Abstract
Abstract Geothermal power plants have typically been operated as baseload plants. The recent expansion of wind and solar power generation creates a potential opportunity to increase the value of geothermal generation through flexible operations. In recent years, California’s wholesale electricity markets have exhibited frequent, short-term periods of negative pricing, indicating that additional flexibility would be valued in the market. Here, we examine local nodal hourly price records at all geothermal plants located in the western United States. We describe how the frequency and temporal characteristics of negative pricing episodes have changed over recent years. Based on these price series, we calculate the value of multiple strategies of flexible operations. Additionally, we use the estimates of future prices, developed through a capacity-expansion model and a dispatch model, to explore how the value of such flexible operations might change along with further penetration of variable renewable power sources. Based on the historical pricing records, we find that simple curtailment of operations during negative pricing episodes could increase the average energy value by 1–2 $/MWh and that allowing for increased production during limited high-priced hours, in addition to curtailment during negative priced hours, could potentially double the increase in value (up to 4 $/MWh). The forward-looking simulations indicate reduced values of flexibility from geothermal power despite higher penetrations of variable renewable energy. This result highlights the possibility that increasing flexibility options throughout the system may counteract the influence of increased variable renewable energy deployment.
Highlights
In most cases, geothermal power plants have historically been operated as baseload resources; in other words, they produce constant power at all times
We aim to provide results that are useful for early-stage guidance in the assessment of new strategies and technologies that allow for flexible operations
We look retrospectively at local, wholesale electricity pricing patterns near all geothermal plants in the U.S Second, we use a price series from a capacity-expansion and a dispatch model to evaluate how the value of flexible geothermal operations may be enhanced in the future with greater penetration of wind and solar generation
Summary
Geothermal power plants have historically been operated as baseload resources; in other words, they produce constant power at all times. The recent increases in variable generation sources, such as wind and solar, prompt the question: Could geothermal generation provide greater value to electricity markets by employing strategies that allow more flexible operations? We present an assessment of the value of flexibility across U.S geothermal plants. We aim to provide results that are useful for early-stage guidance in the assessment of new strategies and technologies that allow for flexible operations. This paper focuses on the existing U.S geothermal electric power plant fleet and some context is useful. The U.S generates more electricity from geothermal sources than any other country [1]. In 2018, the U.S generated ∼17 TWh of electricity from geothermal sources, which is about one-fourth of the amount of electricity generated from utility-scale solar power in the same year [2].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
