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Rubrik: Science Life

Round table discussion on sustainable electricity supply
How much nuclear energy does the world need?

Published: 15.03.2007 06:00
Modified: 14.03.2007 22:24
New energy demand scenarios, fear of a possible electricity shortfall and global climate change intensify the discussion: what must a sustainable electricity supply look like and what role should nuclear energy play in it? A round table discussion (1) between ETH Zurich experts and political representatives.

The discussion was led by Martina Märki and Conny Schmid

The International Energy Agency recently published the World Energy Outlook 2006. What do you think of the scenarios described in it?

Jochem: In my opinion the reference scenario has the disadvantage that the sources and consumption of energy are both initially set very high. I think the economic growth taken as a basis is overly optimistic. On the other hand I regard the political variant as too hesitant, more could be done in the energy efficiency area.

Hofstetter: I agree. This Outlook has relatively little relevance to us. For me it would be essential for an alternative scenario to take account of the climate protection remits of climate research. I cannot discern that here, since none of the scenarios prevents climate collapse.

Previdoli: I should like to disagree. I regard the report as important. It provides a good overview of the starting point situation. The message is quite clear: we consume too much energy and we emit too much CO2. However the alternative scenario is not ambitious enough. It would be entirely possible to go further, although that raises the question of political enforceability.

Prasser: This message is clear to me: we must expect more CO2 emissions at the same time as a long-term shortage of raw materials. We must respond to this challenge. In the alternative scenario the study clearly shows the nuclear energy option. The only chance of reducing CO2 emissions effectively at all is the combined use of nuclear energy, renewable sources and efficient energy utilisation.

Horst-Michael Prasser, full Professor for Nuclear Energy Systems at ETH Zurich

Nuclear energy as the saviour of the world’s climate? Mr. Hofstetter, what is your attitude to that as an environmentalist?

Hofstetter: We have recognised the reality since Chernobyl. Since then the advocates of nuclear energy have failed to give us an appetite for nuclear energy. Realistically, though, it must be assumed that new reactors will be built in some countries, mainly fast-developing nations. Nuclear energy currently provides only 2.5% of the world’s energy consumption. Nuclear energy will not solve global energy problems either now or in the future.

Prasser: The question is whether that should worry us. We are now talking about a political challenge. Of course politics must take people’s security needs into consideration. However, I suggest that the technological progress made by nuclear engineering is not being properly appreciated. When we look at the scientific and engineering aspects, nuclear energy is not the same as Chernobyl. It is well known that we were dealing with a reactor that did not conform to the design principles even then. A very great deal has happened in the safety arena since Chernobyl. There are ways of preventing core melt-down even if more safety systems fail than the design provides for. If that is unsuccessful, there are also ways of containing core melt-downs within the building, and even if core melt-down can no longer be controlled there are still ways of minimising its impact. Of course it is for the electorate to decide, but the nuclear engineering industry is ready and can offer powerful options.

Jochem: I agree with you. Nowadays we can probably exclude the risk of operating new reactors. However, the real problem is no longer the operating risk, but that of proliferation. Just think of Pakistan, India and Israel, who have already gained independent capability. Now they are being joined by Iran und North Korea. The real question is how secure is the international protection against political chaos in such countries that have now acquired atomic weapons or could acquire them.

Hofstetter: Unless and until private insurance companies are willing to insure all the risks of nuclear energy we obviously have a problem. In fact one of the reasons why nuclear energy plants are being built in only a few countries is because it needs a strong nation that is willing and able to accept this additional risk. We would be well advised to ensure that nuclear energy plants can only be built in such countries. When discussing the technology we must not forget that reactor accidents up to now were always attributable to human failure. The engineering may improve but humans will not. On the subject of nuclear weapons I should like to quote Al Gore, who said: “In the eight years when I was in the White House, every single nuclear weapons proliferation problem that I encountered was associated with a reactor program.

Prasser: I see only a partial link between atomic weapons and nuclear energy. Throughout the world atomic weapons were built using enrichment plants and reactors that made no contribution to energy use. If a government decides to aim for nuclear weapons capability, that government will find technical ways and means to achieve it. I think it is most disturbing if that results in a civilisation allowing itself to be denied an energy source that could be important for its survival.

