Oh boy ... Which national park is this?
http://www.british-hydro.co.uk/download.pdf
http://rapidshare.com/files/133406549/Alexandersson_-_Living_Water_-_Viktor_Schauberger_and_the_Secrets_of_Natural_Energy__1990_.pdf

Ah yes, Snowdonia - Dartmoor, Teign Gorge, me. Are the Navitron ones different from http://www.british-hydro.co.uk/download.pdf ? Do you mean a water wheel that just dips into the passing water? Very little power there.

And what (low) %age of that flow are you prepared to divert down the pipe, so it no longer comes over your fabulous rocks and falls? Maybe you only take flow (a high %age) when it's in spate? Economics.

In my experience, I have found the Environment Agency and Planning Authorities very negative when discussing small hydro electric power plants.

I have been deterred from applying for any licenses by very broad brush attitudes from EA officers with comments like 'of course you will need to change the flow of the water and we can't allow that' and 'the impact on water life will be devastating, what if a fish swims into the turbine'

I feel a lot of this has to do with a lack of education and understanding within the relevant authorities (especially where planning is concerned) and a presumption that all hydro electric plants are the same as the huge civic hydro electric dams but on a smaller scale.

As a result, I'm afraid I have absolutely no experience with building anything like them, even though I really want to.

I hope it is not all doom and gloom and wish bobo the best of luck and would be interested to see how you get on.

A 12ft diam overshot wheel only generates 1 horsepower per ft of width - but huge torque.

Posted By: fostertomA 12ft diam overshot wheel only generates 1 horsepower per ft of width - but huge torque.

Does that torque translate in practice into a higher output for any generator connected to the wheel? If so, how do the calculations work?

So for an overshot water-wheel presumably (the amount of water held on the falling side of the wheel) x (the height of fall during which the water stays on the wheel)? For which you'd need to know the capacity and exact shape of the 'buckets' on the wheel (excuse my ignorance of overshot water-wheel component terminology). And the flow would come in to it, because the wheel would have to be designed to accommodate as much water as possible to maximise power, but would maybe be inefficient if it was handling a lot less than its designed capacity?
I'm intrigued, because there's a semi-derelict mill near where I live; the wheel, about 12 foot diameter, is there but almost collapsed, the mill-house is crumbling, but the mill-race is intact, about a hundred foot run all neatly lined with big pieces of slate, with nice stone sluices all ready to open. The owner has refused to sell the place to anyone, evidently preferring to let it rot, but it had occurred to me that one day it could be a good spot for a little private hydro-electric project.

Jamesingram, do you remember what the height difference was, roughly?

I've been trying to remember more details , I was paid in food and drink (whiskey)for my efforts so my memory of the job is a bit cloudy
thinking about it, the run must have been 100m+ and very roughly the head was around 30m

With a waterwheel you could have some fun operating machinery directly, rather than thinking in terms of generating electricity first. What about a saw mill? Either a geared-up wheel, or a slow cutting straight saw you could feed tree trunks past. I watched a tiny engine at a show geared down with a leather belt with a crank hitched to a large reciprocating saw. He just put a 2 foot tree trunk on the ground and left it to saw away.

Drill
Pumps
Grinding corn
The uses must be endless one you have rotating shafting in a workshop.

Posted By: fostertommechanically driven heat pump, for infinite COP! (in terms of bought fuel)

COP is always defined as (power output) / (power input) - it makes no mention of the cost of that input power. Though it would be a good use of that river, that's for sure since it would be both the source of the heat and the mechanical power needed to make it useful.

Paul in Montreal.

Posted By: fostertomIn this case it meant coefficient of pocketmoney.

Howabout Coefficient Of Parsimony? That would certainly appeal to my fellow Yorkshiremen ;)

Paul born in East Yorkshire and now in Montreal

Excuse my ignorance,how does water run a heat pump & be the source of heat,blooming cold there!

Posted By: Ed Davies
To make sense COP counts the paid-for power in and useful power out. E.g., a split air-conditioner type heat pump in heating mode might have:

It's not paid for power - it's power you supply to run the pump in the form of mechanical work. So my comment still stands - COP = power output / power supplied to run the pump

The heat moved by the pump is not counted in the COP calculation.

Paul in Montreal.

Miked2714.
It seems that it is very dependant on the area you are in and not necessarily the merits of the scheme as to the response obtained from the Environment Agency, I wonder if this has something to do with education rather than policy.
For an example, a project I had some involvement in (not huge technical involvement though so please don't ask me for all the facts and figures) was the reuse of an existing mill with existing chase but having lost its wheel some time ago.
The project was to re-insert an overshoot water wheel into the existing chase (is that the right word?) and use it to generate a small quantity of power and use the mechanical movement for other demonstrations within the old working mill to grind corn etc.
The Environment Agency's response was less than helpful and felt like a huge hurdle jumping exercise with comments like those I posted before being banded about and a renewal of a historic extraction licence being the subject of our misery.
Despite the fact the chase was not dry, i.e. it already had water running through it, and to all intensive purposes the mill was in working order, with the exception of the mill wheel, the EA refused to allow the occupants to control the water on 'environmental and flood grounds'
I would be happy to hear of peoples successful applications as this is of interest to me in the future.