Solar-Augment Potential

The data are the results of a joint study between NREL and the Electric Power Research Institute (EPRI) to integrate solar thermal energy into existing or planned coal-fired and natural gas combined cycle (NGCC) plants. The study ranked the solar-augment potential for fossil plants throughout 22 states in the southeast, southwest, northwest and central United States.

Each generating unit was ranked in six categories: the age of the fossil plant, the average capacity factor of the fossil plant, the solar resource available at the plant site, the amount of available land surrounding the existing plant, the topography of that land, and the solar-use efficiency expected if the plant were augmented with a solar field. Plants not meeting a minimum threshold in any of these categories, that did not have capacity for solar steam, or for which data were insufficient, were scored Not Considered. Others were given a qualitative score of Excellent, Good, or Fair. Facilities were modeled by individual unit, but the scores were aggregated for the entire plant site.

Separate analysis was performed for parabolic trough and power tower technologies due to the difference in the steam temperatures that each can generate. The qualitative ranking shown in the Solar Prospector are based on the use of power towers; although both power tower and parabolic trough augment potential are provided for each site when queried. Power towers offer more capacity and higher quality integration due to the greater steam temperatures that can be achieved; however, the possibility of height restrictions at the sites were not considered.

In many cases, solar-augment of existing fossil power plants offers a lower cost and lower risk alternative to stand-alone solar plant construction. Based on this and prior EPRI analyses, the best economics occur with the offset of duct firing when augmenting NGCC plants; while the greatest reduction in air pollutants is achieved through the augment of coal plants.

Users seeking further information should visit the NREL report:
Solar-Augment Potential of U.S. Fossil-Fired Power Plants

Stakeholders seeking more information regarding solar augment research activities are advised to access the EPRI
Renewable Energy Program. They may also download a Summary Report of past EPRI study results.

NOTE: Locations displayed may differ from locations used in the study. Siting locations used for the analysis were obtained from licensed SNL and Ventyx datasets. Licensing agreements do not allow the display of SNL or Ventyx site locations. The electric generating plant locations for display were obtained using one of the following resources: EPA eGRIDpublic data, Carma.org, or by geocoding search results for plants not available from eGRID or Carma.org.