Micro Hydro and Wind Turbine - Closed Loop for Water

A few possibly useful links -

1) http://www.oregon.gov/ENERGY/RENEW/Hydro/Hydro_index.shtml
2) Lucens hydro http://ludens.cl/paradise/turbine/turbine.html
3) Micro hydro calculator http://www.alternate-energy.net/micro_hydro_calc.html
4) http://www.green-trust.org/hydro.htm
5) Ram Pumps http://www.green-trust.org/2000/rampump.htm

If you already have the equipment in place, go for it. If not, the cost of the turbines and pen stock probably will not make this feasible.

1. List of pumped-storage hydroelectric power stations - Wikipedia, the ...
   
2. Images for Pumped-storage hydroelectricity - Report images
3. [PDF] Pumped-Storage Hydroelectricity

It sounds as though you may be converting power back and forth through unnecessary steps. Can you instead consider a run-of-river (or run-of-waterfall) system? (I'm imagining a 100mm x 30m PVC "penstock" feeding a small turbine.)

There is no water naturally available at the top of the hill, though I am lucky enough to get "stock water" there from the rural water supply for the area. This amounts to about 2000 litres per day. My thought was to check the viability of storing the water on site and accumulating up to 250k to be used as a reserve energy source in periods of low wind. So there is no run-of-river capability

The wind turbines would not only directly power the domestic requiremtents, but the dummy load effectively becomes the pump to return "used" water back to the top of the hill (ie recharging the battery).

There are plenty of irrigation pipes that can handle the 200 - 300 kpa that the head will generate at the hydroturbine.

Is it best to use a seperate pump with a smaller diameter pipe to return the water to the reservoir? My thought was that the granularity of control of the water turbine does not need to be that precise as energy generated that is surplus to immediate use would again go back to refilling the reservoir.

Interesting use of surplus wind power generated electrical power that cannot be fed back into the 'grid'.

Yes, you might as well pump water with it. Some of the motor home 12v pumps have quite large head capacities for around the $120 price level.

If you are building your own hardware, look into using the wind to pump water directly. You can use an old tire as a bellows pump, and a long connecting rod up the tower to a an angled, wide crank throw will give a variable stroke to match a variety of wind speeds. A simple centrifugal governor can position the connecting rod end.

I hope you will develop this approach for the home builder, as it uses far less silicon and lead, making power accessible for lower-tech builders, and those with more hours than dollars. A pelton wheel is the obvious choice for the generator, but unfortunately, the square-cube law renders the small ones relatively inefficient. You might want to go to another diaphragm pump as a motor. A dead clothes dryer can provide a very high step-up transmission and a motor to re-build as a generator.

Here in Australia, there is/was a brand of 'windmill' "SOUTHERN CROSS" which were/are used to pump water from underground aqueducts. I would expect that the pumped depth would exceed 30 metres.

over here

Aero Motor

the pump rods are fiberglass, light enough to go a few 100 feet down

Looks much like the 'windmills' here. I can't comment on construction, however they were built predominantly from galvanised steel all those years ago.

You might be able to hook up your turbine to an airlift pump. So just some sort of compressor on top directly connected to the turbine is possible. Something like that used to be for sale. You just compress air, and send it down into a well, or whatever and airlift the water out. If you already have AC, I don't know if it is better have the compressor beside the turbine and pipe the air or have the compressor at the bottom of the escaprment (and pipe the power). For others interested in wind power, I recently saw a link on bbc website where they are designing vertical axis wind farms.

The site said something about them having learned from schooling fish but it was not explained well enough for me.

They have twinned the vertical axis turbines in the farms and have gotten quite the production boost. Second link is about the magnus effect. (which is one of the reasons for the boost). I see potential for having some of the vertical turbines NOT producing electricity. Use them instead to increase the magnus effect and direct the wind more powerfully onto the producing turbines (which would be directly producing power).

relevent links are http://www.bbc.co.uk/news/science-environment-14452133 and http://en.wikipedia.org/wiki/Rotor_ship

This is the pdf of the research on horizontal axis for wind farms with more power per unit area

http://dabiri.caltech.edu/publications/Da_JRSE11.pdf

I think you mean VAWT - so far this is one guy and speculation - let us see him try it for real.

The people I follow, like Paul Gipe, seem to think this type of thing is smoke.

Having installed many micro-hydro units, here's a reality check:

66000 gallons (250,000 liters) of storage = 12 hours of output at 100 gpm (379 liters/min)

With 98 feet (30 meters) of head (and 100 gpm) you will yield approximately 1kVA/hour. Which is good if you can run it 24/7.

How long will it take to recharge that 66,000 gallon reservoir with wind turbines and pumps?

I suspect you will quickly have diminishing returns. And, if you can get enough power from the wind turbines, you don't need the hydro. What kind of flow do you have into the reservoir without a possible wind input?

My two cents to previous comments..

250 000 liters x 30 m head is equivalent to ca 20.8kWh energy stored in water.

Assuming total efficiency of turbine (small Peltier or Francise) & generator in the range 60..80% You could have 12.5 ...17kWh on demand, stored in water.

If pumping system would have 80% efficiency, 16kWh ...22kWh of energy from wind turbine would "recharge Your Battery". Most effective would be to use directly mechanical energy from wind turbine to pump water, without convertion to electricity. But probably using of electrical energy, generated by Your wind turbine[s] to pump water using electrical pump would be easier to do.

If You have 2 x 5kW nominal power, and wind about 4.5 m/s annual average You could expect 20 000kWh annually = 55kWh daily (in average = not every day!)

So, about 2/3 of energy produced by wind turbines could be used directly, and 1/3 through storage system. Because calm (not windy days) are not single, probably this storage capacity (15kWh) may be not enough. May be it is possible to make bigger water reservoirs.

Idea is good. What about economy (justification) - I do not know Your local market prices. Efficiency depends on quality. Quality depend on money. May be using of second had equipment would be more reasonable, than buying a new one. New turbines are very expensive. Good second hand turbine, after cleaning , may be some welding (to remove dents) and "smoothing" of surface can work next 50 years.

When planning: water turbine has its optimum efficiency (70..96%) near the nominal power and head. At lower power (lower water flow q [l/s]) efficiency drops. If Your demand for electric power will be variable, Peltier turbine might be the better choice (has more wide optimal range of work efficiency as a function of amount of water flowing q[l/s])). But if You will find regulated Francis turbine for this head it could be also good. But it must be designed for 30m head or near. Otherwise efficiency may be much lower. The same with generator - maximum efficiency is at about 90% of nominal power.

The best would be to find two-directional pump-turbine, working as a pump in windy days, and working as turbine in calm days. Some industrial pumps are made in this way. They are not as perfect as professional turbines(..90%), but 50..70% efficiency could be possible.

Good luck!