Modeling and Analysis of Hybrid Geothermal-Solar Energy Storage Systems in Arizona

Abstract

Intermittency, low-capacity factor, and grid instability are key factors preventing renewable energy from being cost-competitive with conventional energy resources in all locations. This is unfortunate since renewable energy has many promising environmental and sustainability benefits. Particularly, solar-geothermal hybrids (including photovoltaic and concentrated solar power) have been shown to be a favorable and auspicious combination of renewable energy sources. Integrating geothermal and solar energy is feasible since regions have high geothermal heat flow and surface radiation. The efficiency of power generation from geothermal energy is related to the resource temperature, which is why the geothermal business prioritizes geothermal resources with high temperatures. Most geothermal resources only reach temperatures of approximately 150 °C, a low- moderate temperature. The alternative is to utilize solar energy to heat geothermal fluids, which would boost the efficiency of geothermal power plants. Geothermal fluids have the potential to act as storage systems for solar energy. This ability leads to overcoming several issues in solar energy systems, including reliance on the weather and volatility. In addition, if concentrated solar powers (CSPs) are integrated into a geothermal power plant, they may be able to meet the peak power demand throughout the day, which is helpful for the lifespan of geothermal fields. In the United States, some of Arizona’s hot springs are found in the state’s southeastern section, the Clifton area, which might be harnessed to generate electricity. On the other hand, Arizona is one of the sunniest states and has enormous potential to grow in the solar industry. In this article, we discuss the possibility of developing solar and geothermal power systems in Arizona. Then, we evaluate stand-alone solar and geothermal power plants in Arizona to make a comparison between different energy storage systems. Finally, we analyze the stand-alone efficiency, hybrid efficiency, and the percentage of incremental efficiency from the literature. We use Engineering Equation Solver (EES) to analyze the system’s performance and estimate the energy cost. This model’s results will help us evaluate the designs, methods, and distinctive characteristics of creating hybrid solar-geothermal power plants in Arizona. The conclusion is that integrating geothermal and solar energy systems will boost the system efficiency and power output of both energy sources and provide a promising new avenue for research and development in Arizona State.