Hydro power from small river?

[joncooper27]

Hi all some great comments any body any ideas what where to purchase to do/trial a small scheme in England

 

[Woody2Shoes]

Still, very little power. Just enough to power a toaster. With solar you can relatively easily get enough effect to power a modern home. If you add batteries you also have storage. Does it really matter if the power used at night comes from batteries or from the generator?

There are no moving parts in a solar system, they have a long lifespan and are relatively maintenance free. Hydro involves moving parts and therefore maintenance. Also, just from the discussion above it seems that in the UK (like most of the western world) there are a lot of permits, enviromental issues and property rights to consider with hydro.

Yebbut my toaster only runs for about 4 mins per day, leaving the other 97 % of the energy free for some other purpose. There is a big difference between Joules and Watts !! Very basic physics.
PS the simple equation for the amount of energy generated per second by flowing water is simply E=mgh
Where m is the acceleration due to gravity, g is the mass of water per second, an h is the distance that the water moves downwards per second

 

[Woody2Shoes]

Hi all some great comments any body any ideas what where to purchase to do/trial a small scheme in England

There is a small (c. 1MW) installation on the river Rother at Coultershaw Mill in Sussex, you could do worse than ask them how they went about it. They use an archimedes screw, which is supposed to be fish friendly:
https://coultershaw.co.uk/hydro-generator/

 

[Jameshow]

Looking again at your pic it's a decent sized stream.

Let's assume it's flow rate is 2 square ft,

So 4ft by 6" deep.

Let's say want a water wheel which is covered by water at Radius /2 the wheel will be 8ft high by 1ft wide.

However if the flow rate increases by 100% which isn't excessive in a flood then you have water coming over the axle.

If the dam were 4ft deep then the water would start over coming over the top.

If you were in deepest Quebec I'd say go for it but in UK the EA will be onto you faster than the rspca after a cats missed it's lunch!!

 

[Cooper]

I was just telling my daughter about this interesting thread and mentioned about needing permission to generate electricity. She told me that a permit is required but there are automatic exemptions for small generators, that is less than 50 megawatts. This link has loads of other examples but if you scroll down you come to small generators. Electricity licence exemptions
You still need permission from the river authority.
As mentioned she said the Archimedean screw is very efficient and environmentally friendly.

 

[baldkev]

A guy i used to work for went into making hydro electric dams . I think his first was on dartmoor.
From what i was told ( by someone else ) it was a real struggle and nearly sent him under.
I havent spoken to him about it, so thats just what i heard.

 

[Dabop]

Looking again at your pic it's a decent sized stream.

Let's assume it's flow rate is 2 square ft,

So 4ft by 6" deep.

Let's say want a water wheel which is covered by water at Radius /2 the wheel will be 8ft high by 1ft wide.

However if the flow rate increases by 100% which isn't excessive in a flood then you have water coming over the axle.

If the dam were 4ft deep then the water would start over coming over the top.

If you were in deepest Quebec I'd say go for it but in UK the EA will be onto you faster than the rspca after a cats missed it's lunch!!

All the undershot wheels on small streams I have been involved with, the trick is to keep the dam a little bit under the axle height, so flood conditions it will simply flow over the top of the dam, and the wheel height is such that it basically goes to the bottom of the stream- quite possible in small creeks
Of course major floods will overtop the axle- but in those conditions, you simply have to accept that at times you may have reduced or no production from it...
Of course it is always wise to check the local regs first, as they vary enormously around the world (where I am, such a stream as was shown at the beginning would not need approvals (under a certain hourly flow rate, but the dam or weir could not be above a certain cubic capacity before it does need an approval from the state government...)

 

[joshvegas]

Ownership aside.

You have environmental permitting we've dicked about long enough with watercourses to no it's generally a bad idea unless stringent criteria are met.

Who you need to del with would depend on the country. SEPA in Scotland deals with all watercourses. In England the designation of the river means it varies.

You need a licence for abstraction and you need a licence for activities within the watercourse

Essentially you cannot form an obstruction.

You cannot alter flows to the point where during low flows are reduced to 0.

You cannot increase the likelihood of flooding up or down stream.

You cannot release contaminants during construction or use. This includes sediment release during excavation.

You cannot endanger the ecosystem in any way.

