12.1 Sustainable energy supplies

Non-renewable sources of energy are the fossil fuels and nuclear fuel. These are finite so that as they are used up the supply that remains is reduced. Renewable energy can be used over and over again. It includes hydroelectric, biomass, wind, solar, geothermal, tidal and wave power. At present, non-renewable resources dominate global energy. The challenge is to transform the global energy mix to achieve a better balance between renewable and non-renewable sources of energy.

Renewable energy refers to sources of energy such as solar and wind power, which are not depleted as they are used. The energy mix is the relative contribution of different energy sources to a country’s energy production/ consumption.

Factors affecting the demand for, and supply of, energy

l Demand is primarily governed by the size of a country’s population and its level of economic development. l Growth in energy demand is particularly rapid in newly industrialised countries. l A country’s energy policy can impact significantly on demand if it focuses on efficiency and sustainability. l High levels of pollution due to energy consumption can be a strong stimulus to developing a cleaner energy policy.

Global variations in energy supply occur for a number of reasons. For example:

Physical

Deposits of fossil fuels are only found in a limited number of locations.

Economic

In poor countries foreign direct investment is often essential for the development of energy resources.

Political

International agreements such as the Kyoto Protocol can have a considerable influence on the energy decisions of individual countries.

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Trends in production and consumption

The fossil fuels dominate the global energy situation. Their relative contributions are (2008): oil – 34.8%, coal – 29.3%, natural gas – 24.1%. In contrast, hydroelectricity accounted for 6.4% and nuclear energy 5.5% of global energy. Figure 12.1 shows the regional pattern of energy consumption for 2008.

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100 % 90 80 70 60 50 40 30 20 10 0

North America

Coal South & Central America Europe &

Eurasia Middle

East Hydroelectricity Nuclear Energy Africa

Natural Gas

Asia Pacific

Oil

Figure 12.1 The regional pattern of energy consumption, 2008

l

l

l

Deindustrialisation and increasing energy efficiency in MEDCs in general has resulted in a relatively modest increase in demand compared with newly industrialised countries (NICs). In some MEDCs the demand for energy has actually fallen. It is the NICs that are increasing their energy demand by the fastest rate. China alone has accounted for one-third of the growth in global oil demand since 2000. Most LEDCs struggle to fund their energy requirements. There is a strong positive correlation between GNP per capita and energy use. Around the world 2 billion people lack access to household electricity.

Oil

From less than 60 million barrels daily in the early 1980s global demand for oil rose steeply to 84.5 million barrels a day in 2008. The largest increase has been in the Asia-Pacific region, which now accounts for 30.1% of consumption. This region now uses more oil than North America (27.4%). In contrast, Africa consumes only 3.4% of global oil. The pattern of regional production is markedly different from that of consumption. In 2008, the Middle East accounted for 31.9% of production, followed by Europe and Eurasia (21.7%). In 2008, the Middle East accounted for almost 60% % of global proved reserves. While the reserves-to-production (R/P) ratio is almost 79 years in the Middle East it is only 14.8 years in North America and 14.5 years in Asia-Pacific.

When will global peak oil production occur?

l The International Energy Agency expects peak oil production somewhere between 2013 and 2037. l The Association for the Study of Peak Oil and Gas (ASPO) predicted that the peak of global oil production would come as early as 2011.

Other sources of energy

Between 1998 and 2008 global oil production increased by 11%. Over the same period this compared with: l a rise of 35% in natural gas production. Natural gas production is dominated by the Russian Federation and the USA, accounting for 19.6% and 19.3% of the global total respectively. l a 49% increase in coal production. China alone mines 42.5% of the world total. The next largest producing country is the USA (18.0%).

Typical mistake

Students sometimes confuse areas of production and consumption. For some energy sources such as coal the figures are very similar, but for oil there is a very significant difference. The ease with which a type of energy can be transported is the major factor here.

The reserves-to-production ratio is the reserves remaining at the end of any year divided by the production in that year. The result is the length of time that those remaining reserves would last if production were to continue at that level. Peak oil production is the year in which the world or an individual oil producing country reaches its highest level of production, with production declining thereafter.

l a 13% increase in nuclear energy. With 103 operating reactors the USA leads the world in the use of nuclear electricity. This amounts to 31% of the world’s total. The next major consumers of nuclear energy after the USA are

France and Japan. l a 22% rise in hydroelectricity. The ‘big four’ HEP nations of China, Canada,

Brazil and the USA account for almost 50% of the global total.

Extending the ‘life’ of fossil fuels

There are a number of technologies that can improve the use and prolong the life of fossil fuels. These include coal gasification, clean coal technologies and the extraction of unconventional natural gas. Such techniques may be very important in buying time for more renewable energy to come on-line.

Renewable energy

Hydroelectricity dominates renewable energy production. The newer sources of renewable energy that make the largest contribution to global energy supply are wind power and biofuels.

Hydroelectric power

Most of the best HEP locations are already in use so the scope for more largescale development is limited. However, in many countries there is scope for small-scale HEP plants to supply local communities.

Although HEP is generally seen as a clean form of energy it is not without its problems: l Large dams and power plants can have a huge negative visual impact on the environment. l The obstruction of the river affects aquatic life. l Deterioration in water quality is common. l Large areas of land may need to be flooded to form the reservoir behind the dam. l Submerging large forests without prior clearance can release significant quantities of methane – a greenhouse gas.

Wind power

The worldwide capacity of wind energy is approaching 100,000MW. Global wind energy is dominated by a relatively small number of countries. Germany, the USA and Spain together account for almost 58% of the world total. Wind energy has reached the ‘take-off’ stage, both as a source of energy and a manufacturing industry.

