Better done with water than solids.   Mature technology and 80/100 efficien=
t

On Thu, 4 Oct 2018, 13:46 Denny Esterline, <desterline@gmail.com> wrote:

> This doesn't pass the smell test for me. Really choking on the idea of 85=
%
> round-trip efficiency.
> Electricity in -> control losses -> motor losses -> gearing losses ->
> winch/cable/pulley losses -> mass lifted.
> Mass lowered-> winch/cable/pulley losses -> gearing losses -> generator
> losses -> grid tie conversion losses.
> Not to mention all the things the system has to do when it's not
> raising/lowering mass, e.g. empty hook return.
> Feel free to apply your own numbers for any of those loss points, but eve=
n
> optimistic numbers
> quickly exceed the claimed numbers.
>
>
> Still an interesting idea though. :-)
>
>
>
> On Thu, Oct 4, 2018 at 3:34 AM RussellMc <apptechnz@gmail.com> wrote:
>
> > Concrete weights stacked to store energy and destacked to provide outpu=
t.
> > It works (of course) but will have difficulty being cost competitive wi=
th
> > other storage technologies.
> >
> >
> >
> >
> https://qz.com/1355672/stacking-concrete-blocks-is-a-surprisingly-efficie=
nt-way-to-store-energy/
> >
> > Claimed end to end efficiency is around 85%.
> > LiIon efficiency said to be around 90%. (Actual figure depends on metho=
ds
> > of charge/discharge).
> >
> > ________________________________
> >
> > A "train" (or multiple units) on a track with cable connection may allo=
w
> > improved ease of charge/discharge.
> > Energy storable per mass is less per distance moved due to non-vertical
> > track, but can make use of long slopes.
> > The excessively enthused could move 'wagons' sideways at top and bottom
> to
> > increase capacity.
> >
> > A single looped cable would allow multiple 'wagons' to be pulled up or =
to
> > descend using existing chair-lift type coupling/decoupling.
> >
> > Masses & heights involved are "somewhat daunting"
> >
> > 1 kWh =3D 3,600,000 watt-seconds
> > ~=3D 360,000 kg.m  (100% efficiency)  =3D eg
> > 360 tonne x 1m
> > 36 t x 10m
> > 3.6t x 100m
> > 360 kg x 100 x 10m
> > 36 kg x 1000 x 10m
> > ...
> >
> >
> >
> > Russell
> > --
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