It's a really bad idea to just be cracking on with this with our getting the proper paper work. The environmental agencies are not toothless you could have criminal or civil actions against you.

On top of all that you would totally deserve everything you got if you decided to crack on without a care for the surroundings.

 

[joshvegas]

That came across more ranty than I intended.

I am all for renewable and sustainable energy but please make sure you do it right.

 

[joncooper27]

Hi Josh
Thanks for your comments.
The more I look into it the more rules regulation and licences etc involved.
The more I look int I believe the idea would work with batteries due to 24/7 365 days generation why do more people not due it? Is it due to all the rules and regs

 

[ian33a]

We have a river on the edge of our land and riparian rights to it. In effect, the boundary of our land goes to the middle of the water course and I suspect that I could put something on the side as a harvester provided it doesn't adversely affect others who have similar rights further down stream. I can also take 20 cubic metres of water from the river per day if I wish - not that I do. In the case of our river, there is something like 3 metres between the lowest and highest depth (depending upon rainfall) so, if I were to incorporate a generator, I suspect that I would need to take the rise and fall into account. The flow is pretty weedy when the river is low and I wouldn't want to be in it after it's rained as its pretty ferocious.

I read the posts on here with interest because, in theory, it would complement the PV that we also have - flow speed being inversely proportional to sunlight, albeit with some delay for the water to drain off the land further upstream. Trouble is, I can also now see that it's a pretty big and expensive engineering undertaking and possibly even more expensive than buying a decent sized wind turbine (which we had also considered).

It seems like nothing to do with power generation is inexpensive now - everyone company having jumped on the bandwagon.

 

[joncooper27]

Hi Ian thanks for your Comment like anything there has to be a way to harvest this energy it’s just which way any comments welcome I’m still looking into it

 

[PhilipL]

I was interested in this thread (the relative lack of power from a small river) but have just been reading a book on the Swedish iron industry (on the Engelsberg Ironworks from 1975):

"Far into the 18th century, simple open-cast mines sufficed. But when, towards its close, water powered pumps had to be built to bail out the deepest mines, the power had to be transferred from the water wheels by a rod and pinion device several kilometres in length. No adequate watercourse existed nearer to hand." [This cites a Swedish text as source.]

Makes you wonder about the friction in the system.

 

[Jameshow]

If you don't want to interrupt the flow of the river how about a low pressure device like a large paddle wheel like you might find on a paddle steamer?

Harnessing the waters power but not it any way stopping or diverting it's flow.

Say a 8 x 8x1ft paddles mounted on plywood end caps on a 2" scaffold pole and pillow bearings?

Driving a 1kw alternator?

Just a thought!

 

[Dabop]

If you don't want to interrupt the flow of the river how about a low pressure device like a large paddle wheel like you might find on a paddle steamer?

Harnessing the waters power but not it any way stopping or diverting it's flow.

Say a 8 x 8x1ft paddles mounted on plywood end caps on a 2" scaffold pole and pillow bearings?

Driving a 1kw alternator?

Just a thought!

That's what we were talking about before (an undershot wheel)

 

[Deadeye]

Hi Ian thanks for your Comment like anything there has to be a way to harvest this energy it’s just which way any comments welcome I’m still looking into it

The mountain huts on the Swedish Kungsleden have a device that looks like an underwater wind sock - a long, slightly tapered tube that, presumably has a turbine enclosed. Provides lights for the hut and a few devices.
I think it's called "floating run of the river" technology

 

[Jameshow]

The mountain huts on the Swedish Kungsleden have a device that looks like an underwater wind sock - a long, slightly tapered tube that, presumably has a turbine enclosed. Provides lights for the hut and a few devices.
I think it's called "floating run of the river" technology

Yacht have trailing turbines which would work too..

 

[Jameshow]

https://www.sailingtoday.co.uk/gear/gear-on-test/hydrogenerators/

 

[Spectric]

There is a person living in the north pennines that has an old mine adit on his land that he has dammed and uses the water to turn a generator which given the rainful up there must work well, not to far from Alston. Also for water power look at what the miners had in the way of waterwheels, Killhope has a large working on on display or you can see the remains of another large wheel at the old bobbin mill in Caldbeck in Cumbria.

 

[Sideways]

This new installation immediately reminded me of this thread. It's been built onto the end of a weir on a fair sized river, but a lovely new example of an archimedes screw system built by hydropol.cz