Demon water motor

In message , Andy Dingley writes

Do you know whether they charge a yearly licence fee? My BiL's Dad (now sadly no longer with us) had a 5kW hydro plant[1] on the stream that ran through his property near Zennor, but that was one of the questions I never asked him.

It was originally 110v DC when it was installed, when the house was built in the mid-'30s, but the dynamo was replaced by a 5kW 240v 50c/s alternator in the '50s. When almost all the other electrical equipment was off, mostly overnight, all the spare power was dumped by immersion heaters into big, cellar-mounted, insulated water tanks (supplied from the house's own spring, as was all the house's water including drinking water) giving almost-unlimited hot water.

Now that's what I call energy security! Do you know if the plant is still in operation?

NHH

Oh yes. I have a feeling that the tanks may have provided most of the heat for the central heating too, with the oil-fired boiler just topping-up if need be. I was never actually shown the tank installation, only the turbine house.

Unfortunately, I don't. When he passed on, the house was sold, and we have no contact with the new owners.

ObSE: I'll be at Rushden (I hope) for one day, probably Saturday, over the coming weekend - anyone else planning to be there?

I'd be amazed if they didn't.

from the

I don't think you need a licence to extarct the power but you will for the water, even if you are just dumping it all back in a few hundred feet lower down. You don't need an abstraction licence for less than 20m^3/day.

Say 20m head so roughly 20 * 0.23 * 9.81 = 45W available but you won't be able extract all that, 60% effciency = 27W realistic output. Oh dear...

Surely there has to be some sort of controlled exit otherwise the wasted water would put a braking effect on the wheel.

Mart>> >>> Not clear on the photographs where the water gets out???

If a pelton wheel is running at the optimum speed, water leaving the buckets should be 'dead' i.e with no remaining velocity or pressure head

- so it just falls out of the bottom of the casing!

NHH

No. It's a Pelton. if it's perfectly matched between nozzle & flow, the exhaust water should just "stop" in mid-air and then fall out.

For other turbines, then yes, that would be an issue.