I thought I'd start a thread inviting input on this subject. Has anyone experience of these, their effect on fish, and desirable design features if their installation is inevitable?
Also, has anyone figures for their power output and efficiency? We need to know what we actually gain from these small schemes and balance that against the effects on fish passage etc.

This is set to become a very big issue with the current push for green energy, and a large number of licences for schemes up for grabs.

For myself, I'm very concerned about the potential cumulative effect on migrating fish of numerous small schemes.

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Ten minutes from Tweed, Teviot, and Kale.

I quite agree Curlewcall, one of these has been installed at the headwaters of the Afon Cych, probably with the very best of intentions and at some cost to the owner but also at some cost to the environment both aesthetically and ecologically.

I know the guys who've tried to gear up the turbine to generate a decent output for the given head of water but it's not too successful so far which makes the scheme particularly irritating; it isn't saving much grid power from being consumed which was, of course, its raison d’être

The valley which the leat and weir have been installed in is an SAC and, amazingly, all relevant permission has been obtained none the less it looks like an ugly substantial barrier to migratory fish to me.

The in stream structure is achieved by concrete block work (!) and stone gabions - try getting permission for that for any other in stream project and see how far it gets.

Give me wind turbines any day, these little hydro installations will undoubtedly be problematic for river ecologies in coming years.

Strange to say I heard nothing about the proposed project and that’s in an area where you need to bribe the planning office to build a bird box - it suddenly appeared so be alert, there are great powers at work!

I'll try to dig out some pics.

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Musha rig um du rum da

OK here they are..............

The river's retained by the brand new obstruction and partially diverted by gabions before being filtered at the particularly ugly area defined by blockwork






The filtration unit






I was quite upset to see this installation, it's between two of my kick sampling sites in an area which I'd previously seen as relatively unspoiled by insensitive construction - it's completely at odds with the river and badly located in terms of hydrodynamics.


One of these mini hydros on it's own is questionable; dozens of them could pose a real threat to a small river. The amount of energy expended on creating the retaining structures, leat, turbine, gearing, wiring and the battery storage is pretty considerable - and that's before the impact on the immediate environment is taken into account.

Are mini hydros worthwhile and sustainable - it's a difficult one and unfortunately I'm not at all sure of the answer. As an angler I see this particular installation as a threat but in the long term and given the greater threat of global warming ...........derrr.

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Musha rig um du rum da

technically that's micro hydro, not mini. That particular one looks a bit useless to me, but then I haven't any experience of low head turbines of that nature.

I've installed the small archimedes screw type's and I've been doing feasibility studies for some larger schemes on different waters. I'd tend to only be looking at reusing existing structures such as weirs, turbines and mills as this has a certain historical importance as well as providing important renewable energy and potentially cash into often tired rural economies.

Micro hydro schemes can work well and for the most part don't involve the installation of complete barriers across the channels width. The head from that installation just doesn't seem to justify the expense to me.

I also can't see the EA consenting a scheme like that on any of my rivers, from Dorset, Somerset, Wiltshire, Exmoor, Bristol/Bath or Glos, and I'm looking at suitable examples in almost all of those places...

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ugly casts catch fish too
http://nadder-diary.net

Thanks diawl bach and Malcolm, it's good to get input from people with direct experience, and or, involvement.

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Ten minutes from Tweed, Teviot, and Kale.

That's shocking! Thanks for posting the pictures. We're expecting a lot of "run of the river" micro hydro applications up here in Scotland

Just to clarify, I should have made the title micro and mini hydro.
Can I edit it?

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Ten minutes from Tweed, Teviot, and Kale.

Warren's got one:
http://141207.blogspot.com/

These could be 'THE' major threat to our rivers.they will be rushed through the planning proccess with scant thought to migrating fish in the MAD headlong rush for RENEWABLE ENERGY.
complete Cr*p

Jim

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The Fishermans Friend is the Flirty Fly,Fickle Food for Fleeting Fish.

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