Steam power plants

Steam Power Plants are critical elements of any network’s generation portfolio, but they are often punished for their inflexibility.

With increased intermittent renewables, more volatility in the electricity markets, and increasing uncertainty in future revenues, steam power plants are turning to the Thermal Battery to render their fleets more responsive to an increasingly complex grid. The Thermal Battery gives steam power plants the capability of ramping up/down as fast as a battery, increasing its peak power output and enabling operation at lower load, without being limited by the boiler.

The Thermal Battery acts like an extraction by diverting live steam from the boiler away from the turbine when compelled and discharging back into the steam water cycle when opportune. The Thermal Battery responds within seconds to any change in load, or going from charge to discharge, enabling for the plant’s participation in a myriad of power markets.

Revenue opportunities

  • Frequency Regulation/Reserve Market Participation
  • Capacity Market Bid Increases
  • Wholesale Power Price Arbitrage
  • Fast Ramping Capabilities
  • Dispatchable Steam Grid Sales

Case example

In the United States, EnergyNest is developing a 55 MWhth Thermal Battery project with a steam-cycle power plant built in the 1980’s. The retrofitting is designed to divert steam away during low-power price events, and reintroduce the steam during high-price events, enabling for a larger steam flow through the turbine, increasing its output by 4.5 MWel for up to four hours. The discharge will take place during the higher supply price hours of the day and also increases the plant’s bid capacity into the capacity market. These two revenue streams alone provide enough value to pay for the Thermal Battery installation and integration in only five years. Additional value streams like tax depreciation and environmental credits are currently under evaluation, and the newfound ability of the plant to turn down capacity will allow for upstream renewable energy to curtail for fewer hours each year.


  • Conservatively Estimated Pre-tax IRR of 20%+
  • Power Price Arbitrage representing 40% of the annual returns
  • Capacity Market Revenue Increases representing 60% of the annual returns
  • Opportunity for Frequency Regulation participation not included in assessment of returns; potential to add 10% additional
  • Opportunity for environmental credits not included in assessment of returns; potential for 25% additional
  • Opportunity for depreciation benefits not included in assessment of returns; potential for 18% additional
  • Upstream variable renewables will now curtail for fewer hours each year; currently not valued by the grid but will for certain in the near future.

Thomas Palkovich

VP Project Development

+47 9820 8384