Energy recovery upto 50% using gravity and hybrid supercapacitors
How can gravity and batteries cooperate to save energy? Elevator and crane systems typically use counterweights that assist motors by utilizing gravity. In theory, if there were no losses, using a counterweight would be sufficient to pull a load up or lower it down. However, in practice, fluctuating loads and safety measures require motor support. Hybrid supercapacitors offer high power density, longer lifespan, and improved efficiency compared to traditional batteries, making them ideal for energy storage in elevator and crane systems. 
During the loading phase, excess energy from regenerative braking or other means can be stored in the hybrid supercapacitor bank. Later, when more power is needed, the stored energy can supplement the input provided by the primary power source. By combining gravity with hybrid supercapacitors, energy recovery and resource optimization can be significantly improved in various industries, leading to sustainable industrial growth.  
In the  test set-up a lift is used on a 100 m high tower (with a 87 m lifting height). The lift is designed to carry upto 1600 kg (about 21 people) and uses a 26 kW motor. The motor is coupled to a hybrid supercapacitor battery of 624V with a 5.26 kWh capacity.

The battery can deliver up to  25 kW with higher peaks.  The counterweight has a mass of a 1000 kg.  Depending on the mass of the load (vs. the counterweight) and the elevator’s direction excess energy will be absorbed by the hybrid supercapacitor battery. Alternatively, it supplies energy to the motor, reducing the energy delivered from the grid connection. The test setup aimed at measuring the energy savings. The test executes 10 up and down runs with no load, a 25%, a 75%, a 100% load and in all cases with the battery connected and disconnected. The elevator moves at 2.5 m/s. The energy savings reach about 50% in the 2 extreme cases (no load, 100% load) as was to be expected but also showing that the energy  losses  of the elevator and battery set-up are minimal.

Load Battery connected Energy used per up/down cycle (kWh) Energy savings
No load Yes 0,1048
No 0,0729 50,84%
25% yes 0,0729
No 0,101 27,11%
50% Yes 0,0788
no 0,0811 2.74%
75% Yes 0,1043
No 0,1800 42,07%
100% Yes 0,1491
No 0,2922 48,97

Finally, a fault case was tested whereby the grid connection was removed and the up-down cycle was executed 10 times. The hybrid supercapacitor battery supplied the energy with no issues. Below pictures of the set-up