It is a great pleasure, and an honour, to be given the opportunity to open this Symposium. That the subject is of major and widespread interest can be shown by the impressive list of speakers who have agreed to address us in the next two days and also by the encouraging response we have had from those wishing to attend. There can, indeed, be few subjects of greater importance to our future prosperity than energy supplies. After the upheavals of the last thirteen years, in which the international oil price rose so dramatically in two major surges from 3 dollars a barrel in 1973 to a peak of over 40 dollars in 1980 and has now, since last November, fallen from 30 to 15 dollars, this point needs little emphasis. The intolerably high levels of unemployment which still plague the industrial world are at least in part a consequence of the economic dislocation which these price changes brought about; so too is the problem of excessive debt in many of the less developed countries with its serious threat to the world financial system.

The main features of energy demand in Scotland are described and compared, in respect of total energy use and the shares supplied by the different fuels, with the figures for the United Kingdom and other countries. Recent trends in demand are examined to illustrate how the present position has been reached and factors likely to influence each fuel's share in the future are outlined. The role of the energy industries themselves is discussed and the scope for new initiatives by these industries indicated.

Since the assessment of coal reserves for the Royal Commission on the coal industry of Great Britain made nearly a century ago, up to assessments made by geologists of the National Coal Board, it has been evident that the coalfields of Scotland contain considerable quantities of coal. Throughout the past two decades the presence of hydrocarbons in the rocks beneath the North Sea, the general abundance of oil in various parts of the world, and the development of nuclear power, has meant that coal is only one of several sources of energy readily available to us. The coalfields of Scotland contain seams of varying quality and energy content and so can be compared with other fuels. Consequently it is the cost of the energy to the consumer that is often the controlling factor in the choice of which fuel to use. The very nature of coal as a bulky and not-too-easily-handled fuel has meant that only the generation of electricity offers the scope for substantial consumption of coal.

The paper examines these factors and also the location of the coal reserves in Scotland, particularly in the light of the geological factors that affect the cost of the energy. The National Coal Board's deep mining exploration programme in Great Britain has sought opportunities for new ventures and developments, some of which have been in Scotland. The market for the coal and the competition for that market clearly indicates that the productivity of coal mining operations is paramount in determining the future size of the coal industry in Scotland. About half of the coal can be provided from low-cost opencast operations, with the other half obtained from the mines with the highest productivities—productivities that result in energy costs similar to those obtained from oil and nuclear power.

Some 6 billion of the 14 billion barrels of proven reserves on the United Kingdom Continental Shelf have already been produced. The remaining 8 billion barrels are reasonably insensitive to oil prices even as low as $10 per barrel, as the operating costs of most existing fields are below $7 per barrel. Production from these proven reserves is already dropping from a peak of just under 3 million barrels per day towards 0·3 million barrels per day in the year 2000.

A description of the buried sequence in the northern North Sea and the frontier area towards Rockall and Faeroe leads to an assessment of probable oil reserves somewhat more conservative than the Department of Energy best guess of 44 billion barrels. Further developments will be sensitive to the course of oil prices, but at least another 8 billion barrels could be added to the proven reserves.

The world is consuming oil far faster than it is finding it, and the supply must be dominated again by the Middle East producers as production declines.

This paper considers market fundamentals rather than privatisation, which is largely about organisation. During the last ten years there has been significant growth in the size of the world's remaining proven gas reserves. The proven reserve production ratio has been growing and is now sixty years. Beyond proven reserves there are reserves in the “probable” and “possible” categories. Within Western Europe, gas reserves are principally located in Norway, the Netherlands and the United Kingdom. Additional reserves are accessible to Western Europe. For the United Kingdom, gas supplies are probably ample in the short to medium term. In the longer term there is likely to be a need for imports but there are various potential suppliers. At the Church House debate in 1976 many were obsessed with “energy gaps”; today's conventional wisdom is “market forces”. Energy forecasts have proved inaccurate, but gas demand has been fairly close to projections. Over the last ten years the role of gas in energy markets has been growing, such that gas is now the major fuel in non-transport energy demand. Gas now dominates the domestic market for energy in Britain. Growth in customers continues in Scotland and the rest of Britain. Nevertheless, there is fierce competition in the domestic market with millions of decisions taken on acquiring and replacing appliances each year. The growing role of gas in Scottish and British industrial and commercial markets is discussed, with faster growth overall in demand in Scotland than Britain as a whole. The recession has had its effect but gas suffered less than some other fuels. Growth in gas demand from industry has resumed. Great emphasis is placed upon improving the efficiency of gas use. Used wisely, an availability of gas is foreseen on a long term basis.

