Have anyone compared the feasibility to generate the electric
I have this concrete water storage tank 10m above the ground engineered to have a penstock to be attached to a turbine with the hope to generate electric power at a flow of 125m3/day and stir one efficiency of 80%.please note Ground Water is lifted into the storage tank from an industrial borehole Using an industrial water pump
Please say is this design feasible?
Am I am correct in understanding that this is a design, rather than an already constructed water tank, and that the potential design is to pump against a 10m head to get the water into an elevated tank, then reducing the excess pressure by turning potential energy back into electricity with a turbine?
If so then it is arguable that it would be more efficient in terms of both energy & construction cost to have your tank at a level such that the turbine was no longer required. All the electricity generated by the turbine (and more due to inefficiency) would be saved by lower energy requirements at the borehole.
If, however the borehole pump and elevated tank already exist, or you are deliberately using this system as an energy storage device - so you pump water into the elevated tank during the day with a solar powered pump - then the system makes more sense. However I imagine a second low level tank may be required, otherwise you only generate electricity when people are using water.
Thanks for your question which I have forwarded directly to our RedR KnowledgePoint experts.
Hope you get some useful answers soon!
Kind regards, Leigh
LC Jones RedR KnowledgePoint Moderator
Assuming flow is available at even flow over the day then 125m3/day gives about 1.4lts/ sec. Power(in watts) = dynamic head (in m) x Flow (in lts/sec) x efficiency x 9.81 So assuming no pipe friction head loss and that the full 10m will be available (no residual pressure for other needs) then your flow and height will give about 100watts of continious power. Or 2.4kWHrs/day. Is this enough for your needs? A solar PV system might be easier since it is likely to be more readily available, more cost effective and easier to maintain.
Also in energy terms it would be better to tap the power from whatever is powering the borehole rather than having that pump push the water to the top of the tank. The borehole pump pumps the water from drawdown level to top of the tank but the proposed hydro only drops the water to the ground level.
If the tank is on a hill then uou could get more power by running the pipe down the hill. 20m drop would double your power.
I think more information is needed on the reasons for the tank, what powers the borehole, how much electricity you need (and when you need it), the water use profile during the day through the pipe, etc....
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