What Is The World’S Production Of Geothermal Energy?

Geothermal energy is thermal energy generated and stored within the Earth. It is a renewable energy source that utilizes the natural heat of the earth’s interior to produce steam and hot water. With increasing focus on transitioning to clean and sustainable energy sources, geothermal energy is an attractive option since it provides constant and reliable baseload power.

As countries work to reduce greenhouse gas emissions and limit dependence on fossil fuels, renewable energy sources like geothermal play an important role. Geothermal energy has a small carbon footprint and minimal environmental impact compared to conventional energy sources. This makes it a promising clean energy solution.

This article will examine the current global production of geothermal energy. It will look at installed geothermal power capacity worldwide and direct uses of geothermal resources. The future outlook for the industry and the economics of geothermal energy will also be discussed.

Global Geothermal Energy Production

The world produced about 95 terawatt hours (TWh)of geothermal power in 2021. This amounts to about 0.3% of total global electricity production. The installed generation capacity was about 16 gigawatts (GW) in 2021.

The top 5 countries for geothermal electricity production are the United States, Indonesia, Philippines, Turkey, and New Zealand. Together they account for about 70% of worldwide geothermal generation.

Global geothermal production has grown at an average annual rate of 3% in recent years. Growth is expected to accelerate in the coming decades as technology improves and more countries tap their geothermal potential. The geothermal industry expects capacity to double to 32 GW by 2030.

Geothermal Power Plants

There are three main types of geothermal power plants: dry steam, flash steam, and binary cycle. Dry steam plants are the simplest and oldest design. They utilize steam from geothermal reservoirs to directly turn electricity-generating turbines. Flash steam plants take high pressure hot water, usually above 360°F, and convert it to steam to drive turbine generators. Binary cycle plants differ in that the hot water from the ground heats and vaporizes a separate working fluid, which has a much lower boiling point than water. The vapor from this fluid then drives the turbines.

The pros of geothermal power plants are that they provide constant base load power unaffected by changing weather and climate patterns. They have low emissions and a small footprint compared to conventional power plants. However, geothermal plants can only be built in geologically active areas with access to hydrothermal resources. High upfront capital costs for drilling and fluid pipelines are a barrier. Power generation potential at a site can decline over time as the geothermal field gets depleted.

Direct Uses of Geothermal Energy

In addition to generating electricity, geothermal resources provide direct heating and cooling for homes, buildings, hot springs, greenhouses, fish farming and other applications. This accounts for a significant proportion of global geothermal energy use.

Geothermal district heating systems distribute hot water from a geothermal reservoir to multiple buildings for space heating, domestic hot water and even snow melting. These systems are located near geothermal fields that provide a reliable and clean source of heat.

Geothermal heat pumps leverage shallow geothermal resources in the upper 10 feet of the Earth’s surface to provide heating and cooling for homes and buildings. Underground piping transfers heat between the Earth and the building for efficient temperature control.

Low temperature geothermal resources allow geothermal heating in greenhouses to extend growing seasons and increase crop yields. The heat warms soil and air temperatures, provides humidity control and CO2 enrichment while minimizing disease and pests.

Geothermal heating is also used to warm fish farm pools and hatchery water. Aquaculture applications can substantially increase fish growth rates in colder climates.

Some industrial processes utilize geothermal heating for food dehydration, gold mining and laundering. Geothermal energy directly replaces the need for grid electricity or fossil fuels in these operations.

Future Outlook

The future of geothermal energy looks promising, with projections for steady growth as technology improves and more capacity comes online. Geothermal is expected to play an increasingly important role in the global renewable energy mix.

One area with significant potential is enhanced geothermal systems (EGS). These systems can tap into hot dry rock reservoirs deep underground that lack natural permeability and fluid saturation. By drilling injection and production wells, engineers can pump water through the rock at high pressure to create fractures and improve connectivity, allowing geothermal fluids to be circulated through a closed loop system to generate electricity. EGS technology is still in the demonstration phase but could unlock a vast amount of geothermal resources previously unreachable with conventional methods.

Advances in geoscience, drilling techniques, power plant design, and computer simulations will also help drive growth by making geothermal projects cheaper and more efficient. New binary power plants can operate with lower temperature reservoirs down to 165–180°F. Innovations like coproduced electricity and minerals extraction and integrated storage systems maximize the value of a geothermal resource.

