Dynamic simulation, control, and performance evaluation of a synergistic solar and natural gas hybrid power plant

Journal Article · 26 October 2018 · Energy Conversion and Management

DOI: https://doi.org/10.1016/j.enconman.2018.10.054 · OSTI ID:1613454

Rashid, Khalid ^[1]; Safdarnejad, Seyed Mostafa  ^[2]; Powell, Kody M. ^[2]

---

1. Univ. of Utah, Salt Lake City, UT (United States); DOE/OSTI
2. Univ. of Utah, Salt Lake City, UT (United States)

Solar power is considered among the leading renewable energy technologies. Abundant supply, flexibility of installation, and decreasing cost makes it an interesting renewable energy resource. However, there are challenges associated with the reliability of solar power due to its intermittent nature. This work demonstrates the synergies that exist in integrated hybrid systems, where a dispatchable fuel is used in conjunction with concentrated solar power. In this simulation-based study, a parabolic trough solar concentrator is used to collect solar energy. The heat collected from the solar field is used to generate steam in a Rankine cycle. The system also utilizes natural gas combustion in the steam generator to provide supplemental steam when the solar intensity is reduced due to cloud cover or at night. Natural gas is also used for superheating the steam, which allows the system to produce higher temperatures and achieve increased thermodynamic cycle efficiencies. This flexible design produces 100 MW at nominal conditions, while it is capable of producing a maximum of 140 MW when sufficient solar energy is available. The novel contributions of this work include a complete, systems-level, dynamic model of a hybrid solar plant. The model is complete with a control system that smoothly transitions the plant from pure natural gas mode at night to solar hybrid mode during the day. It evaluates innovative design features such as flexible fuel operation, steam superheating to boost efficiency, and preheating by solar or waste heat. Furthermore, this work demonstrates that by hybridizing a solar system with a dispatchable energy source, both the reliability and efficiency of the solar power production are increased. The annual solar-to-electric efficiency increases from 15.2% to 26.13% with hybridization, which indicates that utilization of the solar energy is effectively increased.

• Research Organization: Univ. of Utah, Salt Lake City, UT (United States); University of Utah, Salt Lake City, UT (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Advanced Manufacturing Office
• Grant/Contract Number: EE0007712
• OSTI ID: 1613454
• Journal Information: Energy Conversion and Management, Journal Name: Energy Conversion and Management Vol. 179; ISSN 0196-8904
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English