Modeling Reservoir Circulation and Economic Performance of the Neal Hot Springs Geothermal Power Plant (Oregon, U.S.): An Integrated Case Study. (November 2017)

• Record Type: Journal Article
• Authors: Weijermars, Ruud; Zuo, Lihua; Warren, Ian
• Is Part Of: Geothermics. Volume 70(2017:Nov.)
• Page Start: 155
• Page End: 172
• Publication Date: 2017-11
• Subjects: Geothermal energy -- Reservoir circulation -- Economic model -- Neal Hot Springs; Hydrogeology -- Periodicals; Geothermal resources -- Periodicals; Énergie géothermique -- Périodiques; GEOTHERMAL ENGINEERING; GEOTHERMAL ENERGY; GEOTHERMAL EXPLORATION; Geothermal resources; Hydrogeology; Periodicals; Electronic journals; 621.44
• DOI: 10.1016/j.geothermics.2017.04.011
• Languages: English
• ISSNs: 0375-6505

Abstract

Highlights: NHS geothermal reservoir flow visualized using novel streamline simulation. History matching tracer tests suggest main reservoir is in 10 cm wide crack. Existence of a deep-seated heat source postulated. NHS geothermal project profitable thanks to subsidiary grants. Abstract: We review the key factors that facilitated the successful development of a geothermal reservoir at Neal Hot Springs (NHS), Oregon, by a private company. The NHS geothermal field development plan, financing tools, and fluid circulation model provide a template for the development time, financing and well rates required to sustain geothermal power generation in similar setups elsewhere. The early economic performance and life-cycle analysis are specified using company data, applying a financial evaluation tool developed by the National Renewable Energy Laboratory (NREL). The Neal Hot Springs geothermal project was enabled by a combination of financing sources: U.S. federal loan guarantee and cash grant, state tax credit and private equity. Flow patterns in the NHS geothermal reservoir are visualized using a novel streamline simulation tool applying known well rates and benchmarking the residence time of re-injected brine based on tracer tests performed by the company. Temperature of produced brine has stayed remarkably constant over the first years of NHS plant operations, which we ascribe to advection of heat by an upwelling far-field flow beneath the plant's production wells.