Silicon Valley Photovoltaics Society monthly meeting (SVPVS)

EPRI recently completed a study to identify and evaluate the technical and economic viability of solar augmentation options for both coal and natural gas steam cycle plant designs. This was the first study to comprehensively evaluate several solar technologies and integration options for a range of fossil technologies.

"Solar Thermal Hybrid Applications", Cara Libby, EPRI.

As fossil fuel prices rise and emission allowances are implemented, solar augmented steam cycles might be an attractive option for energy companies. The system utilizes steam generated by a solar field in a conventional coal -powered steam cycle, offsetting some of the fossil fuel required to generate power. Many energy companies are interested in adding solar power to their generating mix, but today most solar applications are not cost-competitive with other power generating options. Solar augmentation potentially is the lowest cost option for adding solar power to the generation fleet. The highest intensity solar energy typically is within a few hours of peak summer loads, making it a particularly attractive renewable option.
The Electric Power Research Institute (EPRI) recently completed a study to identify and evaluate the technical and economic viability of solar augmentation options for both coal and natural gas steam cycle plant designs. This was the first study to comprehensively evaluate several solar technologies and integration options for a range of fossil technologies. The study consisted of a broad conceptual design analysis and four detailed plant case studies. Detailed heat and mass balance models were developed to screen and evaluate various solar steam integration schemes. Development guidelines were prepared for two coal plants located in New Mexico and North Carolina and two natural gas combined cycle plants in Nevada and Arizona. The guidelines include a detailed analysis of siting requirements, plant cycling limitations, plant controls, reliability considerations, operations and maintenance requirements, regulatory and environmental permits, and construction and commissioning schedules. An economic model was developed to estimate the benefit-cost of adding a solar field to an existing plant.

An advisory committee of experts from the U.S. National Renewable Energy Laboratory and Sandia National Laboratories provided valuable technical expertise throughout the project. The results and insights gained in the study provide expanded options to plant owners who wish to leverage existing plant assets, reduce their carbon footprint, and gain valuable experience with solar thermal electric systems. Compared to standalone solar thermal plants, the economics of the integrated solar steam cycle applications were favorable.