hydro power

[emlclcy]

has this topic been broached much?

I keep looking at the sluice gates and seeing all that power going to waste.

wacky idea but on my stretch the water moves depending how busy the lock is. soooo if you had a 6ft square funnel in the water would the water velocity increase at the funnel output spout - the whole thing is underwater facing current flow and attached to your stationary boat.

slow moving water is pretty powerful, we got caught out tying up the stern without realising the bow was moving out, we couldn't stop it and took 5 people on the centre line to pull her back!

[Rendelf]

Assuming you're on a river, the current is much stronger in the centre than at the edges. If you did build such a funnel, you'd need some sort of small peleton device to harness the kinetic energy from beneath the water?

 

Also, any boat moored upstream of you would reduce flow.

 

If the flow is quite strong, you might have better luck with a water wheel. You could then gear up to create enough RPM to generate a useful amount of power.

Edited October 26, 2015 by Rendelf

[Scholar Gypsy]

You might like to ask Romney Weir, which regularly tweets about the two Archimedes Screws it has attached.

 

 

Some better pictures here. Video here.

 

Peak output 300 kw which should keep your batteries charged!

 

I wonder if you want a portable system to drop into the bywash channel at the lock, with a longish cable to get back to the boat (you wouldn't want to moor on the lock landing, would you ....). Or else you could hide a couple of batteries behind a bush, to shorten the cable run.

Edited October 27, 2015 by Scholar Gypsy

[Tony Brooks]

This is going a bit off topic but I just do not understand why we are installing loads of solar that stops working at night and wind turbines that stop working when there is no little wind when there must be thousands of site of old water mills across the country. Start with every weir on the larger rivers and gradually work out to the smaller tributaries.

 

Water courses tend to be most active in the winter and run all day and night. I would have thought suitable turbines/screws and generators could be UK built and the solar inverters will mate the output to the mains.

 

I get the impression the EA are actively anti hydro.

[nicknorman]

 

I get the impression the EA are actively anti hydro.

Maybe something to do with flooding. Inserting a hydro turbine causes "resistance" to the flow which would decrease the flow of water and thus increase the potential for flooding. I suppose bypasses could be installed but it would all get a bit complicated.

[Scholar Gypsy]

Maybe something to do with flooding. Inserting a hydro turbine causes "resistance" to the flow which would decrease the flow of water and thus increase the potential for flooding. I suppose bypasses could be installed but it would all get a bit complicated.

 

That's the beauty of the Romney approach - the equipment can just be lifted out of the water for maintenance (or if the river is in flood).

 

On Tony's point, as part of researching for a talk I am giving this evening on the River Nene I discovered that 5,600 mills were recorded in the Domesday Book. Quite a few of them are still there on the Nene ...

[John V]

Maybe something to do with flooding. Inserting a hydro turbine causes "resistance" to the flow which would decrease the flow of water and thus increase the potential for flooding. I suppose bypasses could be installed but it would all get a bit complicated.

 

Possibly it needs looking at from the other end......

 

You already have spill weirs at most points where a mill or turbine would work, a slight modification would allow a turbine feed at normal water levels (say in the form of a cut-out in the weir) but still allow the weir to work as normal during flood conditions.

[emlclcy]

 

I wonder if you want a portable system to drop into the bywash channel at the lock, with a longish cable to get back to the boat (you wouldn't want to moor on the lock landing, would you ....). Or else you could hide a couple of batteries behind a bush, to shorten the cable run.

 

yes a portable system, ideally an alternator in a waterproof housing with a turbine inside a cage so it can be lowered into spill weirs with an armoured cable back to the boat.

getting the thing to spin fast enough, I wonder if you could adapt a sturmey-archer 3 speed hub to give you something to tune the rpm

[Tony Brooks]

I am not sure about this gearing up stuff. If you gear to increase speed you automatically reduce the torque (twisting force) so the turbine/screw would need to be fairly large or the water flow considerable to allow gearing up and still be able to drive more than a "toy" generator. I have no idea about the calculations though. I think on low flows and volumes a large diameter water wheel would be required to get sufficient torque.

 

 

 

Maybe something to do with flooding. Inserting a hydro turbine causes "resistance" to the flow which would decrease the flow of water and thus increase the potential for flooding. I suppose bypasses could be installed but it would all get a bit complicated.

 

Tell that to the inhabitants of the Somerset levels

 

All the Thames weirs I have seen have a large spillway that could easily have a Romey style screw system installed without impeading the flow through the main weir. On other rivers they have no or few adjustable weirs so similar would apply although it may mean extending the structure a bit to accommodate the turbine/screw yet maintain flow in flood conditions. On the newer Kennet weirs like Fobney the devices could be built into the weir below the lip so would not impede flow.

 

 

That's the beauty of the Romney approach - the equipment can just be lifted out of the water for maintenance (or if the river is in flood).

 

On Tony's point, as part of researching for a talk I am giving this evening on the River Nene I discovered that 5,600 mills were recorded in the Domesday Book. Quite a few of them are still there on the Nene ...

 

Multiply that 5600 by the number of larger rivers and take 25% as now being possible and you get a very large number. Even if they only averaged a few kWh a day it would produce a significant winter base load and on the large rivers the option of brining them on line to meet surges in demand, natural pumped storage systems without the extensive engineering.

 

I suspect even if the EA would agree we would then face English nature/natural England or whatever.

Edited October 27, 2015 by Tony Brooks

[RLWP]

From here: http://www.british-hydro.org/waterwheels.html

 

 

Basic Formulae

The power produced by an overshot or breast shot wheel is the weight of water passing per second multiplied by the height between the upper and lower water level times the efficiency of the wheel, gearbox and generator.

