Preface

Geothermal energy is the heat that comes from the inner layers of the Earth. This heat can be used directly in the production processes such as heating buildings, aquaculture, farming, and so on, or indirectly to produce electricity from the water steam that comes from deep (1000–3000 m) geothermal wells. The source of geothermal energy is mainly attributed to the natural movement of oceanic and continental tectonic plates, which when colliding or separating from geologically active regions in which the phenomena of plate subduction or divergent plates occur causes hydrothermalism. Therefore, a geothermal system is made up of three main elements: a heat source, a reservoir, and a fluid, which is the medium that transfers the heat. The heat source can be either a magmatic intrusion at a very high temperature (> 600°C) or a reservoir.

Within the framework of the fight against climate change, geothermal energy is becoming increasingly important among renewable energy sources due to its mature technology, efficiency, and sustainability. In addition, its gas emissions are mainly water steam, reducing the negative impact on our planet. However, only 15% of the world's known geothermal reserves are exploited for global electricity production, which constitutes a very small fraction of the immense amount of energy available on Earth. Today, many countries have taken advantage of their geothermal resources. The United States and the Philippines are the largest producers of electricity from geothermal energy.

A geothermal power plant has several advantages, including reliability, independence and the fact that it is relatively inexhaustible, emits few pollutants, uses smaller land compared with solar energy, and contributes to the development of rural areas.

Recent scientific studies related to the development of improved exploration and exploitation techniques for new generations of geothermal systems show that, in the medium term, geothermal power generation will become a key element in the energy mix. Not only as a commitment to the use of renewable energies, but also as a commitment to technological development and the creation of economic activity and, therefore, employment.

Geothermal energy is an energy source with great potential. The installation of renewable energies can lead to greater performance, efficiency, and results. As such, this book provides four representative case studies from Africa, Asia, Europe, and America, highlighting the social, economic, and environmental challenges these countries have addressed to developing geothermal energy and using geothermal heat to ensure the sustainability of the resource. It also discusses the different aspects of

geothermal energy, including its social repercussions and effects on the environment, as well as public policies and management for better regulation of planning and environmental protection.

## **Zayre Ivonne González Acevedo**

Geology Department, Center for Scientific Research and Higher Education at Ensenada (CICESE), Baja California, Mexico

## **Marco Antonio García Zarate**

**1**

Section 1

Introduction

Applied Physics Department, Center for Scientific Research and Higher Education at Ensenada (CICESE), Baja California, Mexico

Section 1 Introduction

## **Chapter 1**

## Introductory Chapter: Geothermal Energy – Challenges and Improvements

*Zayre Ivonne González Acevedo and Marco Antonio García Zarate*

## **1. Introduction**

#### **1.1 Outline**

In recent years, the issue of energy production has been in the international debate. The discussion has focused on the generation of agreements and actions for the care of the environment, due to the negative impacts that the energy industry, mainly based on fossil fuels, has generated on the planet [1, 2].

The use of natural resources in a more responsible and comprehensive manner has become more relevant. The energy crisis and climate change have pointed to the development of technologies that allow the use of alternative energies with higher performance, efficiency, and less environmental impact. Hence, geothermal energy plays an important role to be used as an alternative energy source, which contributes to the achievement of the Sustainable Development Goals [3]. For example, SDG 7, on affordable, reliable, sustainable, and modern energy for all, SDG 13, on climate action and the Paris Agreement [4]. Being recognized as an ally to solve part of the problem of climate change and distribute electricity at low economic, social, and environmental cost [5].

Among the alternative energies, geothermal energy is the heat energy generated in the interior of the Earth. Under favorable conditions, a small proportion of this energy can be extracted and used by humanity. A geothermal system is the combination of the following elements: a heat source, a fluid that transfers heat, porous and permeable rocks that allow the accumulation of the hot fluid, and impermeable rocks that function as a sealing layer to prevent or reduce the migration of the hot fluid to the surface. The deeper it is the fluid, the higher is its temperature, and according to its enthalpy, it has the capacity to provide direct uses or to generate electricity [6–8].

Geothermal resources have been identified in almost 90 countries, with a record of geothermal utilization in more than 70 countries. As of 2010, electricity from geothermal energy is produced in 24 countries. Nearly 40 countries worldwide are considered to have sufficient geothermal potential that could meet their total electricity demand with geothermal energy, for example, Costa Rica, Ecuador, Guatemala, Indonesia, Iceland, Mozambique, Peru, and the Philippines. While Iceland and El Salvador have the highest share of geothermal energy in their country's energy mix, generating about 25% of their electricity from geothermal resources. The United States and the Philippines have the largest installed capacity of geothermal power plants: approximately 3000 MW and 1900 MW, respectively [9].

## **2. Advantages**

The great advantage of the geothermal resource is that its transformation into electricity can be done independently of the weather and a schedule. As is the case of wind and solar energy, playing an important role since it is available 24 hours a day, 365 days a year, allowing continuously feed to the geothermal power plants, which can act as the economic base of a region [10]. In addition to requiring, less land per megawatt produced, compared with solar and wind energy.

This energy resource has many advantages over other alternative energies when Life Cycle is considered in the analysis, such as competitive heat prices, continuous source of energy, and low environmental impacts. Furthermore, the additional valorization of geothermal water through its use for low-temperature heating and the recovery of mineral resources are ways to provide additional benefits to the local communities and/or the developer, in a sustainable environment in the exploitation of the direct and indirect uses of the geothermal resource [11]. To achieve this, a clear energy policy is needed in the countries, between the developer, government, and communities. The lack of commitment and enthusiasm of governments weakens the potential growth of the sector to be developed by private sector investment or foreign investors, to activate the production and improve the productivity of geothermal energy [12].

## **3. Challenges**

One of the challenges of geothermal energy is that it is closely linked to the geological structures present in active volcanic areas, in areas with geological faults and areas with seismic activity, which represents the uniqueness of the resource. Its extraction is a challenge, which signifies the need to improve exploration and exploitation techniques to access deep resources and avoid negative impacts on the environment. However, due to its nature, it has several opportunities for technological development and productive processes for human development with direct uses of geothermal heat or geothermal power plants [13].

Despite that, geothermal energy is an alternative source of electricity, it is sometimes considered as a renewable energy (when extraction does not exceed recharge) [14], a sustainable energy (when production rates are maintained for more than 40 years) [15], and a clean energy (when CO2 concentrations emitted are below the local limits) [16]. However, it can cause negative impacts on the environment, which sometimes trigger social conflicts.

Nowadays, it is known that environmental conflicts caused by the execution of geothermal projects introduce new variables between the developer, the government, and the communities [17]. Therefore, it is important to solve conflicts related to this natural resource. Through mediation between key actors, or by proposing management strategies for geothermal projects, which need a high level of acceptance by the inhabitants of the surrounding area, being the local factor crucial to minimize the socioeconomic impact and promote social acceptance.

*Introductory Chapter: Geothermal Energy – Challenges and Improvements DOI: http://dx.doi.org/10.5772/intechopen.109190*

## **Author details**

Zayre Ivonne González Acevedo\* and Marco Antonio García Zarate Center for Scientific Research and Higher Education at Ensenada (CICESE), Baja California, Mexico

\*Address all correspondence to: zgonzale@cicese.mx

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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*Introductory Chapter: Geothermal Energy – Challenges and Improvements DOI: http://dx.doi.org/10.5772/intechopen.109190*

In: Green Technologies to Improve the Environment on Earth. London, UK: IntechOpen; 2018

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Section 2
