Hydropower

By Paul Breeze

Hydropower provides a complete discussion of the most up-to-date considerations of this method of creating renewable energy. After introducing the method’s history, the author explores various considerations for engineers, planners and managers who need to determine the best placement and size of a plant. The book then presents various types of hydropower systems, such as Run-of-River Schemes and various types of Dam and Turbines, also considering the important economic, environmental and geological impacts of each. Those involved in the planning, design and management of hydropower systems, such as engineers, researchers, managers and policymakers will find this book a very valuable and insightful resource.

• Explores different types of dams and turbines set alongside easy-to-understand diagrams, such as Embankment Dams, Concrete Arch Dams, Reaction Turbines and Francis Turbines
• Considers various economic and environmental factors significant for this type of project, such as resettlement, biodiversity and greenhouse gases
• Discusses best practices for locating a hydropower site and how to make important decisions regarding placement and method

• Language: English
• Publisher: Academic Press
• Release date: Mar 26, 2018
• ISBN: 9780128129074

Paul Breeze

Paul Breeze is a journalist and freelance science and technology writer and consultant in the United Kingdom. He has specialised in power generation technology for the past 30 years. In addition to writing Power Generation Technologies, Second Edition, he has contributed to journals and newspapers such as The Financial Times and The Economist and has written a range of technical management reports covering all the aspects of power generation, transmission and distribution.

Book preview

India

Chapter 1

An Introduction to Hydropower

Abstract

The use of water to provide mechanical power can be dated back several millennia and it was the first source of renewable electricity generation, at the end of the 19th century. It was during the 19th century that the main types of hydropower turbine in use today were developed. It remains the most important renewable source, contributing around 16% of total global electricity generation and there are several nations, such as Norway and Brazil, which rely heavily on hydropower for their electricity supply. Large hydropower schemes can be very disruptive and at the end of the 20th century hydropower development acquired a bad reputation. Since then efforts have been made to develop international standards for hydropower development. Modern hydropower plants can play an important role in helping to balance other intermittent renewable resources on the grid.

Keywords

Hydropower; water wheel; international standards; horizontal wheel; vertical wheel; gird balancing; energy storage

Hydropower was probably the first renewable energy resource in the world to be exploited and one of mankind’s first sources of mechanical power. There are indications that the use of water power may have been known in Mesopotamia as early as 4000 BC although interpretation of the evidence is difficult. Clearer evidence can be found in the first millennium BC. The earliest known literary reference is found in a Greek poem of 85 BC and there are occurrences in Roman texts too. Egyptian papyri from the second and third centuries BC also indicate the use of water wheels. Simple wheels used to drive mills and grind grain were known in China during the first century AD and by the beginning of the second millennium the technology was used widely throughout Asia and Europe. The coupling of water wheels with generators to provide electric power was initiated at the end of the 19th century in Europe and the United States.

Early mills and water wheels were relatively simple devices that used wooden paddles. Iron was introduced in the 18th century during the industrial revolution in England. This innovation led to the development during the 19th century of many of the more advanced and efficient turbines now in use in modern hydropower stations.

Hydropower capacity grew strongly during the 20th century and until late in that century it was the only significant renewable source of electrical power. According to the International Hydropower Association (IHA) the total global installed capacity of hydropower plants stood at 1246 GW at the end of 2016, including pumped storage hydropower.¹ The IHA had earlier estimated that global capacity includes at least 11,000 power stations and 27,000 generating units. Total electricity generation from hydropower was around 3983 TWh in 2014 according to the International Energy Agency. This is 16.4% of the global total electricity production in 2014 of 23,816 TWh.

Hydropower is widely distributed and only few regions are without significant hydropower potential. The countries of the developed world have exploited many of their best sites and hydropower generation forms part of the bedrock upon which developed the nations’ prosperity is based. Development elsewhere has been slower but there have been major advances in Asia, particularly in China, in recent years and many of the countries of South America rely heavily on hydropower for electricity generation. Even so, most of these regions have much remaining capacity while in Africa hydropower is significantly underdeveloped.

In spite of its potential and obvious advantages, the development of hydropower can often be difficult, particularly where large projects are concerned. Major hydropower projects are often extremely disruptive and if not developed sensitively they can lead to a range of environmental problems. Large hydro-plants, particularly those involving dams and reservoirs, will inevitably change the environment in which they are constructed leading to displacement of people and wildlife and the destruction of ecologies. With care these changes can be managed but careless and sometimes reckless development during the second half of the 20th century led to hydropower acquiring a bad reputation during the 1980s and 1990s.

Since then the industry has made an effort to reform its practices and the World Commission on Dams addressed the main problems in Dams and Development: A New Framework for Decision Making.² This report proposed a complete reassessment of the criteria and methods used to determine whether a large hydropower project should be constructed. It also laid out an approach to decision-making which took account of all the environmental and human rights issues that a project might raise, an approach that will, potentially, filter out bad projects but allow well-conceived projects to proceed.

When projects are well designed and construction is carried out carefully, large hydropower schemes have the potential to transform the lives of those who benefit from them. Many such schemes provide water for irrigation and drinking as well as power and they can allow new industries to be established too.

Economically hydropower is often considered expensive to build but when accounted for correctly it can become one of the cheapest sources of electricity available. Since 2000, the introduction of large quantities of renewable generation from wind and solar power has also led to the recognition that hydropower has an important role to play in the balancing of intermittent renewable generation on grid systems. This is leading to a further reassessment of the role of hydropower. Pumped storage hydropower plants, which are large-energy storage plants based on hydro-technology, can be used to store energy from renewable plants for use when needed. However conventional hydropower can provide significant grid support for other renewable generation too.

Large hydropower projects, above 30 MW in size, are not generally considered by regulatory authorities to be new renewable generation and in most regions do not attract support such as grants, special tariffs or tax breaks. However smaller hydropower schemes, which are generally classified as ‘small hydropower’, will often be included among the technologies that attract such support mechanisms. These smaller schemes are also less disruptive than their larger relatives and are consequently much easier to build.

The History of Hydropower

The history of water power is inextricably linked to that of the water wheel although the latter was sometimes driven by manpower or by animals and used to raise water rather than using water to provide a source of mechanical energy. However some early water wheels such as the Noria wheel did exploit the flow of water to both drive a wheel and to raise water in pots attached to its circumference. This type of water wheel is believed to have been in use in the Roman Empire from as early as 700–600