This can be expressed approximately as:

Power in Watts = 4 x Q x H

 

That's the maximum you have to play with. A lock is usually around 2 metres heigh, so what flow goes through a bye wash?

 

Richard

[Scholar Gypsy]

From here: http://www.british-hydro.org/waterwheels.html

 

 

That's the maximum you have to play with. A lock is usually around 2 metres heigh, so what flow goes through a bye wash?

 

Richard

 

I would guess 0.5 cumecs (cubic metres per second), or 500 litres a second (depending on which units feed into your formula). The flow at Romney weir is often as low as 10, but in strong floods nearer to 300!

 

On the Llangollen, the flow rate according to Wikipedia is about 60 million litres a day. That is 7,000 litres a second or 7 cubic meters a second. That seems quite a lot!

 

On a typical canal with a bit of rainfall, or some water being passed down a flight of locks, my guess looks credible!

[ditchcrawler]

Cotswold Canal Trust have one at a lock http://www.cotswoldcanalsheritage.org.uk/page_id__376_path__0p91p.aspx

[Jambo]

This is going a bit off topic but I just do not understand why we are installing loads of solar that stops working at night and wind turbines that stop working when there is no little wind when there must be thousands of site of old water mills across the country. Start with every weir on the larger rivers and gradually work out to the smaller tributaries.

 

Water courses tend to be most active in the winter and run all day and night. I would have thought suitable turbines/screws and generators could be UK built and the solar inverters will mate the output to the mains.

 

I get the impression the EA are actively anti hydro.

 

The total small scale hydro potential in the UK is relatively modest. I can't remember how modest but from memory it's about a GW or two (I'll try and dig out the numbers). For comparison we already have 13GW of wind and 8GW of solar capacity. As you point out, hydro is a comparatively steady supply so it's well worth pursuing but it'll only ever make a small contribution.

[KenK]

Some years ago there was a boat moored on the K&A at Reading just above County Lock.

He had made a water wheel out of an old Washing Machine drum and fitted plates to the drum to turn it.

It was mounted on a frame hanging over the side of the boat.

The drum was connected to an alternator via a belt.

There is a constant current there so the wheel turned quite quickly and the ratio between the drum and the alternator pulley was fairly high.

As it was silent, running constantly and free, I imagine it was an effective method of producing electricity.

 

Ken

[tidal]

If you can afford it you can buy a taff-rail generator as used by many cruising yachtsmen
But you need a fair bit of flow

[Scholar Gypsy]

A back of the envelope calculation (0.5 x g x density x volume) suggests that the energy released when emptying a narrow lock is about 600 kJ, or around 0.2 kwH.

 

Converted into 12V for charging a battery bank, then about 14 Amphours, assuming 100% efficiency of course.

 

This would require installing a small turbine in the paddle culvert....

[PaulG]

New one at Pershore:

http://www.birminghampost.co.uk/news/local-news/pershore-weir-hydro-station-wins-9306471

 

But strangely it never seems to be working when I've been there.

[ditchcrawler]

A back of the envelope calculation (0.5 x g x density x volume) suggests that the energy released when emptying a narrow lock is about 600 kJ, or around 0.2 kwH.

 

Converted into 12V for charging a battery bank, then about 14 Amphours, assuming 100% efficiency of course.

 

This would require installing a small turbine in the paddle culvert....

I bet you would need more than a 14ah battery and 12 volt pump to fill it in 3 minutes.

[Cas446]

This is going a bit off topic but I just do not understand why we are installing loads of solar that stops working at night and wind turbines that stop working when there is no little wind when there must be thousands of site of old water mills across the country. Start with every weir on the larger rivers and gradually work out to the smaller tributaries.

 

Water courses tend to be most active in the winter and run all day and night. I would have thought suitable turbines/screws and generators could be UK built and the solar inverters will mate the output to the mains.

 

I get the impression the EA are actively anti hydro.

Hydro capacity is tiny compared to solar and wind. The idea is that at times of high wind and strong sun we can turn the polluting power stations off. In years to come battery technology will be able to fill the gaps, or renewables produced hydrogen. Renewables only work when combined with something else.

[peterboat]

This is going a bit off topic but I just do not understand why we are installing loads of solar that stops working at night and wind turbines that stop working when there is no little wind when there must be thousands of site of old water mills across the country. Start with every weir on the larger rivers and gradually work out to the smaller tributaries.

 

Water courses tend to be most active in the winter and run all day and night. I would have thought suitable turbines/screws and generators could be UK built and the solar inverters will mate the output to the mains.

 

I get the impression the EA are actively anti hydro.

already started on the trent when we went through this year they were building the housing for the turbine

[nb Innisfree]

Hydro capacity is tiny compared to solar and wind. The idea is that at times of high wind and strong sun we can turn the polluting power stations off. In years to come battery technology will be able to fill the gaps, or renewables produced hydrogen. Renewables only work when combined with something else.

Problem is power stations can't just be turned off short term, getting them started again involves a long process, too long to be able to fill in demand when winds speed drops or solar reduces. They have to kept running in standby.

[Cas446]

Problem is power stations can't just be turned off short term, getting them started again involves a long process, too long to be able to fill in demand when winds speed drops or solar reduces. They have to kept running in standby.

Yes I meant to say standby not shutdown, massive difference technically, but the concept is the same.

 

..and they can fill in the gaps if the quantity of renewables is high enough, ie like Spain.

Edited October 27, 2015 by Cas446

[billh]

Hydropower on a canal:

http://www.caddet-re.org/assets/no81.pdf.

 

Bill