The present buyer's market in energy is likely to continue for several years, but in the longer run the disparity in resources and consumption rates among the principal fuels will result in renewed shortage and price rises for oil and natural gas. In the longer term the major energy importers must rely on the broad international market in coal and uranium. A useful insurance for power producers will be to invest overseas in the production of their fuels.

The background to recent major advances in the construction and operation of fast reactors is outlined with particular reference to the Dounreay Prototype Fast Reactor. The advantages and disadvantages of sodium as a coolant of the high energy density assembly are discussed and an account given of the consequences of a leak and the precautions taken against this eventuality. Attention is drawn to the safety aspects of the system. The economics of the plans for fuel reprocessing are explained and an account given of the progress in the fabrication of fast reactor fuel pins. Finally the environmental impact of present and planned activities on the Dounreay site is presented in the context of participation in the European Collaboration on Fast Reactor Technology and attention drawn to the importance of the planning inquiry in progress at Dounreay.

Renewable energy sources are assessed on the basis of the practically available size of the reserve and the economic competitiveness of its development. Solar water heating panels are expensive, but attention to passive solar heating and heat retention in house design is inexpensive and rewarding. Photovoltaic cells remain expensive for United Kingdom use but are likely to be useful in small specialised applications. Offshore wave power needs bulky and expensive structures, though economic generation may be possible at favoured points on rocky shores. Wind power is nearly competitive with conventional electricity generation and offers an attractive export market even with a small United Kingdom base. Total power promises to be economic but it involves very large installations where the obstacle is the huge initial investment. Geothermal energy from hot, dry rocks has yet to show acceptable heat generation rates. The most promising renewable energy source at present is man-made; domestic, industrial and agriculture waste used as fuel.

The organisation of the generation and supply of electricity in Scotland by the South of Scotland Electricity Board and the North of Scotland Hydro Electric Board is detailed and differences from the other nationalised energy industries in Scotland and from the arrangements for the supply of electricity in England and Wales noted. The present plant position is described and the flexibility in the fuels used underlined. The experiences of the last thirty years are analysed and an account given of the response of the Boards to the crises of dramatic oil price increases and the 1984/85 dispute in the coal industry. Attention is given to the forward planning problems arising from the long construction time of a new station and the delays that may be involved with public inquiries. The opportunities for exporting power to England after the modest anticipated rises in Scottish demands are met are cited as a factor in the budgetting. The difficulties the Combined Heat and Power projects, being studied for a number of major cities including Edinburgh, present to the Boards are listed. Finally the implications for suppliers and contractors of the necessary replacement before the end of the century of equipment associated with the distribution system are noted.

The large hydro-electric schemes developed by the early 1960s now (1984/85) supply 12% of Scottish electricity demand. The pumped storage schemes contribute to the balance of production and demand but are not nett producers of electric power. Schemes remaining for development are numerous but small, in the range below 10 MW. Private development for local use is the best economic prospect for schemes below 500 kW. A rolling five-year programme of 10–15 MW per annum is suggested for the development of remaining resources. In Scottish conditions, peat does not appear to be a viable alternative to diesel power. Wave power is practicable, but probable costs are too high to justify investment at present. Wind power is promising, especially for island sites, but not as a complete replacement for diesel. Developments since 1980 include a successful small machine on Fair Isle and machines at 250 and 300 kW on Orkney where a 3 MW generator is being erected. A 750 kW machine has been ordered for Shetland.

The meaning to be assigned to “pollution” is discussed and an account given of the “natural” sources of radiation. The effects of radiation on human populations are described. The artificial sources of radiation in the environment associated with energy productions are reviewed. Particular attention is given to the effects of the discharge of radioactive waste on radiation exposures in the neighbourhood of nuclear establishments. This is followed by a consideration of nuclear accidents and the public reaction to them. Radioactive pollution and the necessary organisation for its control are discussed with particular attention being paid to the present position in the United Kingdom.

This paper discusses the four main invisible products of fossil fuel combustion: carbon dioxide, sulphur dioxide, nitric oxide and unburned hydrocarbons. If carbon exchanges between atmosphere, ocean and biosphere remain at their recent levels, the CO2 concentration in the atmosphere is likely to double later next century, with a possible rise in global mean temperatures of around 2°C resulting in significant changes in regional climates. The consequences are uncertain, but with adequate research, there should be time to develop the understanding necessary to guide future policies. Sulphur dioxide, acid rain and photochemical oxidants are a more pressing problem. Knowledge here is more complete, but still subject to considerable uncertainties that have an important bearing on the extent and rate of response of affected areas to reduction in acid deposition. However, from the year 2000 onwards, with the replacement of existing plant with nuclear power or new sulphur-free coal-burning technology, United Kingdom sulphur emissions will continue to decline at about twice the pace of their previous rise. Nitrogen oxides contribute to rain acidity, may have direct toxic effects on plants and, when accompanied by hydrocarbons, can generate ozone, itself a damaging pollutant. The chemistry of ozone production is, however, complex, such that intuitive control policies could be counter-productive.

