2010 Diary week 49
Climate Change: A Strategy for Action
Book Review
Below you will find Part 4 of the review of Chapter 11 of Global Warming: The Complete Briefing by John Houghton with the title ‘Energy and Transport for the Future’. These are some snippets: “In 1990 the world consumption of energy was about 8,730 million tonnes of oil equivalent (toe). This can be converted into physical energy units to give an average of energy use of about 12 million million watts (or 12 Terawatts). Great disparities exist in the amount of energy used per person in various parts of the world. In 1990 each person in the world used on average 1.65 toe, an average consumption of energy of about 2.2 kilowatts (kW). The highest rates of energy consumption are in North America where the average citizen in 1990 used nearly 8 toe, equivalent to an average rate of consumption of about 11 kW. By contrast the average Indian used only 1/20th of that amount or about 0.4 toe, equivalent to an average rate of consumption of 0.5 kW, mainly in the form of traditional fuels.” “Taking the world average, about 20% of primary energy is used in transportation, about 45% by industry and the remaining 35% in commercial activity and in homes. About 1/3rd of primary energy goes to make electricity at an average efficiency of conversion of about 1/3rd. Of this electrical power about half, on average, is utilized by industry and the other half in commercial activities and in homes.” “Up to the year 2020 the energy demand and the carbon dioxide emissions for the IPCC business-as-usual scenario IS 92a and the future projections generated by the World Energy Council (WEC) reference scenario B1 are similar.” “To provide 1 unit of electrical energy power at the point of use typically requires about 3 units of primary energy. An incandescent light bulb is about 3% efficient in converting primary energy into light energy; unnecessary use of lighting reduces the overall efficiency to about 1%.” “The results of a study in the United States have identified some of the large savings which could be made in the electricity used in buildings. The cost of such action would be less than the cost of the energy savings; overall therefore there would be a substantial net saving. The four options which provide the largest savings (together adding up to 60% of the savings) are in the areas of commercial lighting, commercial air conditioning, residential appliances, and residential space heating.”
GLOBAL WARMING
THE COMPLETE BRIEFING
JOHN HOUGHTON
Co-Chairman of the Scientific Assessment Working Group of the Intergovernmental Panel on Climate Change
CAMBRIDGE UNIVERSITY PRESS REPRINTED 1999
PART IV
Chapter 11: Energy and Transport for the Future
We flick a switch and energy flows. Energy is provided so easily for the developed world that thought is rarely given to where it comes from, whether it will ever run out or whether it is harming the environment. Energy is also cheap enough that little serious attention is given to conserving it. However, most of the world’s energy comes from the burning of fossil fuels which generates a large proportion of the greenhouse gas emissions into the atmosphere. If these emissions are to be reduced, a large proportion of the reduction will have to occur in the energy sector. There is need, therefore, to concentrate the minds of policymakers and indeed of everyone on our energy requirements and usage. This chapter looks at how future energy might be provided in a sustainable manner.
World energy demand and supply
• Most of the energy we use can be traced back to the sun. In the case of fossil fuels it has been stored away over millions of years in the past.
• If wood (or other biomass including animal and vegetable oils), hydro-power, wind or solar energy itself is used, the energy has either been converted from sunlight almost immediately or has been stored for at most a few years.
• These latter sources of energy are renewable; they will be considered in more detail in the chapter.
• The only form of energy that does not originate with the sun is nuclear; this comes from radioactive elements which were present in the Earth when it was formed.
• Until the Industrial Revolution, energy for human society was provided from ‘traditional’ sources – wood and other biomass and animal power. Since 1860, as industry has developed, the rate of energy use has multiplied by a factor of 30, at first mostly through the use of coal followed, since about 1950, by rapidly increasing use of oil.
• In 1990 the world consumption of energy was about 8,730 million tones of oil equivalent (toe). This can be converted into physical energy units to give an average of energy use of about 12 million million watts (or 12 Terawatts).
• Great disparities exist in the amount of energy used per person in various parts of the world. In 1990 each person in the world used on average 1.65 toe, an average consumption of energy of about 2.2 kilowatts (kW).
• The highest rates of energy consumption are in North America where the average citizen in 1990 used nearly 8 toe, equivalent to an average rate of consumption of about 11 kW.
• By contrast the average Indian used only 1/20th of that amount or about 0.4 toe, equivalent to an average rate of consumption of 0.5 kW, mainly in the form of traditional fuels.
• About half the world’s population rely wholly on traditional fuels and do not currently have access to commercial energy in any of its forms.