MW 100 000 80 000

60 000

40 000

20 000

0

1996 1998 2000 2002 2004 2006

Figure 12.2 Wind energy – global cumulative installed capacity, 1996–2007

Apart from establishing new wind energy sites, repowering is also beginning to play an important role. This means replacing first-generation wind turbines with modern multi-megawatt turbines, which give a much better performance.

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As wind turbines have been erected in more areas of more countries, the opposition to this form of renewable energy has increased: l People are concerned that huge turbines located nearby could blight their homes and have a significant impact on property values. l There are concerns about the hum of turbines disturbing both people and wildlife. l Skylines in scenically beautiful areas might be spoiled forever. l Turbines can kill birds. Migratory flocks tend to follow strong winds but wind companies argue that they steer clear of migratory routes.

Biofuels

Biofuels are fossil fuel substitutes that can be made from a range of agri-crop materials including oilseeds, wheat and sugar. They can be blended with petrol and diesel. Increasing amounts of cropland have been used to produce biofuels. Initially, environmental groups such as Friends of the Earth and Greenpeace were very much in favour of biofuels, but as damaging environmental consequences became clear such groups were the first to demand a rethink of this energy strategy.

Geothermal electricity

Geothermal energy is the natural heat found in the Earth’s crust in the form of steam, hot water and hot rock. Rainwater can percolate several kilometres in permeable rocks where it is heated due to the Earth’s geothermal gradient. This source of energy can be used to produce electricity or the hot water can be used directly for industry, agriculture, bathing and cleansing. For example in Iceland, hot springs supply water at 86°C to 95% of the buildings in and around Reykjavik.

Steam control valves in geothermal plants Natural fissure: steam from the heated groundwater rises up

Permeable rock containing hot water or steam under pressure

Surface water runs down fissure into hot permeable rock Impermeable rock Heat from volcanic activity and other processes

Source: IGCSE Geography by P. Guinness & G. Nagle (Hodder Education, 2009), p.144

Figure 12.3 Geothermal power

The USA is the world leader in geothermal electricity. However, total production accounts for just 0.37% of the electricity used in the USA. Other leading geothermal electricity-using countries are the Philippines, Italy, Mexico, Indonesia, Japan, New Zealand and Iceland.

Solar power

From a relatively small base the installed capacity of solar electricity is growing rapidly. Experts say that solar power has huge potential for technological improvement, which could make it a major source of global electricity in years to come. Spain, Germany, Japan and the USA currently lead the global market for solar power.

Solar power is currently produced in two ways: l Photovoltaic systems – these are solar panels that convert sunlight directly into electricity. l Concentrating solar power (CSP) systems use mirrors or lenses and tracking systems to focus a large area of sunlight into a small beam. This concentrated light is then used as a heat source for a conventional thermal power plant.

Expert tip

Solar power is generally taken to mean the production of solar electricity, as distinct from solar hot water systems, which are commonplace in many countries with a large number of days with sunshine each year.

Tidal power

Although tidal power is currently in its infancy, a study by the Electric Power Research Institute estimated that as much as 10% of US electricity could eventually be supplied by tidal energy. This potential could be equalled in the UK and surpassed in Canada. The 240MW Rance facility in northwest France is the only utility-scale tidal power system in the world. The greatest potential for tidal power is in Canada’s Bay of Fundy in Nova Scotia.

Fuelwood in developing countries

In developing countries about 2.5 billion people rely on fuelwood (including charcoal) and animal dung for cooking. Fuelwood accounts for just over half of global wood production. It provides much of the energy needs for Sub-Saharan Africa and is also the most important use of wood in Asia. In developing countries the concept of the ‘energy ladder’ is important. Here, a transition from fuelwood and animal dung to ‘higher-level’ sources of energy occurs as part of the process of economic development.

The environmental impact of energy

The environmental impact of fossil fuels has been the subject of much debate over a long period of time, as have the significant concerns over nuclear energy. Even in the renewable sector the impact of large hydroelectric schemes has drawn considerable criticism along with increasing concerns over large wind farms. No energy project of a significant scale is without its disadvantages.

The Niger Delta

No energy production location has suffered more environmental damage than the Niger Delta, which contains over 75% of Africa’s remaining mangrove. A 2006 report estimated that up to 1.5 million tonnes of oil have been spilt in the delta over the past 50 years. The report compiled by WWF says that the Delta is one of the five most polluted spots on Earth. Pollution is destroying the livelihoods of many of the 20 million people who live in the area. The pollution damages crops and fishing grounds and is a major contributor to the upsurge in violence in the region. People in the Delta are dissatisfied with bearing the considerable costs of the oil industry but seeing very little in terms of the benefits. The flaring (burning) of unwanted natural gas found with the oil is a major regional and global environmental problem. The gas found here is not useful because there is no gas pipeline infrastructure to take it to consumer markets. Gas flaring in the Niger Delta is the world’s single largest source of greenhouse gas emissions. The federal environmental protection agency has only existed since 1988 and environmental impact assessments were not compulsory until 1992.

Oil sands in Canada and Venezuela

Huge oil sand (tar sand) deposits in Alberta, Canada and Venezuela could be critical over the next 50 years as the world’s production of conventional oil falls. However, there are serious environmental concerns about the development of tar sands: l It takes two tonnes of mined sand to produce one barrel of synthetic crude, leaving lots of waste sand. l It takes about three times as much energy to produce a barrel of Alberta oil-sands crude as it does a conventional barrel of oil. Thus, oil sands are large sources of greenhouse gas emissions.

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An environmental impact assessment is a document required by law detailing all the impacts on the environment of a project above a certain size. Oil sands, also known as tar sands or extra heavy oil, are naturally occurring mixtures of sand or clay, water and an extremely dense and viscous form of petroleum called bitumen.