Granite Wins $31M Contract for California’s Willow Rock Energy Storage Project — Granite Construction Incorporated

Event summary

Granite awarded a $31 million early works grading package by Hydrostor for the Willow Rock Energy Storage Center in Kern County, California.
The project involves constructing site infrastructure for a 500 MW Advanced Compressed Air Energy Storage (A-CAES) facility capable of powering over 400,000 homes for eight hours.
Granite’s scope includes grading work, road improvements, stormwater basins, and laydown areas for subsurface mining materials.
The early works phase began in July 2026 and is planned to conclude in March 2027.

The big picture

This contract aligns with Granite’s strategy of expanding specialized private-sector work, particularly in the growing energy storage sector. The Willow Rock project is part of California’s push to enhance grid reliability through advanced energy storage solutions, reflecting broader industry trends toward large-scale renewable energy integration.

What we're watching

Project Execution: How Granite’s ability to manage complex subsurface work will impact the project timeline and budget.
Market Positioning: Whether this contract signals a broader shift in Granite’s focus toward specialized private-sector energy projects.
Regulatory Dynamics: The pace at which California’s energy storage mandates will drive demand for similar projects.