Harnessing the Earth’s core: A sustainable solution to boosting geothermal energy and ensuring uninterrupted electricity

The world is clamoring for renewable energy that reduces carbon emissions and has far less impact on the environment than fossil fuels. Achieving the Paris Agreement’s goal of being net-zero by 2050 will require a global paradigm shift that will no doubt include geothermal and solar power in the energy mix.

Harnessing the Earth’s core and the power of the sun

A sustainable solution to boosting geothermal energy and ensuring uninterrupted electricity involves the following technologies:

• Medium enthalpy geothermal power plants employ an Organic Rankine Cycle binary system that pumps organic fluids with a lower boiling point than steam through a heat exchanger to drive a turbine and generate electricity.
• Concentrated solar power (CSP) technology is a type of renewable energy that uses mirrors or lenses to concentrate sunlight onto a receiver that converts the energy into heat that is then used to power a steam turbine or heat engine to generate electricity.

Separately, these two processes have limitations. CSP is weather dependent and unreliable for peak power demand, while geothermal fields are location dependent and have short lifespans. When these are combined in a hybrid system however, they increase power generation and the longevity of geothermal resources. They also have the potential to increase the efficiency, reliability, and sustainability of power generation at a lower cost than using either technology alone.

Stillwater, the world’s first CSP-Geothermal plant

In recent years, various feasibility studies and projects have demonstrated the benefits of integrating CSP within a binary geothermal power plant. CSP-geothermal hybrid systems complement and improve each other by addressing some of the inherent limitations of each system and ultimately providing a stable and reliable base load power. These hybrid plants are being used in the United States, particularly in Nevada, Oregon, and Utah.¹

For example, Enel Green Power developed the first combined CSP geothermal plant in the United States in 2014 by integrating a new CSP plant with an existing geothermal facility. The award-winning design has set a precedent for the implementation of other hybrid plants worldwide.

Hatch is committed to developing energy self-reliance and power resilience with hybrid solutions. We are constantly looking for ways to enact positive change by reducing emissions and promoting cleaner energy generation. Find out more on how we’re responding to the energy transformation.

For more detailed information about the CSP geothermal process, see Faezeh Orojlou’s technical paper: “Using concentrated solar power technology to extend the life of geothermal resources and maintain peak power supply.”  

References

¹ U.S. National Renewable Energy Laboratory (NREL) Transforming Energy, Stillwater GeoSolar Hybrid Plant CSP Project