Hidalgo County, Texas, USA

Anemoi Energy Storage Project in Hidalgo County, Texas

Status: Under construction


According to the U.S. Energy Information Administration (EIA), in 2021, the main source of power generation in Texas was natural gas (51%), followed by wind (24.7%) and coal (13.1%).  That same year, Texas generated nearly 481,844 gigawatt-hours (GWh) of electricity, resulting in the emission of approximately 206 million metric tons of carbon dioxide (CO2), 148,244 metric tons of nitrogen oxides (NOx) and 147,939 metric tons of sulfur dioxide (SO2).

The transition to a low-carbon, and eventually zero-carbon grid, provides challenges and opportunities as increasing amounts of renewable energy are incorporated into the electric system. One of the main challenges is the intermittent nature of renewable energy sources, such as wind and solar. Grid operators must have the capability to regulate and maximize the efficient use of electricity in the grid from both baseload and intermittent sources. One of the simplest and most efficient solutions is the implementation of energy storage systems.

Battery storage systems help smooth out the delivery of intermittent resources, such as wind and solar, by storing energy and delivering it when demand increases. They also help prevent emissions by reducing the need for fossil-fuel power plants to regulate constant changes in energy supply and demand. As the energy supply mix becomes cleaner with low- and no-carbon resources, energy storage will help integrate that supply mix into the grid more easily and reliably.


The project consists of the design, construction and operation of a battery energy storage system (BESS) with a capacity of 200 megawatts of alternating current (MWAC) and two hours of duration. The main components of the project include:

  • 176 units of a manufacturer-integrated liquid cooling energy storage system;
  • 59 power conversion systems, to condition and convert power to and from the battery system;
  • an energy management system to monitor, operate and track the BESS remotely, as well as document its performance;
  • an electrical substation with a transformer to convert the electricity sent from the BESS to the grid, as well as the electricity received from the grid to be stored in the battery system.
  • A 1,100-foot transmission line to connect the project substation to the Pomelo Substation located east of the project site.

The electricity generated and products (ancillary services) enabled by the BESS will be sold in the wholesale electricity market operated by Electric Reliability Council of Texas (ERCOT).


The project will help increase energy storage capacity in the Texas grid, which will allow the system operator to manage the grid more efficiently by reducing the use of ramp-up/ramp-down fossil-fuel power generating plants, as well as energy losses resulting from mismatches in supply and demand. Likewise, it will support the transition to a greener, more sustainable grid by helping integrate electricity generated by intermittent renewable energy sources, such as solar and wind. The project is expected to store up to 118,377 MWh of energy a year. As a result, the project will displace the emission of an estimated 50,571 metric tons/year of CO2, 38 metric tons/year of NOx and 38 metric tons/year of SO2. The electricity stored and delivered annually by the BESS will be equivalent to serving up to 28,597 households.