Fusion Technology 1996 (eBook)

F. Serra, C. Varandas (Herausgeber)

eBook Download: PDF | EPUB

2012 | 1. Auflage
650 Seiten
Elsevier Science (Verlag)
978-0-444-59975-9 (ISBN)

Infos

The objective of these proceedings was to provide a platform for the exchange of information on the design, construction and operation of fusion experiments. The technology which is being developed for the next step devices and fusion reactors was also covered.

Textauszug

Nuclear fusion, an energy source

R. Toschi,     The NET Team, Boltzmannstr. 2, D-85 748 Garching, Germany

Abstract

The final phase of the feasibility demonstration of fusion, namely the construction and operation of ITER, will require a large and prolonged effort and strong determination by all parties involved. The time is therefore appropriate to revisit the motivations in support of fusion development. The supply of energy would become an issue today if due consideration were given not only to the limits ‘internal’ to the energy systems but also to those ‘external’, to it. The first ones are not so stringent because reserves in particular of fossil fuels are ample, but the second ones are very stringent because of the limited capability of self-regeneration of the environment. Energy consumption is anticipated to triple in the next 50 years and if the share among the sources remains as of now the risk of a major climate change due to the release of CO2 from burning of fossil fuels, with catastrophic consequences on the environment, is high. The development of sources with better compatibility with the environment and acceptable to society, such as fusion, as well as of more efficient energy technologies, should be pursued with a great determination. The potential of fusion as an energy source could be demonstrated in all of its main aspects by carrying out the ITER programme.

1 Introduction

The development of thermonuclear fusion as an energy source has now reached the crucial stage of launching the full feasibility demonstration phase with the construction and operation of an experimental reactor, called ITER (International Thermonuclear Experimental Reactor) [1]. ITER will have the size, the power and most of the technologies of a reactor and it will require a large, prolonged and coordinated effort from the partners involved.

To be successful, such an enterprise, which has no precedent in the history of science, requires on the part of the partners strong determination, which can only stem from the conviction that fusion is an energy source with such a potential of social acceptability that it must be made available to mankind. In the following we shall discuss reasons in support to this conviction, addressing the following questions:

• Is energy an issue today?

• How can future energy demand be met?

• How can fusion contribute to future energy supply?

• How and when is fusion going to demonstrate its potential as an energy source?

2 Is energy an issue today?

2.1 Energy and environment

At this time when the supply of fossil fuel is plentiful, cheap and apparently secure many believe that there is no ‘energy issue’. In fact, energy becomes an issue only in conjunction with political instabilities in the oil producing countries. Even a slight turbulence like the one in early September ‘96 in the Middle East has prompted a few editorials in newspapers reminding us that energy supply should receive more attention and, this time, with some emphasis on environmental compatibility. Once these political and regional instabilities are suppressed then the ‘energy issue’ rapidly disappears. Only the 1973 energy crisis had somewhat longer lasting effects on the energy supply structure in some countries in favour of nuclear fission and on new energy sources development. In spite of several initiatives, such as the Earth Summit in Rio de Janeiro in 1992, public opinion seems insufficiently aware of other ‘instabilities’, related to the energy ‘quality’ rather then ‘quantity’, which may have far more dramatic consequences and not only on a regional scale but on a planetary scale.

Some energy related issues on a planetary scale were addressed in the early seventies in the MIT study ‘The Limits to Growth’ [2] where it was argued that due to the depletion of non-renewable resources, population growth and pollution, a material limit to growth would be reached leading to a sudden and uncontrollable economic decline of society. Even this alarm did not last very long because, under the pressure of the 1973 energy crisis, new oil/gas resources were found, nuclear energy was allowed to expand and technical innovations were believed to reduce substantially the ‘energy intensity’ (i.e. energy required to produce a unit of gross national product). In the seventies the concern was mainly on possible limits ‘internal’ to the energy system rather than on limits ‘external’ to it such as the finite absorptive capacity of the environment as a whole. We should instead be aware that the environment simply cannot absorb for much longer at the present rate the ‘waste’ of human activities in general and of energy production in particular. Since the selection of primary energy sources for electricity production is driven by economic considerations it is now time that energy sources be judged and ranked for the best combination of ‘all’ costs including the so called ‘externalities’ [3], namely the costs to the environment and to human health associated with the use of each energy source, costs which are now, in general, passed over to society and to future generations.

2.2 Present energy consumption and sources of energy [4]

The total energy consumption in the world amounts to about 13 TWY1. The average consumption pro capita is about 2.2 kWY but vast disparities among different countries exist, e.g. US, 11 kWY; EU 5, kWY; China, 0.8 kWY and India, 03 kWY. The richest 20% of the world population use 55% of the primary energy and their pro capita consumption is almost five times as much as for the rest of the world population.

The global consumption of 13 TWY is shared among different sources as follows: nuclear (6%), hydro (7%), biomass (10%), fossil (77% of which 45% from oil, 30% from coal, 25% from natural gas).

Electricity production is responsible for about 30% (3.7 TWY) of the total energy consumption and the primary sources for it are: fossil (60%), nuclear (20%) and hydro (20%).

These data confirm the dominant role of fossil sources in the supply of energy both globally and for electricity. The role of fossil fuels is justified by the oil price (at a constant dollar today’s price is only twice as much as it was before 1973 crisis), by the prospects of abundant reserves which, in spite of increased consumption are today estimated to last longer then 25 years ago (50 vs. 25 years) and, finally by the dramatic increase in the natural gas reserves estimated to be at least as large as the oil reserves. Furthermore, the present trend is to increase further the role of fossil fuels in electricity generation using natural gas because of its more favourable economic prospects than other sources (e.g. smaller size, shorter construction time, higher efficiency).

2.3 How the energy demand may evolve till mid next century

The world population, according to most studies [4], will increase from the present 5.3 billion to about 10–11 billion in the middle of next century and possibly stabilise thereafter. This increase is expected to occur mostly in the developing countries and to be accompanied by a large concentration in urban areas (from present 50 up to 75%). In the period 1970–1990 the pro capita total energy consumption has increased by 1% per year and electricity consumption by 3% per year. For the future a most prudent scenario assumes a significant decrease of energy intensity (0.5%/year) allowing pro capita primary energy consumption to increase at a lower rate than in the past (0.5%/ year). This assumption implies a development of energy efficient technologies which would require important resources not necessarily available at times of abundant fossil fuel supply. According to this scenario by the year 2050, the pro capita primary energy consumption would increase by about 30%. This means that, even if such an increase is concentrated only on developing countries, they would reach in 2050 a pro capita energy consumption still less than half of the one in the EU today.

Under these prudent extrapolations the total energy demand in 2050 would more than double, approaching 30 TWY.

Over a third of the total energy would be used to produce electricity having taken into due account both the likely faster increase rate in the demand and the improvement in the conversion efficiency. Actually, in the last 5 years in the richest 20% of the world population, primary energy demand grew at the same rate as the economy, i.e. energy intensity did not improve. This extrapolation is also prudent considering that today the richest 20% of the population use 75% of all electricity. This share of electricity is very close to the share of the world Gross Domestic Product.

2.4 Can the present energy sources meet the future energy demand?

2.4.1 Energy reserves

The proven recoverable reserves of energy can be summarised as follows (measured in TWY and in years of duration at...

Produkt-Details

• Erscheint lt. Verlag: 2.12.2012
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Atom- / Kern- / Molekularphysik
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Optik
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Plasmaphysik
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Quantenphysik
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Wirtschaft
• ISBN-10: 0-444-59975-4 / 0444599754
• ISBN-13: 978-0-444-59975-9 / 9780444599759