Speaking of micro hydro...

For some time I've been looking at the small river that runs past our property... we don't have access to a long stretch so not much fall available - I've not measured but it can only be a few feet. The water depth ranges anything from about 1ft and quite slow, to about 6ft or more and shifting pretty fast, it's what's called a spate stream. So building anything much in the way of a permanent structure like a large undershot wheel in the stream would be tricky, it'd be liable to be washed away when there was a storm, or be prohibitively expensive to build strong enough.

What sort of stuff is available/do-able that would suit this kind of scenario? Seem to recall hearing about some kind of tethered thing like a giant fishing lure, which spins?

I did toy with the idea of some kind of screw-style thing in the bottom of the river bed, but no idea if it would work.

Hi Austin,

You do sound as if there are a few challenges at your site. Just because you have potential energy rushing by your door doesn't necessarily all you need to develop a successful system.

The first thing you might consider doing is articulating your needs. Do you have grid power already, or are you off grid somewhere? If you really need power, you go to extraordinary lengths to get it, because the alternatives are expensive too.

Anyway, you really need to measure your resource a little more precisely. I show how to survey and measure flow well enough to make microhydro development decisions in my first book, Microhydro: Clean Power from Water, which is available from New Society Publishers at newsociety.com.

Or you can look in the Microhydropower Buyer's Guide, which I helped to create, for a description of how to survey for head and how to estimate water flow. Here's the link:

http://canmetenergy.nrcan.gc.ca/renewables/publications/2427


There are examples of a wide range of heads and flow in the Serious Microhydro: Water Power Solutions from the Experts anthology. Once you know a little bit more about your site, you'll likely find a case study with similar characteristics and learn lots. Teaching and learning by example is the best way.


So, give it a stab and keep in touch.

Scotty

Thanks for the link, Scott!

I'll tak a look at that, thanks. We are on grid at present, so not short of power; it's just a project I'd like to have a go at. My first aim was something that would run the various low loads which are on most of the time, like fridges, freezers, computers ( ) and so on. One thing we have most of in Wales is water... although there would be scope for solar as well; but that's still kind of pricey for what I want, I was really after something I can build at low cost, being an engineering type of bloke.

well I think I've worked out the most likely way to do it, just have to find the money/time to build it ...

I reckon a large-diameter undershot wheel, in a channel running alongside the river. The trick will be to make sure that when the water is low, most of the flow runs in that channel, but it's limited when in spate. More on this if I ever get the project off the ground