4.3 Energy shifting; storing excess renewable generation for later use

The core use case for co-located storage

Energy shifting is the most straightforward application of utility-scale BESS and the dominant use case for projects co-located with solar generation. Solar arrays generate maximum power during midday hours. Demand peaks in the evening. The gap between those two periods is the problem BESS was built to solve.

A solar-plus-storage project captures the excess solar generation that would otherwise be curtailed — wasted because there is more supply than demand — and shifts it to the evening peak window when it has both grid reliability value and market value. The BESS essentially extends the useful generation window of the solar asset past sunset.

From a construction perspective, energy shifting drives the co-location layout decisions that define what the field crew is building. The battery containers, PCS skids, and associated MV infrastructure sit alongside the solar inverter stations and share a common interconnection. The sequencing of civil, electrical, and commissioning work reflects that integration. Understanding the use case helps you understand why the site is laid out the way it is.