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 even
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 output.
> It works (of course) but will have difficulty being cost competitive with
> 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 methods
> of charge/discharge).
>
> ________________________________
>
> A "train" (or multiple units) on a track with cable connection may allow
> 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 t=
o
> 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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