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Hybridizing a geothermal power plant with concentrating solar power and thermal storage to increase power generation and dispatchability

Journal Article · · Applied Energy
 [1];  [2];  [3];  [3];  [3];  [1];  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Coso Operating Company, Olancha, CA (United States)
  3. Hyperlight Energy, Ltd., San Diego, CA (United States)

Geothermal power plants often deploy less than their full power capacity due to declining geothermal resources. Integrating heat from a concentrating solar power (CSP) collector field increases the power output at low cost. This article considers five methods of solar heat addition in a double-flash geothermal plant. The most promising solution converts solar heat into electrical work with an efficiency of 24.3%. The economic feasibility and optimal sizing of the solar field and thermal stores are evaluated. A hybrid plant that increases power generation from 22 to 24 MWe has a Levelized Cost of Electricity (LCOE) of 0.07 +/- 0.01 $/kWhe. Adding three hours of storage increases the LCOE to 0.08 +/- 0.01 $/kWhe. Photovoltaic systems are considered to be a low-cost renewable technology, but an equivalent photovoltaic system with battery storage costs 0.15 +/- 0.07 $/kWhe due to the high cost and replacement rate of batteries compared to thermal storage. The hybrid plant also has a lower LCOE than a conventional CSP plant. If the dispatchability that thermal storage provides is rewarded with higher electricity prices, calculations indicate storage becomes an attractive investment when discharged power receives 1.75 times the typical price of electricity.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Geothermal Technologies Office (EE-4G)
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1462472
Report Number(s):
NREL/JA--5500-70894
Journal Information:
Applied Energy, Journal Name: Applied Energy Journal Issue: C Vol. 228; ISSN 0306-2619
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

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Cited By (1)

Streamlining the Power Generation Profile of Concentrating Solar Power Plants journal January 2019