Earth Notes: Non-wired Electricity

Apr 24, 2019

For many years the tiny town of Punkin Center, south of Payson, Arizona, has been best known for the prominent jack-o’-lantern sign. Now it’s home to a cutting-edge alternative to traditional electrical transmission lines.  

Batteries at Punkin Center
Credit Arizona Public Service

Existing powerlines couldn’t keep up with the town’s growing demand for electricity. So, Arizona Public Service recently installed a pair of four-megawatt-hour, grid-scale batteries— instead of stringing nearly twenty miles of replacement wires over rough terrain.

Normally such batteries store excess solar power for use at peak times, provide voltage support, or serve other needs. But the Punkin Center project is unique. The primary function of the new battery array is to be a basic part of electrical grid operations. The stored power can be delivered on the twenty or thirty days in summer when existing wires can’t keep up with demand.

The non-wired system at Punkin Center costs less than half that of conventional wire installation.  And it has the capacity to soak up negatively priced energy when supplies are high—then put that power to use when supplies become short and are more expensive.

In five years, if the town’s power demand growth is less than predicted, APS can literally pick up and move the battery units somewhere more useful.

With battery prices coming down, this evolution toward more sustainable smart-grid power delivery could work at other remote sites across the Colorado Plateau in coming years—saving not just money but also an unfettered view of the landscape.