• Taking the world average, about 20% or primary energy is used in transportation, about 45% by industry and the remaining 35% in commercial activity and in homes.
• About 1/3rd of primary energy goes to make electricity at an average efficiency of conversion of about 1/3rd. Of this electrical power about half, on average, is utilized by industry and the other half in commercial activities and in homes.
• Taking the world as a whole, the amount spent per year by the average person for the 1.65 toe of energy used, is about 5% of annual income. Despite the very large disparity in incomes, the proportion spent on primary energy is much the same in developed countries and developing ones.
• If we continue to generate most of our energy from coal, oil and gas, do we have enough to keep us going? Current knowledge of proven recoverable reserves indicates that known reserves of fossil fuel will meet demand for the period up to 2020 and substantially beyond.
• Around mid-century (2050), if demand continues to expand, oil and gas production will come under increasing pressure. Increased difficulty of extraction can be expected to lead to a rise in price.
• So far as coal is concerned, there are operating mines with resources for production for well over 100 years.
• At current rates of use, reserves of oil and gas are likely to be available for 100 years and of coal for more than 1,000 years. There are also additional reserves such as the methane hydrates, which are very large in quantity but from which extraction would be much more difficult.
• Reserves of uranium for use in ‘fast’ nuclear reactor power stations are believed to be at least 3,000 Gtoe and possibly as high as 9,000 Gtoe, substantially greater than likely fossil fuel reserves.
• For at least the next century, sufficient fossil fuels in total are available to meet likely energy demand. It is considerations other than availability, in particular environmental considerations, which will tend to limit fossil fuel use.
Future energy projections
• No one knows how human beings will behave or what political, institutional or technical changes may occur. Nevertheless a range of possibilities must be considered in order to predict what climate change might occur.
• The predictions of climate change drawn up in Chapter 6 based on a business-as-usual scenario prepared under the auspices of the IPCC (scenario IS 92a) estimated future energy demand on the assumption that no controls or constraints for environmental reasons were applied.
• Four energy scenarios constructed by the World Energy Council (WEC) take into account likely population growth and energy sources and a realistic view of the rate of technical change.
• One of the scenarios, the ‘high growth’ case (A), assumes a higher rate of economic growth in developing countries. An ‘ecologically driven’ case (C) assumes that environmental pressures have a large influence on energy demand and growth. The other scenarios (B and B1), are based on moderate assumptions about economic growth.
• It is only in the developed world that there is potential for containing future energy demand. Population growth and the need for economic development in developing countries make it inevitable that they will, for many decades, consume increased amounts of energy.
• For all the scenarios to 2020, fossil fuels continue to dominate the energy mix. The contribution from nuclear power is assumed to grow in all the cases. New renewable energy sources play an increasing role, although apart from case C their contribution is modest.
• For the ‘ecologically driven’ WEC scenario C the energy demand in 2020 is about 30% more than in 1990 and 30% less than that for scenario A.
• Scenario C assumes both that there will be large increases in efficiency leading to a reduced energy demand and also, following the results of a WEC study on renewable energy, a substantial growth in the share of primary energy supply coming from new renewable sources (‘modern’ biomass, solar, wind and so on).
• A growth in energy supply from these new renewable sources from 2% in 1990 to 12% in 2020 (by when 1.4 Gtoe per year would be coming from these sources) is considered feasible if their development is given sufficient support.
• By the year 2100 under scenario C, 50% of energy supply is assumed to come from these sources.
• The WEC report points out that ‘cost effective research, development and installation involving financing which only governments can supply will be needed if these sources of energy are to be implemented on the large scale shown in the Ecologically Driven Case C’.
• Up to the year 2020 the energy demand and the carbon dioxide emissions for the IPCC business-as-usual scenario IS 92a and the future projections generated by the WEC reference scenario B1 are similar.
• After about the middle of the century, the WEC scenarios assume more strongly than the IPCC ones that growth in energy demand and also in carbon dioxide emissions will begin to be limited by the increasing scarcity and price of oil and gas.
• For all these scenarios, except WEC scenario C, atmospheric concentrations of carbon dioxide continue to rise throughout next century. The WEC scenario C comes near to stabilizing emissions over the period to 2020 and to stabilizing atmospheric concentrations by 2100.
• In its 1995 Report, the IPCC has developed a number of projections (the Low-Emissions Supply Systems or LESS constructions) showing how the necessary energy supply next century could be provided with different options of energy supply especially with respect to renewable energies.
