12v power from a river?

[bigtip]

That would be ample if you can get it spinning at the required speed. The impeller could be mounted in a large tube to increase chances of 'capturing' the flow and a belt drive to the generator which is up out of the water. The tube would help because, as brightspark says, the water will take the easiest path so when there is a load on the genny and the blades are harder to turn the water will just flow around as much as possible which is harder to do if it is 'channelled'.
Bear in mind that if you used 2.5mm cable from your river to your batteries you would lose about 5 volts across the cables while drawing only 1 amp.

i don't know your exact situation but also worth thinking about floods where your genny/running gear could get a proper soaking and protecting against floating debris.

What kind of solar setup have you tried? How many watts etc.?

 

[CRB]

Dick Strawbridge fitted a realy cool water wheel in his eco house build, channeled the water past a building and build a 12ft water wheel driving a 230VAC altenator, using step up gears, was good for around 5.5 KW

x2

Gets the head required and the 'engineering' was really simple.

 

[MrFluffy]

Youtube is full of working examples and ideas.
http://www.youtube.com/results?search_query=diy+water+wheel+generator

 

[MattF]

I'd have to say go solar for that amount of power. Unless you have head, you will need a huge water wheel, gears etc as well as the dynamo and the cabling etc. Or fifty quid for a panel that would do the job. Absolute no brainer, much as I love water wheels!

As much as I dislike PV technology, I'd have to agree with Julian. Arsing about with any other options is just chucking money away and causing grief for the sake of chucking 30W or so out of a panel. Mount a panel with a higher output Wattage than you actually need facing directly South and you should have no problem covering the draw of that fan and keeping the batter(y|ies) topped up.

 

[squazy84]

where is the best place to buy such a 30 watt solar panel?

 

[julianthegypsy]

where is the best place to buy such a 30 watt solar panel?

Check ebay. A friend of mine has just bought a 100 watt panel for £89 including delivery from Belgium. It only tool a few days and works a treat. He lives in a caravan so has the tv and a few lights and nothing else but he's now working out how he can use up the left over power that is currently being dumped! A smaller panel would do you of course, you could try maplins, they had a 60 watt setup complete with controller last time I looked. Don't forget that power outputs are the absolute max you can get assuming you are on the equator in perfect alignment, you'd be lucky to get half the claimed output. Go for mono panels rather than poly, they don't put out as much, but work far better when its cloudy or overcast.

 

[bigtip]

30w panel won't do it mate. If you're drawing 10w continuously (correct me there if that's not right) but that's 240Wh per day. you can only hope for a percentage of the stated wattage of a panel for most of the day. i can't remember the calculations but you'd need to assume maybe 3hrs of decent output from the panel per day so you need 80 watts really but more would guarantee some slack in the winter. still cheaper/easier than a water wheel even though a water wheel would look much more cool than a crappy PV panel

 

[julianthegypsy]

Get a 100 watt panel and use the surplus power to run a little motor to drive a pretty water wheel...

 

[Justme]

Try asking HERE

 

[bigtip]

Absolutely Perfect, style and content

 

[@Turbo]

run a 12" pipe off to the side and lay in underground on a steep gradient run it through your turbine when it gets a head on it.

if your river is 16 feet wide then it should not be hard to keep a 12" pipe full all the time more or less giving you a constant flow.

 

[normspanners]

http://www.instructables.com/id/Worlds-greenest-water-pump/
It is the head that creates the torque to produce the power so how about one of these to pump water up to a tank/resevoir/ several ibc's 5mts high in a tree or a frame to give you a head to run a high efficiency bucket water wheel for a few hrs to run an alternator?

 

[pidgeon chit welder]

i was thinking about building a simple paddle wheel from 12'' by 48'' alluminum 1/8'' sheet welded to a single spindle held on bearings as the main wheel?

When I was working I saw a pair of aluminium cycle wheels that had stainless spokes with wooden padddles fitted between them set on a long spindle so the paddles were about 9 inches wide by 2 foot long .

Ok this guy tapped a stream that gave him a head of over six feet of water by running a big three inch flexible poly pipe about 150 mtrs up stream . make your so it is undershot instead of over shot though over shot is best as the weight of the falling water is more force full in most cases .
He used a 17 ACR bog standard car alternator for the genny as it has an integral control box and can run at full car engine speed for day and days with out any ill effect .
The three terminals on the 17 ACR's used to be a Field to get the alternator excited . Power out and a return earth being the negative of the battery . I suspect it will be the same on most bigger modern alternators .

You could make a floating arm using a barrel either side of the paddle and fitting the alternator to a chain driven gear set on a frame on the barrels so it is as high up out the water as posssible

An old cycle with gears would be a good place to get most of what you need.
You can anchor the device to the bank etc on ropes or chain so that should the river rise the depth of the paddle will remain failry constant . Just make sure you have some sort of rubbish deflector in place to keep bits of tree or weed off it. Perhaps use the Simplex gear changer device to keep the chain tensioned correctly .

Failing the river idea how about an oelious ( sp ?) system that uses a cut from top to botton 45 gallon oil drum in a safety cage to drive the alternator and site it on the roof of the building or similar .. they do zip round in even the slightest of breezes .