A Cell Rack PSU is simply an array of power cells slaved together with a control module to store decent amounts of power. Mobile PSUs can be rolled to wherever they're needed and hooked into the grid, while static PSUs can be built to replace SMESes if the ability to rebuild them is not available for whatever reason. They are less expensive to build, but obviously store much less power; however, any standard power cell, even the low-capacity batteries found in space heaters and other small appliances, can be used in a PSU without difficulty.

To build a PSU you need enough metal to build the framework, wire to build the terminals, a PSU control board, glass to build the control terminal, and up to ten power cells.