...Lucy moves thousands of weights up and down the faces of Willis Tower and the Hancock Building. The weights ride on smooth electromagnetic rails, each weight independently latching onto cables and pulleys that in turn attach and detach to flywheels and generators, all of them orchestrated by Lucy as she responds to the ever-shifting requirements of GLA’s grid. Lucy absorbs the winds on the lake with her turbines, she feels the heat of the sun on her solar skin, and she plans and strategizes all the time. When a surfeit of sunlight or wind surges into the grid, Lucy harvests the power and winches weights high into the air. By slapping one-ton weights together like giant Lego bricks, connecting one to the next with clamps, and pushing them up the sides of the building, she hoists hundreds of tons of potential energy up into the air. Then, when demand surges, she lets precise numbers of the weighted bricks fall, generating exactly the amount of power that the grid demands, increment by increment. At the same time, she creates a constantly moving light display all up and down the skyscraper as bricks rise, fall, connect, some higher, some lower, something always moving, a living visualization of the power usage of the city.