Stung by the hike in electricity prices, I've decided to have a go at making a water wheel generator.

There is a great depth of knowledge on this site and I'd be glad if anyone who has experience in using deep cycle batteries, 12 to 240 Volt inverters to power a house or to help with the electricity demand, I'd be pleased to hear from you.

We have the stream and I should be able to make a leat, launder and overshot wheel without too much difficulty. The help I'm looking for is in gearing of the alternator, battery capacity and size of inverter and anything else I've not mentioned through not fully understanding the whole job.

I look forward to your replies.

John

check this diy build out

go on, give me a click......

That's a pretty cool idea. - Quite well researched and executed. A friend at work has spent the last year doing something similar -making a small windmill generator - I must ask him how he's doing with it...

Thank you for that Andy, it is the kind of thing I'm looking at doing but wonder how durable the marine ply would be over time. I was thinking about making the wheel frames in stainless steel with just the paddles being in hardwood. It looks like the diameter of his wheel is probably about 4 ft which is what I'm looking at building. I'd prefer not to pay out over £100 for a generator if I could run one from a car sufficiently quick to provide enough charge for the batteries. This is the point where I leave my comfort zone and would be pleased with some guidance.

Steve, I'd be grateful for any information you can get from your friend. Thank you.

John

The advantage of wind power is you don't have to pay anyone for using the wind. With a water wheel you have to pay for the privelage. Never could work that one out...
Good idea though!

Ben, how so?

"With a water wheel you have to pay for the privelage. Never could work that one out... "

I think that you need a licence from the water authorities to run a water-powered generator...

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Originally posted by David Jenkins
I think that you need a licence from the water authorities to run a water-powered generator...

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Yes thinking about it David you're right. A DoE licence is needed to take water from a river or stream.

Leaving legalities aside the cheapest and easiest way to use wind/water/solar is to link a 12v alternator straight to a 12v immersion heater, you need a battery as well to kick start the alternator excitation.

Thank you BT. What I am hoping to do is to switch off the Mains and hook up to my own 240Volt supply run by the water wheel, alternator, deep cycle batteries and 12Volt to 240Volt inverter. I believe the household supply is 100Amp but in normal use, only a fraction of that would be drawn. What I do not know how to calculate is what how the Wattage used in the house relates to the Wattage drawn from the batteries. Sorry for being a numpty.

240v @ 100A = 2000A @12v (quite a lot ).
And of course really you need to add in a little extra as inverters are far from 100% efficient.
Aiming to go mains free is quite a high expectation.

Did anyone see 'Its not easy being green'? Dick Strawbridge and his clan in a farmhouse trying to be self sufficient.

They had a stream and the water wheel was about 12' diameter if I remember right, and that was just big enough to power the lights!

Clickerty Click!

Thanks Ben. Apart from when the washing machine is on I'd have thought that our general consumption would be quite low. I'd need to take some meter readings to put numbers on it but apart from the central heating boiler we are only talking lighting, telly and computer.

Coozer, I did watch that series. If it needs a 12ft wheel just for the lights we could be dead in the water!!

[Edited on 20/2/11 by John Bonnett]

I agree with Britishtrident - something a 12v immersion heater in your boiler or geyser is the answer or get a paraffin fridge and use a 12v element in that instead of flame- I would think that batteries are incredibly expensive for the power they afford (not tested thought tho' and an inverter capable of supplying that peak, and if you can avoid that then there might be value in what you do.

You need to put a logging ammeter on your supply for a while to pick up on your peak current draw and daily draw before designing anything. It will also give you a good idea of where savings can be made and what storage and charging capacity is needed.

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Originally posted by coozer
Did anyone see 'Its not easy being green'? Dick Strawbridge and his clan in a farmhouse trying to be self sufficient.

They had a stream and the water wheel was about 12' diameter if I remember right, and that was just big enough to power the lights!

Clickerty Click!

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http://www.heatpumps.co.uk/types.htm might be of interest (particularly the bit about hydro powered heat pumps)

I think BT has the right approach, the less you convert the energy teh less you loose. So leaving it as 12v dc is probably best. Using it to preheat a tank of water would make your boiler do less work.

