12v power from a river?

[squazy84]

wondering if i can get some help here,i need to keep about 4 tractor battery's charged up,they are continuously running a 12 v 6'' fan with a 12 watt power rating , ive been charging the battery's but its awkward to say the least, now there is a river running about 150 yards away, the river runs at jogging pace and is about 16 feet wide at the concrete bridge where i hope to locate a generator of some sort, i have access to car/tractor generators and alternators and can obviously build necessary frames and fittings ect,im looking for suggestions on the matter as its all just plans so far, am i mad??

 

[the snooper]

water wheels with gears to turn a car alternator fast enough, a 240 volt alternator is out as you wouldnt be able to keep the speed regulated

 

[squazy84]

this is what im thinking, i was hoping to use timing belts ect as gears dont much like the water

 

[squazy84]

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?

 

[PhillipM]

this is what im thinking, i was hoping to use timing belts ect as gears dont much like the water

Nylon gears...

 

[the snooper]

v belts would be cheaper then timing belts

 

[squazy84]

well these would just be scrap as we run a garage near by, the v belts would slip when wet i think? it rains a lot in Ireland by the way!

 

[the snooper]

well you cant beat free, we dont get too much sun in england either

 

[brightspark]

if u were to get power from the river for 240v u would need an undershot waterwheel with plenty of power and a governor fitted http://www.google.co.uk/#hl=en&outp...6,d.d2k&fp=a7034d10d8282623&biw=1422&bih=1002

 

[newstick]

river power

Hi ,go to www.alternative-energy-tutorials.com they have a page paraghraph
relating to small hydro dc generation using truck bus old style dynamo.And since river wheel is producing electricity even when battery is full charged ,talk of using dummy load,heater element to dissipate not needed power.Also formula for calculating flow rate and possible power production.Give it a go even possible to use dc motor ,wiper motor who knows.Check out some of the boat sail web sites and see how they charge battery.Wish you success you might even cook a battery

 

[Psymon]

You'd need a PMA plenty on Ebay alternator will need to be spun at 2000 - 3000 rpm continuous to make any decent power but a PMA/PMG will put out loads at 200-300 rpm.

 

[bigtip]

i would suggest a photo voltaic set up is a better bet for you. to get much power from hydro you need some head, the flow is much less valuable. an overshot or breast wheel is impossible without some head (or drop) or some engineering works to create this but an undershot wheel is fairly inefficient. if you do go for a wheel then the gearing required will eat much of what is left of your available power. then you have to transfer that power 150m from the river to your batteries = more losses.
you can get a sort of floating propeller type generator which are primarily for towing behind boats but the output is pretty lame and they aren't cheap whereas a decent sized solar panel with a pwm or mppt charge controller would probably cost less and has no moving parts to go wrong and you can site it closer to your batteries.
i used to have a yard with no mains electricity but a small river next to it and i really did some research on this but i found that hydro just is not suitable for that kind of situation.

hope this helps,

john.

 

[dannyp]

from what i read the guy is after all of 12 watts of power. that really isn't going to be hard, it's not lik it's got to be efficent

some sort of inpeller in the water spinning a permant magnet motor or idealy a brushless genorator, see what output volts it offers and then use dc-dc converters and a pwm cageing box to sort the output to something usefull

 

[jinjahbiscuit]

What we do get in the UK is wind. Plenty of it, and there are loads of websites with free plans for windmills driving pumps and generators of all sizes. Charging some batteries wouldn't be a problem.
Also check out Navitron who do water driven turbines.

 

[Jim_gsxr1000]

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

 

[julianthegypsy]

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!

 

[drum]

http://www.amazon.co.uk/Solar-Battery-Charger-ideal-Caravans/dp/B000R0UBT8

^^£16.

I don't know if you the equivalent of SEPA in Ireland but here they don't like people messing with the waterways.

 

[brightspark]

http://www.amazon.co.uk/Solar-Battery-Charger-ideal-Caravans/dp/B000R0UBT8

^^£16.

I don't know if you the equivalent of SEPA in Ireland but here they don't like people messing with the waterways.

its doubtfull if u would get away with channeling a spillway to funnel the water in to your wheel as if u didnt have one the water would just go round it as theres less resistance

 

[squazy84]

ironically enough the river used to have an old water driven mill on this exact spot but yes the waterways people may mot be happy but surely what i plan would have little or no impact on fish life or other aquatic activity, i dont need much power from it just enough to counter the drain of a 10 watt motor, ive tried the solar powered chargers,they are totally useless,perhaps its our weather but they have no effect on the time needed before recharging the batteries,keep the suggestions coming, its all useful

 

[squazy84]

hmm this http://www.ebay.co.uk/itm/12V-600W-...?pt=UK_Sound_Vision_Other&hash=item3a7418f6aa
looks promising for a power source as im sure i can get 600 rpm out of the river