kph winds or with with higher gusts. Very rough assumption applied - area of circle 50cm vs 18m. Yield of 50cm 0.07% of the 18m version. The yield of course will be less than this.

[Edit] original post based on radius [/EDIT]

emaherx

wind turbines might not be on the maplin website. But they are in the instore catalog.

can't rember what size they are or their power output but they are there.

po0k

I'm building a wireless router jobbie, and will be using wind as the primary power source, probably backed up with a battery to fill in the "gaps" in wind strength.
The entire system should be running off 12V DC.

Off-topic, but related:
At the moment I'm trying to find sources for a board with low power cpu (Transmeta, LV/ULV Celeron or something) that has 2 PCI slots.

I'm pretty sure I can't just slap in a riser to expand once PCI slot into 2.
All the boards I've seen are either "proper" embedded SBCs or are over-featured for what I need (basically miniITX boards or 5.25" form-factor).
I could slap together a temp test-bed, but that would only be suitable for getting the linux side of things working, and I need to have it running off wind in 6 months time.

emaherx

SyxPak wrote:

At the moment I'm trying to find sources for a board with low power cpu (Transmeta, LV/ULV Celeron or something) that has 2 PCI slots.

I'm pretty sure I can't just slap in a riser to expand once PCI slot into 2.
All the boards I've seen are either "proper" embedded SBCs or are over-featured for what I need (basically miniITX boards or 5.25" form-factor).
I could slap together a temp test-bed, but that would only be suitable for getting the linux side of things working, and I need to have it running off wind in 6 months time.

considered via technologies they have low powered cpus some of wich dont even require cooling. as well as small form factor main boards which support up to two pci cards (think riser card is reuired though)

http://www.viaembedded.com/product/epia_mini_itx_spec.jsp?motherboardId=21

po0k

Yeah, I was looking at the miniITX range and the Via Eden platform.

Hopefully I'll find a board with the featureset I need
They run off 12V don't they? And they're very low-powered.

Shouldn't be too hard to make it self-powering.

po0k

Looking like the 800Mhz Eden Nehemiah chipset with the CF and PCMCIA slot + 1-to-2 PCI Riser + 2 PCI 802.11g cards + 1 PCMCIA 802.11g card.


Back on topic:
Anyone have any pointers to sites describing average parameter-to-power output?
I'm rather unsure about how to properly regulate the power flow during fluctuating wind conditions.
I intend putting a batter between the wind generator and the machine itself, so that may buffer any dips / surges, but as I've never worked with power supply capable f such large fluctations, I'm a little unsure as to how successful I will be.

I assume the battery will be able to take whatever the generator can throw at it?
I'm still mainly focusing on getting the machine itself running, but I'd like the power side of it to be rather nifty aswell ie automatically switching supply from generator on/off when the battery could take more charge/is full, though I'd rather have the battery charged and ready as a backup power supply, with the machine being powered "directly" through the (regulated) wind generator.

emaherx

I think that due to such large power floctuations, you will need to run the sytem off of the battery and use the wind generator purely for keeping the battery topped up. you might want to consider a solar panel as back up for those calm days (rare and all as they are)

po0k

Yeah, I was thinking much the same.

I'd like to have it running off solar panel aswell (like you say, as rare as they are ) but I've no idea as to price/power or sources.

Anyone care to offer some links?


After looking at the specs for the Mini-ITX boards I reckon it can be run off 20-40W fairly easily.
Maybe 50 if I've to use a hard drive.

emaherx

I know I alredy mentioned this but maplin are worth a look.
There are no wind turbine listed on the web site but they are in their calalog.

I think I have one at home (catalog that is). I will look at the spec and prices and post later.

po0k

Cool, I'll give them a shot at some stage

mrhappy42

emaherx wrote:

I think that due to such large power floctuations, you will need to run the sytem off of the battery and use the wind generator purely for keeping the battery topped up. you might want to consider a solar panel as back up for those calm days (rare and all as they are)

might consider multiple batteries in parrallel i.e better voltage regulation i.e greater capacitance.

Stoner

Just as a matter of interest, are you extected to run the pc from a source that will kept it going 24/7. I think that charging a battery with a dirty supply to run a labtop for 1 hour would be cheating a bit.
Obviuosly it woud ba a great buffer, you could keep is simple by getting step up 12/240Vac dc/ac units that you can get for cars, you can get 300Ws easlily from them, that way you could charge any cheapo car battery and supply the labtop directly (as 40Watt seems a little short of the power requiremnts IMHO) With this structure in mind you can break the project into simple steps, the 12vdc to 240Vac converter can be researched easily from the web, or you can buy one from CPC.co.uk. It'd deff try to charge the car battery though as they are the easy to deal with most DIY supplies run from these things hooked up parallel. I guess it comes down to the scope of your project, can you just buy a solar panel, will it need to run 24/7 etc, do you actually need to build the mec to generate the power.
It's an interesting project, if you have to get into the nitty gritty cleaning up the supply will be very important, regulator circuits are easily available and can be built on breadboards, or bought as a packaged circuit board, that way it would look like you designed and made it yourself even though its really just an airfix. If it was me I'd try to work a fly wheel in somewhere just for the heck of it.

Stoner

po0k

The board will be running off straight 12V DC.
I'm getting a 12V DC-DC ATX Snap-in module (120W) that will take the stadnard "round" 12V connector off any regulated 12V source.
That 12V source will be coming from a regulator & DC-DC converter to drop the battery voltage to 12V if needed and to smooth out the rail.
The batteries can be charged off any source.
40-50W is plenty for the platform I'll be running.

Stoner

Your in the Biz so I guess, looks like its the mechanics of the whole system is the main part of the project and not the depths of power electronics, but on a tangent I got a special flyer in from CPC about that rectifier, €49.5 ex vat comes with a standard car cigar lighter on one ent and a 13Amp single socket on the other, all smooth and ready to power any 230Vac device under 300Watts

xonencentral

Came accross a new company up the west who have developed a new automatic wind micro turbine, my friend has bought one and won't shut up about how cheap it was, he reckons the parts alone on his DIY disaster "which fell apart with a decent wind" were twice the price of this commercial system and this new system was several times cheaper than other commercial systems. www.surfacepower.com

Moto: Why pay when you can do it for free ..........

mrhappy42

Seems a bit light on detail. Wrote them an e-mail asking for more detial...bit dubious how they get 460 wats.

mawk

http://www.instructables.com/id/How_I_built_an_electricity_producing_wind_turbine/

wham.