Part 4: Lessons from Existing Storage Applications

Parts I, II and III of our examination of the Texas energy storage market review various operating technologies in the state, including compressed air energy storage, battery storage, thermal storage, and flywheels. Perhaps, more importantly, is the diverse range of applications of electric storage technology being illustrated at the utility, microgrid and community levels.

Texas has become a leading example of the economic value of storage through innovative applications such as emergency backup power, grid reinforcement, reducing transmission and distribution (T&D) costs, time-shifting usage to non-peak periods, balancing variable generation, and other ancillary services. The number and variety of projects summarized in this series is testimony to Texas’ promise of meeting future energy needs using innovative storage technologies and applications.

The storage projects discussed provide valuable experience and data to inform the future. Below are a few of the notable takeaways:

  • Experience from the Electric Reliability Council of Texas’s (ERCOT’s) fast responding regulation service (FRRS) pilot and the subsequent market implementation of pilot projects to recruit resources to keep the grid at 60 Hz show that the technical requirements can be meet with both large and small battery systems. Adequate resources can and will participate as cost and efficiencies improve and the price is right.
  • When combined with existing industrial demand response systems, the large scale storage projects in place will provide the needed load response requirements to balance the grid in peak times and to accommodate wind farm drops — a 36 MW battery and two compressed air energy storage (CAES) projects, respectively rated at 317 MW and 270 MW. Joint-ventures between storage projects and wind and solar farms will make ERCOT’s management task easier.
  • Municipally-owned utilities and cooperatives are more able to engage storage for multiple functions than are entities in the restructured market of ERCOT, and have the flexibility to experiment with different technologies, as is seen in the several projects developed by Austin Energy, CPS Energy, and Georgetown.
  • Storage projects at large end-user sites are and will continue to keep the grid peak from growing at the rate of KWh growth driven by the competitive retail market.

Texas’s success in adopting these innovative storage technologies should serve as a model to other states interested in proliferating alternative sources of energy for utility, microgrid, and community-scale applications.