Biggest wind farm

[Goaty]

Shame, I'm the same. I had interest in renewables and efficiency of resources back in the 80s as a teenager and because I've never been career or money oriented, I've never been in a position to play around with such.

 

You could of had several pumps, it would of spread the timeout maintainence or failure risk.

 

 

 

 

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[matelot]

Even though we would lose energy, why not pump water by surplus solar power or whatever in the day uphill to a reservoir, then release it by night or at peak times to create hydroelectric.

 

As others have said this already happens. I think a drawback is that the process loses quite a lot of energy.... There are also limited valleys where you can have two dams.

[djbobbins]

Perhaps we should find ways of harvesting the energy of the ravers.

Converting mdma into electricity, that would be cutting edge technology.

 

 

http://inhabitat.com/green-a-go-go-at-londons-first-eco-disco/

 

It's been done, a few years back...

[matelot]

As there is a 30 metre drop from the top field and house to the stream at the bottom I calculated the family electricity use was about 30kWh a day and could be supplied by storing 300 tonnes of water in a top pond and running it to a turbine by the stream. What I never worked out was if a ram pump could lift that much water from the stream in a day.

 

Why bother with a top pond? Why not just dam the stream and have a hydro scheme there?

[djbobbins]

As others have said this already happens. I think a drawback is that the process loses quite a lot of energy.... There are also limited valleys where you can have two dams.

 

 

It does happen in a few places already and at different scales, for example Dinorwig in Wales and I think Cruachan in Scotland. There are plans IIRC to convert a quarry somewhere into a pumped storage facility.

 

Other technologies that have been looked at in the past are compressed air storage but the efficiency is low and only a small range of compression can be used (i.e. once the pressure drops below e.g. 50bar it's no good for running a turbine). I think ecotricity looked at clifftop storage tanks a while back - pump seawater up the cliffs when electricity is available, generate when power is needed.

 

Two of the more recent ideas are power to gas (creation of hydrogen for injection into the gas grid) and demonstration projects are currently operating for commercial scale battery storage. Battery projects are getting built which will store up to 5MWh of power; whilst this would be enough to power an average household for 10 years the main reason is for providing short term frequency response.

 

Some of the energy suppliers in Europe are also offering domestic battery packs - about the size of a kitchen wall cupboard.

 

Personally I think one of the best things that should happen is a combination of smart metering, aggregation of battery storage and the roll-out of electric cars. My theory is that most people with an electric vehicle won't use the full charge for their journey, so the car would still be useful if 60% charged at 7:30am. Therefore if cheap power can be put into the battery at 2am when there's no demand, then sold back to the grid when it is required at 7am, 1000s of car batteries across the country can be used as aggregated storage.

 

Smarter appliances are also coming - freezers that will have intelligent controls to switch on and off dependent on electricity grid conditions as well as temperature - e.g. to get themselves really cold overnight then not use any electricity during the morning demand peak.

[openspaceman]

As others have said this already happens. I think a drawback is that the process loses quite a lot of energy.... There are also limited valleys where you can have two dams.

 

Yes it loses 25% at Dinorwig but is still profitable because it buys electricity much less than it sells it. It has a 600 metre drop and can supply 2GW for a couple of hours if necessary, during slack periods some of the turbines are kept running in compressed air so once the water hits them they can generate within 12 seconds. Interestingly, to me, is that the turbines are some way below the bottom reservoir. My take is this is that this is to stop cavitation when pumping back up the hill. I believe for a similar reason submarines can go faster when deeply submerged than on or near the surface but I haven't seen our resident expert on this post recently.

 

Dinorwig was built in 1984 when nuclear power supplied 25% of our electricity, now all the original magnox facilities are closed, including the nearby one at Trawfynydd (the only inshore magnox which used the lake to for coolant water and coexisted with a 30MW conventional hydro power station which in 1931 supplied all the power needs of North Wales). The walk round this lake is an easy 8mile amble with a café at the end which was the workers social club. Incidentally there are many many more people employed here since 1995 when it closed after 30 years or generation decommissioning it than operated it. It produced 900MW which was enough to power North Wales when it closed.

 

As you leave the café and head back down the A470 you can see the 1960s dam for the top reservoir of the Festiniog plant.

 

 

There were plans for pumped storage schemes near Edinburgh and Exmoor using cheap power from Torness and Hinkley, whether renewables make these worthwhile time will tell.

 

Why bother with a top pond? Why not just dam the stream and have a hydro scheme there?

 

Because the farmhouse is at the top of one side of the valley and the stream flows through the bottom of the valley, damming it would flood the whole valley as there is little fall for the stream through the valley. The reason for pumping the water to a top reservoir was that the cheapest turbines are impulse ones and these can be throttled by having a governor alter the size of a nozzle to keep the turbine running at a set speed. Nowadays I guess you might run a turbine asynchronously and chop and reform the waveform to maintain 50Hz under any load.

[wills-mill]

 

 

Because the farmhouse is at the top of one side of the valley and the stream flows through the bottom of the valley, damming it would flood the whole valley as there is little fall for the stream through the valley. The reason for pumping the water to a top reservoir was that the cheapest turbines are impulse ones and these can be throttled by having a governor alter the size of a nozzle to keep the turbine running at a set speed. Nowadays I guess you might run a turbine asynchronously and chop and reform the waveform to maintain 50Hz under any load.

 

 

The NT at Haslemere are running a very neat modern ram called the PaPa pump. They are wonderful things, most intriguing- Water Powered Technologies | Papa Pump the 21st century hydraulic ram pump

 

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[Mike Dempsey]

I have read about ideas for a hydro electric scheme which would dwarf everything built in the UK so far. Planned for up near Inverness iirc the return canal to get the water back up to the top loch would be a lot bigger than the Panama Canal the figures for the output were massive and it would cost a packet to build. Will probably not be built due to the investment required from the government/public sector. If it was to be built it would secure a large percentage if not all Scotland's power needs. Still be a lot better than nuclear though. Its just a pity the Scottish government don't have the balls to do this themselves and secure future electricity needs for the country without the greedy power companies being involved.

[Rich Rule]

Perhaps we should find ways of harvesting the energy of the ravers.

Converting mdma into electricity, that would be cutting edge technology.

 

It would have probably been easier to explain to the kids that they were eating their 'sweeties' to help them generate electricity. haha.

[openspaceman]

The NT at Haslemere are running a very neat modern ram called the PaPa pump. They are wonderful things, most intriguing- Water Powered Technologies | Papa Pump the 21st century hydraulic ram pump

 

 

Yes I have seen these and the many home made ones on the web, we had a couple at Leith Hill but the water got contaminated by sump oil so they had to install mains.

 

Anyway the papa site gives some figures and it looks like one of these pumps could pump about 2 tonnes up the hill in a day with abstraction of 73 tonnes of water from the stream, so filling a 300tonne pond would be problematic. Also costs for the pump run at about 2000 quid.