You can also look into backing the stream up slightly to get more head, though this depends on your location!

I do think that this is just one aspect you could look at though, it might be more economical to just insulate your house more!

someone check these sums and assumptions please!

if the stream is flowing at about 10 litres per second, and you can harness 25% of the energy as it falls one metre, is that not a meagre 25w that you would have?

Assuming 10 litres is 10kgs and thus roughly 100 newtons.

I recall from the Dick Strawbridge programme that you can power a waterwheel for free so long as only a certain amount of water passes over it in a given time. Dick's wheel passed a bit too much and he either had to pay or bypass the wheel (can't remember the outcome).

I wonder if it would be more feasible to have some fitted to the gutter drains, and the sink drains (but not the toilet drains, I don't think they'd work too well) or maybe even one as the starndard water pressure comes into the header tank

John,

Surely you would be better putting it back into the mains. That way you get the feed in money.

With this (admittedly crazy) scheme, you get more money for the power that you generate than you pay for power. 20p/kWh under the present scheme for small hydro. (£1600 per year per kW)

http://www.fitariffs.co.uk/

You wouldn't need to store energy, as any extra would just go back into the grid. I guess you need some electronics to control the phase of the power that you are generating and sync it to the mains, but it can't be rocket science.

So, if you build the hardware (at 12v) and find its generating a decent amount of power then it might be worth investigating how to feed it into the mains.

I know a guy who uses a car alternator attached to a windmill. He replaces it with a new one every 18months. This would correspond to about 30mph*24hours*500days or 360,000miles, I guess it runs about half the time as you wouldn't expect an alternator to last that long.


Go for it,

Matt

Thank you Matt; another possibility to lower my electricity bill.

I've done a bit of research since my first post and there is an opinion that a water wheel will not generate much power because it rotates too slowly and that a water turbine is the way to go. However, if the wheel and water flow will allow for suitable gearing of the alternator, I cannot see why it would not work just as well. A wheel would certainly be a lot easier to build than a turbine.

Another problem that I'll have is the sheer distance of the stream from our house; something like 100yds. I'd imagine that it would be best to site the batteries and inverter close to the wheel and use 2.5T&E armoured cable to bring the 240Volts up to the house.

Thank you all for your very helpful and considered replies.

John

Ideally you would get the voltage as high as possible. Realistically in this kind of setting 240v is high enough (especially when there's water knocking about). That does of course mean having any batteries used outside and lead-acid type batteries don't enjoy cold weather. This of course is irrelevant if you're just going for immediate use / back onto the grid.

I think I would investigate the possibility of a something more like a turbine running through a pipe. You have the Dam wall, then fit a Pipe, similar to a drain pipe at the base of the wall - this pipe could then channel a lot of water under high pressure, driving a "turbine" of some description.

It wont look quite so quaint, but essentally I think this is how hydro dams work. Use the water at the base of the dam as it is higher pressure. Another advantage would be less maintenance, flood proof and will be quieter I guess.


Excellent project though and well worth looking into


. Wish I had a stream in the garden - So do our ducks.....

Just bridge them meter like them chavs do

Thank you karlak I'm sure you are right but I'm looking to do this the Locost way and want to make as much as I can. If I could find plans for an easy to make turbine I'd certainly have a go at it rather than a water wheel. There is not a huge fall on the stream as it flows through our land so arranging for a sufficient drop might be a problem for a turbine.

Another problem is that I do have my next car project to do and I'm quite anxious to make a start on that so, as Disraeli or was it Gladstone, who said, "So much to do and so little time to do it".

The up side is that I'm never bored.

John

I am actually doing a univeristy project on water power... Building a small scale microturbine to demonstrate the principles..

If you have a low head but sufficient flow rate then something like a Kaplan (axial for very low head or impulse for more head) turbine would be your best bet.

You should be able to build one out of "simple" materials.... Bits of toilet soil pipe, ducting etc... if you look around you should be able to find something pre-made to use as the actual turbine wheel... Be it an old centrefugal fan or something...

I wish I had a stream suitable for this sort of thing, the possibilities are pretty endless!


