Hydrogen, Batteries and Fuel Cells

Bengt Sundén

• Publisher: Academic Press
• Year: 2019
• ISBN:
  9780128169513
• Topic: Tecnología e ingeniería
• Subtopic: Recursos de energía renovable

Hydrogen, Batteries and Fuel Cells provides the science necessary to understand these important areas, considering theory and practice, practical problem-solving, descriptions of bottlenecks, and future energy system applications. The title covers hydrogen as an energy carrier, including its production and storage; the application and analysis of electrochemical devices, such as batteries, fuel cells and electrolyzers; and the modeling and thermal management of momentum, heat, mass and charge transport phenomena. This book offers fundamental and integrated coverage on these topics that is critical to the development of future energy systems.

• Combines coverage of hydrogen, batteries and fuel cells in the context of future energy systems
• Provides the fundamental science needed to understand future energy systems in theory and practice
• Gives examples of problems and solutions in the use of hydrogen, batteries and fuel cells
• Considers basic issues in understanding hydrogen and electrochemical devices
• Describes methods for modeling and thermal management in future energy systems

Chapter 1

Introduction and background

Abstract

This chapter gives a brief background on various energy sources, hydrogen and electrochemical devices. Concepts of batteries, fuel cells and electrolyzers are presented. Finally a principle outline of how renewable energy sources and hydrogen can be integrated in the energy system.

Keywords

Renewable energy resources; Hydrogen; Electrochemical devices; Integrated energy systems

Electricity is an energy carrier which makes life easier by providing light, heat, hot water, cold food, computers and TVs etc. Energy sources are converted to electricity as it is easier to use and move. Currently, a great portion of the production of electric power is coming from so-called fossil fuels and only a smaller portion from renewable energy sources. For transportation also huge amounts of fossil fuels are used. The increased global concern for the high greenhouse gas emissions by fossil fuels and its effect on the global warming and the environment have demanded search for alternative systems for electricity production and alternative powertrains for transportation.

1.1. Primary energy sources - fossil fuels

The global primary energy sources for stationary power generation and for transportation are fossil fuels. Currently fossil-based fuels like oil, coal and natural gas, provide approximately 85 % of all energy being used worldwide. The current exploration of shale oil and shale gas also concerns fossil fuels. These resources are being depleted and cannot be replaced in any reasonable time period, i.e., they are non-renewable. Besides being finite, the energy production from fossil fuels results in by-products from combustion like particles and harmful gases like CO₂ and NO_x. It is well known that these emissions affect the environment, our health and cause changes of the climate. Fossil fuels also contribute to sulfur emission to the atmosphere leading to acid rains. Acid rains may cause damage to buildings. The global consumption of energy for, e.g., transportation, lighting and heating, production and delivery of goods, is expected to increase substantially not the least due to population growth and associated demands. Then to meet these demands and protect the environment as well as creating a sustainable future energy system, is a great challenge.

Fossil fuels have been formed from plants and animals that lived hundreds of millions years ago and became buried deep underneath the Earth's surface. Fossil fuels are primarily portable energy and can be stored and transported conveniently. This means that the fuel can be excavated where it is found, processed at a separate location and transported to wherever the energy is needed. Petroleum is a challenging resource as not only oil is consumed as a fuel but also is used as raw material for plastics, solvents, fertilizers, pesticides as well as other petrochemicals.

Fossil fuels exist and they provide and have provided valuable services. The dilemma of these fuels are all the side effects occurring as they are used. It is well known as fossil fuels are burned, the number one greenhouse gas contributing to global warming, CO₂, is created. It is also known that the average temperature of Earth has increased about 1 degree Fahrenheit in the 20th century. The impact of the global warming on the environment is extensive and its effect in various areas are known and often discussed publicly. Besides, there are effects on the natural ecosystems due to the collection of particularly oil and coal. For instance, oil spills have devastated ecosystems and coal mining has stripped lands of their vitality.

Nuclear energy is somewhat controversial in terms of classification. The supply of energy by nuclear technology only provides a few percent of the whole world's energy but locally the percentage might be much higher. Most likely nuclear energy will not be a major source of world energy consumption because of the public pressure and the relatively high danger associated with unleashing the power of atoms. Commonly nuclear energy is not regarded as a renewable energy source. Conventionally the nuclear energy is made by splitting up large unstable atoms of uranium. However, uranium needs to be digged out from the ground where it is available and used in nuclear fission reactors. However, some scientists hope to develop nuclear fusion reactors (making energy by joining small atoms) which will be cleaner, safer and renewable.

1.2. Renewable energy resources

Renewable energy is derived from various natural processes, such as the Sun's electromagnetic radiation, wind, tidal water, heat generation within the Earth. Solar and wind power are considered eco-friendly as they emit zero toxic gases to the environment. The main types of alternative and renewable energy sources are given below.

1. • Wind: the air motion can be harvested in wind turbin...