Energy conservation and efficiency
• The energy available in the coal, oil, gas, uranium, hydraulic or wind power is primary energy. The process of energy conversion, transmission and transformation into its final useful form involves a proportion of the primary energy being wasted.
• To provide 1 unit of electrical energy power at the point of use typically requires about 3 units of primary energy.
• An incandescent light bulb is about 3% efficient in converting primary energy into light energy; unnecessary use of lighting reduces the overall efficiency to about 1%.
• Although there is some difficulty in defining precisely the performance of ‘ideal’ devices, assessments come up with world average end-use energy efficiencies of the order of 3%, suggesting that there is a large amount of room for improvement in energy efficiency, perhaps by at least threefold.
• The following paragraphs consider three areas where there are real possibilities of savings: in buildings, in industry and in transport.
Energy use in buildings
• In the United States about 36% of the total use of energy is in buildings (about ⅔ of this is in electricity), including about 20% for their heating (including water heating) and about 3% for cooling them.
• Two ways in which really substantial energy savings can be made in buildings are by improving their insulation and by improving the efficiency of appliances.
• Many countries, including the UK and the USA still have relatively poor standards of building insulation compared with Scandinavian countries. Improvements in building design to make better use of energy from sunlight can help. There are large possibilities for the improvement of the efficiency of appliances at relatively small cost.
• The results of a study in the United States have identified some of the large savings which could be made in the electricity used in buildings. The cost of such action would be less than the cost of the energy savings; overall therefore there would be a substantial net saving.
• The four options which provide the largest savings (together adding up to 60% of the savings) are in the areas of commercial lighting, commercial air conditioning, residential appliances, and residential space heating.
• Energy companies in some parts of the United States are contracting to implement some of these energy saving measures as an alternative to the installation of new capacity – at significant profit both to the companies and its customers.
• Similar savings would be possible in other developed countries, countries with economies in transition and in developing countries if existing plant and equipment were used more efficiently.
• Similar room for efficiency savings exist in industry. The cogeneration of heat and power, which already enables electricity generators to make better use of heat which would otherwise be wasted, is particularly applicable to some industrial plants where large amounts of both heat and power can be required.
Energy used for transport
• In the developed world between one fifth and one quarter of energy use is for transport, and it is a rapidly growing proportion. Road transport accounts for the largest proportion of this, over 80% in industrialized countries. Air transport is next at 13%.
• In the United Kingdom, if the present trend in motor-car use continues, in about 30 years time (in the year 2025) there will be twice as many cars doing twice as many miles – and the situation is very similar elsewhere.
• The proportional growth in developing countries could be even more rapid. Increased prosperity also brings with it increased movement of freight.
• There are two types of action which can be taken to curb the energy use of transport. The first is to increase the efficiency of fuel use. It is estimated that the average fuel consumption of the current fleet of motor cars could be halved through the use of existing technology – more efficient engines, light-weight construction and low-air-resistance design – while maintaining an adequate performance.
• The second action is to plan cities and other developments so as to lessen the need for transport and to make personalized transport less necessary – work, leisure and shopping should all be easily accessible by public transport, or by walking or cycling. Public transport should be reliable, convenient, affordable and safe.
Coal-fired power stations
• The efficiency of coal-fired power stations has improved from about 32%, a typical value of 20 years ago, to about 42% for a pressurized fluidized bed combustion plant of today.
• Gas turbine technology has also improved providing efficiency improvements from about 36% for an average plant to 45% for the best modern plant.
• Substantial further gains in overall efficiency can be realized by making sure that the large quantities of low-grade heat generated by power stations is not wasted but utilized.
• To prevent carbon dioxide entering the atmosphere, it can either be removed from the flue gases or the fossil fuel feedstock could, in a gasification plant, be converted through the use of steam, to carbon dioxide and hydrogen. The carbon dioxide is then relatively easy to remove and the hydrogen can be used as a versatile fuel.
• Carbon dioxide can be dumped into spent oil or gas wells or into the deep ocean. In Norway, where there is a carbon tax of 15$US per tonne of carbon, a company is finding it economic to pump over one million tonnes per year of carbon dioxide removed from a natural gas stream into storage under the North Sea.
Wood and other biomass
• The main source of energy for half the world’s population is largely from wood or other biomass. Although these sources are renewable, it is important that they are employed efficiently, and a great deal of room for increased efficiency exists.
• Much cooking is carried out on open fires where only about 5% of the heat reaches the inside of the cooking pot.
Energy is cheap
• Basic energy is so cheap that without both encouragement and incentives, progress with the implementation of many of the proposals will be limited. Some of the policy instruments mentioned later could address this issue.