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Energy Storage for Fossil Fuel Energy Systems



Approach and Program Goals


The Energy Storage program will develop a comprehensive strategy to expand FE’s current portfolio of technologies and programs to include an FE Energy Storage Technology Research Program in order to continue to extract maximum economic value from the Nation’s fossil-fueled energy system assets.

High-Level Program Goals Include:

  • Leverage over a century of investment in fossil energy infrastructure
  • Extend the lifetime of existing fossil energy assets
  • Enhance the role of fossil assets as contributors to grid stability and reliability
  • Provide the Nation with a reliable fossil-based option by leveraging and extending ongoing energy storage technology development



The Current Energy Landscape

EIA, Annual Energy Outlook 2019, Reference Case
Electricity generation from selected fuels, EIA, Annual Energy Outlook 2019, Reference Case

Over the next several decades fossil-fuel plants will continue to satisfy much of our Nation’s electricity demand. As variable renewable energy penetration increases, energy storage at the generation site will be essential to a resilient and flexible electricity network. NETL’s Energy Storage program as a part of the Crosscutting portfolio aims to address these needs and challenges.

Looking forward to additions and retirements on the grid, fossil-fueled plants will continue to be added through 2050 and play a major role in generation. Due to the inherent challenges between intermittent and baseload power systems, energy storage is integral to guaranteeing a seamless transition between systems. Energy Storage will enable fossil-based systems to be more flexible and retain longer lifetimes of components, making the system more efficient and environmentally friendly.

Energy Storage in Fossil Applications Offer:

  • Improved plant economics
  • Efficiency and environmental performance
  • Reduced maintenance costs
  • Responsive to system demands for flexible operation
  • Extend the lifetime of the Nation’s fossil energy assets



US Coal fleet wtd avg capactity factor %
Capacity factors for utility scale generators primarily using fossil fuels (coal plants shown), EIA, December 2019, Electric Power Monthly

Today’s Challenges

  • Develop a set of cost-competitive storage technologies that enable the economic use of our Nation’s underutilized plant capacity
  • Predict with certainty – the changes to today’s energy environment when calculating program specific economic and environmental benefits
  • Integration of storage solutions with a broad and diverse set of existing plants – each uniquely designed with characteristics that enable operation at high efficiency and low cost

Current State

Today’s fleet of existing coal plants is operating at ~50% capacity. Energy storage provides the opportunity to take advantage of this underutilized capacity. Other projects, such as Coal FIRST, are also working to make the underutilized capacity available for flexible and resilient power.

Current Projects at NETL:

  • EPRI: The Electric Power Research Institute (EPRI) is testing a pilot-scale concrete thermal energy storage system to demonstrate the energy storage potential of the technology when applied to coal-fired power units.
  • Lehigh University: The team at Leigh is developing an optimized prototype of a solid media thermal energy storage concept for thermal management applications in coal-fired power plants.
  • West Virginia University Research Corporation: WVU will evaluate the transient response to various system concepts that minimize the levelized cost of electricity of thermal, chemical, mechanical, and electro-chemical storage technologies.



Technology Landscape

technolgy Landscape
Expansive list of various forms of energy storage applicable to fossil energy, but not necessarily fully inclusive. January 2020.



Energy Storage for Fossil Energy Benefits:

More Reliable and Affordable Energy Supply:

  • Reliability in a changing grid – storage technology enables seamless transition to accommodate continued growth of intermittent renewable power and expanded use of electrified transportation
  • More secure supply − increased ability to keep the grid running in times of cybersecurity threats and regional environmental disaster recovery
  • Reduced customer cost − leverage value of energy supply investments for energy providers

Stronger Energy Infrastructure:

  • More flexible electricity grid − quickly accommodates unexpected plant shutdowns and turndowns, easing transitions between intermittent power and base-load systems
  • Improved asset management − reduced turn-down and cycling increases equipment lifetimes and avoids pre-mature local & regional socio-economic disruptions
  • Efficiently satisfy new markets − stored energy can be made available to affordably satisfy energy demands of new ancillary services (e.g., ramping, load following, black starts)

Cleaner Environment:

  • Cleaner electricity supply − realized benefit of optimal environment footprint of base-load power plants with fewer new site development demands and lower carbon emissions



rfi pie chart
RFI analysis breakdown from December 2019 shown.

Request For Information (RFI) Analysis

Response Overview:

NETL’s Crosscutting program solicited input from entities in the energy storage field through the request for information (RFI). A total of 23 individual responses were received from 21 different entities in December 2019. Responses included academia, new entrants into power, suppliers, and more. The RFI aimed to identify and assess technology and knowledge gaps in energy storage. It also sought to identify advances in energy storage technology options to enable economic plant operation when responding to reduced cold/warm start time, increased ramp rate, reduced minimum plant load, and increased plant thermal efficiency.








Technology area contact:

Briggs White

HQ Program Manager:

Bhima Sastri