San Antonio Water System Invests in Resilience with Dual Purpose Microgrid

March 13, 2023
Dual purpose microgrid and natural gas generators will protect critical water production facilities during extended power outages.

San Antonio Water System (SAWS) is investing in the resiliency of its water pumping stations in Bexar County, Texas. The utility has chosen Texas-based Enchanted Rock to install natural gas generators and a dual purpose microgrid that will ensure continuity of operations during extended power outages.

Texas has been rocked in recent years by devastating power outages, including a week-long event in the wake of 2021’s Winter Storm Uri that left many in the state without electricity or water.

SAWS lost power to a key water pumping station during that storm, which led to cascading problems across the utility’s entire system.

"Water is a critical component of life, and no matter what the weather or grid conditions may be, there should be no compromise to have access to clean drinking water," said Jayesh Goyal, chief revenue officer of Enchanted Rock.

Natural gas generators to be deployed

Enchanted Rock will provide SAWS with around 70 modular natural gas generators that will be sited at 15 different water facilities in the utility’s service area. 

The system also includes technology to monitor the power grid, water equipment and weather conditions.

Enchanted Rock calls its solution a dual purpose microgrid because it is grid connected and it can operate independently in island mode. This means that the system not only provides resilience during power outages, but also it can be used to support the grid during times of peak demand.

Partnership with local energy provider

SAWS, Enchanted Rock and local energy provider CPS Energy worked in partnership on the microgrid project. Enchanted Rock will maintain the generators while CPS Energy will monitor and direct how the output will be used, proactively adjusting the generators' output based on grid conditions, equipment, and weather conditions.

As the grid power provider for SAWS, CPS Energy will use the microgrid and its generators to ensure that SAWS facilities have the necessary power to maintain operations during grid outages. Otherwise, the generators can be used to support the wider power grid during times of peak demand. 

Improved sustainability

Diesel generators have been widely used to provide backup power to critical infrastructure, including water utilities. The modular natural gas generators Enchanted Rock will install at the SAWS facilities offer the same level of resilience but are significantly quieter and have lower emissions and offer more sustainable energy than their diesel counterparts, according to Enchanted Rock.

Water utilities are increasingly turning to microgrids

SAWS is not alone when it comes to water utilities adopting microgrid technology. In 2022 the West Harris County Regional Water Authority (WHCRWA) in Texas selected Enchanted Rock to provide a 20 MW microgrid to support two critical water pump stations.

In 2020, Enchanted Rock announced that it had been selected to set up a 2.4 MW microgrid for the North Fort Bend Water Authority as well as a 30 MW microgrid for the City of Houston’s Northeast Water Purification Plant Expansion Facility.

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About the Author

Kathy Hitchens | Special Projects Editor

I work as a writer and special projects editor for Microgrid Knowledge. I have over 30 years of writing experience, working with a variety of companies in the renewable energy, electric vehicle and utility sector, as well as those in the entertainment, education, and financial industries. I have a BFA in Media Arts from the University of Arizona and a MBA from the University of Denver.

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