What is Geothermal Energy and How it is Harnessed?

 

What is Geothermal Energy and How it is Harnessed?

Geothermal energy often lacks the recognition it truly deserves. In most discussions about renewable energy, the spotlight is typically on solar and wind as reliable energy sources. However, much of the truth about geothermal energy remains untold. In this short article, I aim to reintroduce geothermal energy and answer a simple yet important question: What is geothermal energy, and how is it harnessed?

What is Geothermal Energy?

Geothermal energy is one of the most reliable energy sources in the Philippines. Alongside solar, wind, hydro, and biomass, it contributes to the country’s green energy mix. The word "geothermal" comes from "geo," meaning earth, and "thermal," meaning heat. Essentially, geothermal power plants tap into the earth's heat to produce electricity.

How is Geothermal Energy Harnessed?

To harness geothermal energy, a well is drilled approximately 2 kilometers beneath the earth's surface to access underground reservoirs. From these wells, geothermal fluid—a mixture of brine and steam—is extracted.

Geothermal Power Plant Process Flow Diagram

The geothermal fluid passes through a separator vessel, which removes condensate and impurities from the steam. The purified steam flows through a series of pipelines to the power plant, while the collected condensate is reinjected into the ground to replenish the reservoirs and ensure sustainability.

Inside the power plant, the steam drives a turbine that is coupled to a generator. The turbine’s rotating motion powers the generator, producing electricity. Once used, the steam is condensed and reinjected into the ground, completing the cycle.

What Sets Geothermal Energy Apart?

One of the key advantages of geothermal energy is its ability to operate at full capacity 24/7, making it a reliable source of baseload power. Unlike solar energy, which depends on daylight, or wind energy, which can fluctuate, geothermal energy provides a stable and consistent power supply.

The Bigger Picture

While geothermal energy is a dependable and sustainable option, it cannot single-handedly meet the Philippines' energy demands. A diversified energy portfolio—combining geothermal, solar, wind, hydro, and biomass—will ultimately be the key to a sustainable future.