Re: [EE]:: Operation of water pumps from Wind Turbines

The good old American farm windmill. Not a screw, a submerged flapper valve

On Mon, Mar 31, 2025, 3:45 AM [email protected] <[email protected]>
wrote:

> How about mechanically coupling the windmill to an archimedes screw to
> raise the water. I have seen this work in Holland over a few meters. I'm
> not sure how deep that works to be useful in your case.
>
>
>
> Cheers,
> Martin.
>
>
> On Monday, 31 March 2025 at 19:33, RussellMc <[email protected]> wrote:
>
> > TL;DR / Summary
> >
> > Comments on the following are invited - especially the practicality of
> > using DC powered deep well water pumps to allow direct powering of water
> > pumps by wind turbines across a wide range of wind speeds.
> > Of significant uncertainty is the practicality of powering a 1-5 kW range
> > DC powered pump from a highly variable wind source, and the ability to
> load
> > the turbine close to maximally at all times to prevent damage.
> >
> > _____________________
> >
> > I'm interested in the operation of deep well water pumps powered by WT
> > (wind turbines.)
> > Direct alternator to pump action without batteries or inverter is
> desired.
> > Pumps motors are typically in the 1 kW - 5 kW range.
> > Smaller and larger may happen.
> >
> > In the target application pumps are in most cases powered by diesel
> fueled
> > generators, but in some cases by AC mains power or solar panels.
> > Solar with AC motors has the cost disadvantage of requiring batteries and
> > inverters.
> > Diesel operation is costly.
> >
> > When wind turbines are used the most usual method is to produce 3 phase
> AC,
> > rectify it and store energy in a battery and then use an inverter to
> power
> > the pump.
> > This has the advantage of decoupling the pump operation from variations
> in
> > WT output and wind energy variations. As required the pump may be
> operated
> > at a relatively constant level in start / stop mode depending on mean
> wind
> > energy availability.
> >
> > While grid scale WTs can be operated in constant speed mode and provide
> > relatively stable AC frequency output, this is not practical with WTs of
> > this size. Even if constant speed was viable, energy variations would
> occur.
> > Non constant frequency operation makes operation of standard
> off-the-shelf
> > motors problematic.
> >
> >
> > Application environment:
> >
> > In this application it is intended that the WTs proper, and where
> practical
> > also the alternators, will be constructed locally in countries where low
> > income and possibly also high energy costs make this attractive.
> > This replaces material costs with local labour but means that use of
> > battery plus inverter systems adds substantially to the capital cost.
> > Adequate knowledge and design resource exists in these areas, but more
> > relevant input is alway welcome.
> >
> > DC system:
> >
> > I'm interested in the possibility of using DC pump motors. WT AC output
> > would be rectified to DC and used to drive pumps directly or via an MPPT*
> > system.
> > This presents the DC motor with a variable voltage variable energy power
> > source. Voltage and available energy need to be adequate to start the
> water
> > pump from stall conditions and the pump must be able to provide the WT
> with
> > a full load across its intended power design range.
> > When the WT reaches maximum wind speed and power output furling systems
> > prevent further increases in output. "Dump load" systems to add extras
> load
> > at the top end are conceivable but undesirable if the energy is wasted.
> > Depending on environment two or more pumps may be able to provide a
> staged
> > load.
> >
> > ________________
> >
> > * MPPT = Maximum Power Point Tracking is a system which adapts a variable
> > voltage level input source to a load (by adjusting the load seen at the
> > source so that the energy source is optimally loaded (maximum power out)
> at
> > all times.
> > This can be thought of as an "electronic gearbox".
> > A MPPT controller very usually contains an inverter
> >
> >
> >
> > Russell
> > --
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