With supportive policies, research, and investment in the sector, the geothermal industry is poised to scale up exponentially, providing abundant flexible baseload power with a small land footprint and low carbon emissions.

Challenges

While geothermal energy has many benefits, developing geothermal power plants comes with some challenges.

One major challenge is the high upfront costs required for geothermal development. Drilling exploratory wells and constructing the power plant and supporting infrastructure requires significant capital investment before any electricity can be generated and sold.

Finding suitable locations with adequate geothermal resources is also a challenge. Not all areas have accessible hot water or steam reservoirs at shallow enough depths to be economical to develop. This geographic limitation restricts geothermal development to certain regions.

Managing emissions from geothermal plants can also be an issue. While geothermal energy is considered low-emission compared to fossil fuels, geothermal reservoirs still contain gases like carbon dioxide, hydrogen sulfide, ammonia, and methane that are released in the process. Proper monitoring and mitigation techniques are needed to minimize the environmental impact.

Environmental Impacts

Geothermal energy has several environmental impacts that should be considered. Three main areas of concern are land use, emissions, and induced seismicity.

Geothermal plants require large areas of land for the wells, pipelines, power plant and supporting infrastructure. This can lead to land subsidence as underground fluids are extracted. Careful monitoring and management is required to minimize surface disturbances.

There are low emissions associated with geothermal plants since no fuel is burned. However, geothermal reservoirs contain gases like carbon dioxide, hydrogen sulfide and ammonia that can be released into the atmosphere. New technologies are being developed to reinject these gases back underground.

Extracting fluids from underground can cause small earthquakes known as induced seismicity. These are generally low on the magnitude scale and cause little damage. But larger earthquakes have been linked to wastewater injection in some locations. Seismic risk needs to be evaluated thoroughly before projects begin.

Economics

The economics of geothermal energy production vary widely based on the resource quality, depth, and location. Drilling geothermal wells is expensive, with costs often exceeding $1 million per well. However, once a well is drilled, the marginal cost of energy production is low compared to fossil fuels.

Geothermal is cost competitive with natural gas and coal for power generation. The levelized cost of energy (LCOE) for geothermal power ranges from $0.04 to $0.107 per kWh, compared to $0.045 to $0.15 for natural gas and $0.065 to $0.15 for coal.

Many governments provide tax credits, feed-in tariffs, renewable portfolio standards and other incentives to encourage geothermal development and make it more cost competitive. The upfront capital costs for geothermal remain higher than conventional options, so incentives help attract investment.

Direct use geothermal applications like heating and aquaculture can also be economical. Geothermal heat pumps can provide heating and cooling at anywhere from 25% to 70% lower cost than conventional HVAC systems. Overall, geothermal energy provides cost-effective, reliable baseload and renewable power generation and heating.

Major Companies

Some of the leading geothermal developers and operators include:

• Ormat Technologies – Based in the United States, Ormat is a major geothermal company involved in geothermal power plant development, electricity production, and equipment manufacturing. They have projects worldwide.
• Enel Green Power – Headquartered in Italy, Enel is a large multinational utility company and a leading geothermal power producer. They own and operate geothermal plants in Italy, the United States, Chile, Iceland, and elsewhere.
• KenGen – Kenya Electricity Generating Company (KenGen) is Kenya’s largest power producer and a major geothermal developer in East Africa. They operate multiple geothermal plants in Kenya.
• Toshiba – The Japanese conglomerate manufactures geothermal turbines and equipment and has been involved in geothermal plant construction worldwide for decades.
• Fuji Electric – Another major Japanese company supplying geothermal power plant components and equipment globally.

There are various other significant companies involved in geothermal project development, drilling, construction, operation, and equipment manufacturing around the world.

Conclusion

In summary, geothermal energy production plays a small but growing role in the global renewable energy landscape. While geothermal accounts for less than 1% of total worldwide energy production, its usage is expanding each year. Geothermal power plants and direct heating applications are becoming more widespread as technology improves and demand for clean energy increases.

Geothermal’s advantages as a stable, renewable baseload resource make it an important part of diversifying the world’s energy supply. Tapping the earth’s natural heat can provide carbon-free electricity and heating with minimal environmental impact. Despite some economic and technical hurdles, geothermal energy will likely continue seeing increased global investment and capacity as countries seek to reduce their dependence on fossil fuels and mitigate climate change.