Risk involves consideration both of the consequences of accidents and the frequency with which the accidents occur. Indeed formally risk is equal to the product of frequency and consequences. The important question of the perception of risk by the public and by the professional is first addressed. Two tenets are proposed as being a suitable summary of the public requirement:

1. If it can happen, then it must not matter.

2. If it matters, then it must not happen.

A mathematical interpretation is placed upon these tenets and is shown to be consistent with various professional safety targets. The tenets do not indicate what numerical values for risk would be acceptable to the public but they do show how the consequences of accidents should diminish as the frequency or likelihood of a particular accident increases. It is argued that the best way of determining what level of risk the public accepts is to be guided by statistics for man-caused accidents. These, it transpires, pose risks which are considerably greater than those implied, for example, by the professional targets for nuclear reactors. The risk posed to the public by two energy installations is summarised. The one installation, situated on Canvey Island, exports energy in the form of gas, some of which (methane) is pumped into a national gas grid. The other installation, the Sizewell “B” Pressurised Water Reactor nuclear power station has not yet been constructed, but a comprehensive risk assessment has been undertaken, the results of which are summarised. The two installations are comparable in the sense that each exports a power of the order of a million kilowatts (in the form of gas in the one case and electricity in the other). Both have been the subject of Public Inquiries. The risks posed by the Canvey installations are accepted, since they only constitute a small fraction of the risks which the public run in any case during the course of their everyday lives. The predicted risks for the PWR are smaller still. The form taken by the risks posed by both installations corresponds broadly with the two tenets. That is to say the greater the consequences the lower should be the frequency of a particular accident.

If technology aims to direct natural forces for the use and convenience of man, the inconvenience or worse arising from the concomitant hazards requires attention. The quantitative assessment of risk practised by the actuary and engineer differs substantially from the public perception of the same risks. In several longestablished activities there is a remarkably stable, and presumably socially tolerated, accident rate. In newer and more extensively hazardous activities political control, social toleration and public perception of risk interdepend in ways which require further exploration.

The collective expression of attitudes towards energy systems governs demand and hence cost, which combines with other factors to shape energy policy. For example, in the national debate over nuclear power, where decision makers either share the public's anxieties about costs and safety or are expediently responsive to them, there is a constant threat to political acceptance. The paper describes how perceived risks are one of the costs of all technologies and a brief summary is made of research on comparative risk perception. This confirms the wide disparities often observed between lay and expert risk assessments and provides some explanations. When attention is focussed on particular hazards, the concept of attitude becomes more appropriate than risk perception because choice behaviour is determined by overall evaluations and these are a trade off between perceived risks and benefits. Each of the latter is acquired from two overlapping classes of received knowledge, i.e. factual information (e.g. nuclear power comes from the fission of uranium atoms), and beliefs (e.g. nuclear power will create/reduce employment). In addition, the attitude acquires emotional associations and behavioural dispositions, forming an organised complex based on the environmental object. This structural approach facilities the “unpacking” of public attitudes towards energy systems into their constituents and this is essential for understanding, for consultation and for inducing attitude change.

Energy requirements in primitive societies in the past are estimated and compared with present energy requirements in the Third World. The interaction between the energy policy of the industrialised countries and fuel availability in the Third World is outlined. Conservation and substitution in industrialised countries are discussed. The different patterns observed in Sweden, France, Japan and the United Kingdom of the behaviour of the ratio of electricity consumption to fossil fuel consumption in recent years is detailed and interpreted. Attention is drawn to some very successful examples of electro-utilisation in Britain. Finally the question is raised of the Scottish economy's response to the opportunities presented by the combination of electro-utilisation and computerisation.

Heat pumps allow the reuse of what might otherwise be waste heat by upgrading such energy to useful temperature levels. Industrial applications to evaporation, distillation and drying are briefly described, together with heat pumps' place within process integration, using examples from the Scottish distilling industries. It is shown that heat pumps are another tool available for energy use optimisation.

Our President, Sir Alwyn Williams, asked me to act for him in this last element of our Symposium and he stressed that I should tell you how unhappy he was to be absent today.

I found myself reflecting on some possible reasons for the invitation to me to deputise. The most obvious is perhaps my seniority as a Fellow of the Royal Society of Edinburgh. I have been a Fellow for almost forty years. In addition, and more pertinent to my immediate task, for over fifty years I have been involved in research, or close to research, in nuclear science and particularly concerned with research on penetrating radiation. I trust this qualifies me to discuss some important trends.