Another thought.... you could use a water wheel (nice and slow rotation) to directly drive a refrigeration compressor.... Build that into an air/ground source heatpump assembly and then that would create all the heat/hot water you could need... An Airsource heatpump is an extremly simple concept, just need to understand how a fridge works, and then build something that works the other way around.

This is one of the best sites for all this sort of stuff (linked to hydro, but the site has links to off grid, batteres etc).
The best battery source if from forklift trucks, but dont expect to pick them up cheap!

http://www.otherpower.com/otherpower_hydro.html

I looked at generating my own power,(4 or 5 years ago now), I was using 20kWh/day, and the batteries for 3 days autonomy (because I was looking at wind power) was about 30K - and they don't last forever. I would have needed to have a generator too so I could run my welder, and also for when there is no wind for more than 3 days. If your water supply is good, you will not need much storage - just enough to cope with peak use. You may even avoid this amount of batteries if you haev an auto run genny that kicks in if your batterys are down to (say)30%. In the end, I changed all the bulb inside to low energy, replaced the fridge and freezer that were bot 15 years old, changed outside floodlights to metal halides and a few other cheap changes, and got the average kwh down to 15/day, which was the cheapest thing to do.

The first think to do is measure how many kwh/day you use.
The do everything possible to reduce this: The cost of battery storage is truly horrendeous:
Conside creating a drying cupboard/room rather than a tumble driers etc.

Anyway, the otherpower website will tell you as much as you want to know!

Regards
Hugh

I keep thinking about making a combined heat and power unit, a small diesel engine such as a kubota digger engine or a small Peugeot or Vw engine driving a 10 or 15 kw alternator and set up to run only when heating or hot water is required .
The thing to do though would be to get connected onto a feed in tariff so as to be able to sell the electricity to the grid at a higher rate.The main snag would be to get the feed in tariff you need to have a set up installed by an approved installer, maybe you could get the smallest possible solar cell install and feed in the spare electricity using the meter etc for that.
Paul

Always interested in this sort of thing & wish you the very best of luck, please keep us all posted.

As for water power, a friends family own an old mill which they converted. One of the things in the deeds is the 'right' to water 363 days a year from the stream that runs past their garden. This is fed from a reservoir at the top of the hill. (you don't get water on Christmas day and Easter day). Suspect as they have something in their deeds you'll need to be very careful how you get the water power.

They keep looking into it but the last time they looked 10 years ago it wasn't cost effective. It probably is now - but they're too old to bother with it.

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Originally posted by John Bonnett
Stung by the hike in electricity prices, I've decided to have a go at making a water wheel generator.

There is a great depth of knowledge on this site and I'd be glad if anyone who has experience in using deep cycle batteries, 12 to 240 Volt inverters to power a house or to help with the electricity demand, I'd be pleased to hear from you.

We have the stream and I should be able to make a leat, launder and overshot wheel without too much difficulty. The help I'm looking for is in gearing of the alternator, battery capacity and size of inverter and anything else I've not mentioned through not fully understanding the whole job.

I look forward to your replies.

John

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Originally posted by twybrow

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Originally posted by John Bonnett
Stung by the hike in electricity prices, I've decided to have a go at making a water wheel generator.

There is a great depth of knowledge on this site and I'd be glad if anyone who has experience in using deep cycle batteries, 12 to 240 Volt inverters to power a house or to help with the electricity demand, I'd be pleased to hear from you.

We have the stream and I should be able to make a leat, launder and overshot wheel without too much difficulty. The help I'm looking for is in gearing of the alternator, battery capacity and size of inverter and anything else I've not mentioned through not fully understanding the whole job.

I look forward to your replies.

John

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almost guaranteed you will be breaking the law.... you cant 'extract' water without the Environment Agency license. even if the water goes back into the stream afterwards, it is not allowed. You can use 20m3 per day without a license, but that is only 13.9l/min, which wont go that far to powering a generator!

check out The Environment Agency for more info....

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Originally posted by JoelP
I think BT has the right approach, the less you convert the energy teh less you loose. So leaving it as 12v dc is probably best.

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Originally posted by hughpinderThe first think to do is measure how many kwh/day you use.
The do everything possible to reduce this: The cost of battery storage is truly horrendeous:

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