June 28, 2023
Geothermal energy is simply heat generated within the Earth. It is a renewable resource harvested for more sustainable power generation.
The Earth's core lies nearly 2,000 miles below the surface, where temperatures rise to more than 5,000 degrees Celsius. Only a small portion of heat is generated by natural friction and gravitational pull; the majority of heat is generated by the decay of radioactive isotopes.
Unlike other alternative energy sources, geothermal energy is a low-carbon source that operates all year round, independent of weather conditions.
Geothermal energy is more than just a heat source; you can think of it like a natural battery, continuously replenished by the Earth’s core. By harnessing this heat, we can tap into a renewable energy source to fuel our homes, businesses, and cities.
Despite only meeting a very small percentage of the UK’s energy needs, the process of converting geothermal energy is quite simple. Geothermal power plants harness the Earth's heat by extracting steam or hot water from underground reservoirs. This steam then drives turbines connected to generators, producing electricity with remarkable efficiency and leaving a minimal environmental footprint.
There are three different types of geothermal reservoirs, each offering their own unique advantages:
Unlike fossil fuels, geothermal energy has a minimal environmental impact, and unlike alternative energy resources, like solar and wind power, it is not weather-dependent. Geothermal energy delivers a consistent stream of power; the Earth's internal heat serves as an infinite reservoir, ensuring a stable and dependable energy supply, making it an ideal candidate for the future of energy.
It is also a cheaper alternative to conventional energy; some studies claim it could generate savings of up to 80%. In addition to this, it will stimulate local economies by creating jobs and reducing dependence on imported fossil fuels.
Geothermal energy production is limited to areas near tectonic plate boundaries, which may cool after decades of use.
While it is a cheaper alternative to fossil fuels once the plant is built and operational, the set-up of these sites is expensive. They are also expensive to maintain.
Geothermal plants can also release hydrogen sulphide, a gas that smells like rotten eggs, alongside geothermal fluids which contain low levels of toxic materials which need to be disposed of.
Geothermal technologies currently deliver less than one per cent of the UK’s annual heat demand, meaning they are using a tiny fraction of the estimated available geothermal heat resource.
The possibility of a geothermal-powered future hinges on technological advancements in drilling, like directional and binary cycle drilling which have opened new frontiers, delving deeper into the Earth's crust.
Additionally, enhanced geothermal systems (EGS) leverage hydraulic fracturing to create permeable reservoirs, expanding the reach of geothermal power generation to unprecedented levels.
Throughout the world, nations are embracing the potential of geothermal energy and are investing in infrastructures to harness it. Beyond traditional power plants, smaller-scale geothermal systems are gaining traction, offering localised solutions for heating and cooling needs across diverse sectors.
Due to its renewability, the possibility for a geothermal-fuelled future knows no bounds. According to estimates by the International Renewable Energy Agency (IREA), its technical capacity surpasses 200 GW, with untapped resources promising up to 14,000 GW in the long term.
With exploration and investment, geothermal energy has the potential to chart a course towards a sustainable and prosperous future. However, research and development, and Government policies and incentives play a pivotal role, providing the framework for investment and innovation, while public awareness campaigns foster a culture of support and engagement.