Previdoli: Basically I should like to beg that individual energy sources should not be played off against each other. We must go forwards on all fronts and must exploit every available source of energy. In my opinion the most important action is quite clear: we must increase energy efficiency in all areas. We have large economic potential there. Then we must find some way of financing renewable energies. The solutions must be ecologically, socially and politically justifiable. When that has been done and the waste disposal problem has also been solved, nuclear energy will also become an option. At any rate the electorate should also have the opportunity to choose this option.

Jochem: But the central question is which options do I have to avoid CO2, and what do they cost?.

Mr. Jochem, if you say that nuclear energy is not the best option for that, which option do you recommend and how realistic is it?

Jochem: Nuclear energy accounts for about 5% of primary energy and it takes about 50 years before a primary energy source reaches its maximum market share, which for nuclear energy is probably 20%. That is an annual CO2 reduction of 0.3 percentage points at most. That means nuclear energy makes only a relatively small contribution to solving the CO2 problem. We can move many times faster than nuclear energy by using energy efficiency measures where we achieve an annual CO2 reduction of one to two percent. That means energy efficiency is the central partner, whatever human beings do.

Previdoli: That is also clearly apparent from the IEA’s alternative scenario, which states potential CO2 reductions of 10% for nuclear energy, 12% for renewable energies, 13% through more efficient energy distribution, 29% for efficiency in the electricity area and 36% for increased efficiency in the use of fossil energy sources. So we can see that we gain a total of 65% through efficiency measures.

Prasser: Nevertheless I think that those nations that are technologically and economically strong have a special responsibility to use nuclear energy. Nuclear energy is a highly capital-intensive technology, but nowadays it is less capital-intensive than renewables. For example the investments needed for wind power are twice as high as for nuclear energy relative to the amount of energy produced per year. The position at the moment is that nuclear energy in developed countries such as Switzerland contributes to an economical supply of electricity, and its environmental compatibility is about the same as for hydroelectric power. With regard to growth rates, much depends on political decisions. Let us not forget that a country such as France has nuclearised its electricity sector almost completely within 30 years. The second thought is the question of the heat supply sector. In conjunction with heat pumps, nuclear energy could cover a significant proportion of this demand with one to two reactors. Today Switzerland is already a world leader there.

Jochem: But the discussion has already progressed much further. The technical colleagues that are here from ETH Zurich say we will be building passive (nearly energy-neutral) houses in future. When you look at the building of passive houses in Germany, it is now really just a question of how quickly new buildings and renovations progress. After that electricity will be used essentially just for the ventilation plant.

Eberhard Jochem, full Professor for Energy Policy and Economics at ETH Zurich

Is our thinking wrong when we argue that there is a threat of an energy shortfall?

Jochem: Switzerland’s energy demand is met 60% by hydroelectric power and 35% by nuclear energy. Those are all long-term investments of at least 50 to 100 years. The following could now happen: Switzerland’s electricity demand is currently increasing. We are now re-investing in two or three nuclear power plants in Switzerland, but we are making enormous progress in energy efficiency at the same time. If the industrialised nations achieve the 2000 Watt society sometime (2) , perhaps around 2070 or 2080, we would then have nuclear power station capacities lying around in Europe that we would no longer fully need.

Prasser: I do not see there will ever be a day when electricity demand declines so much that there is longer a return on investment in nuclear energy. However, I think everyone agrees that we will run into an electrical energy shortfall, certainly worldwide but in Europe as well. Not without reason are the energy suppliers returning to fossil sources such as gas or coal. They have no prospect of filling the whole of the electricity shortfall with renewables, otherwise they would not be looking elsewhere. And they have an investment problem there as well. They will prefer to invest in fossil power stations unless the politicians put the correct framework conditions in place.

Hofstetter: And that is exactly where the EU is taking the appropriate steps with the Efficiency Action Plan, for example. Increasing energy efficiency is the most important tool and is the quickest way to success. The supply of energy through renewable energy sources makes the second largest contribution. In addition, if the capture and long-term storage of CO2 becomes technically feasible, then according to EU planning it could soon become mandatory and by 2020 might already make an important contribution to reducing CO2 emissions. Of course this option would affect the profitability of fossil fuel power stations, which again indirectly encourages energy efficiency and renewable energies as well.

Prasser: We have a situation today in which coal is in the lead in overall economic terms, if indirect costs are not included in the calculation. The cost of a coal kilowatt-hour from anthracite is slightly more favourable than a kilowatt-hour of nuclear energy. This ratio is reversed by sequestering (editor’s note: capture and storage of CO2). We are entering a situation in which the replacement capacities that are supposed to plug the electricity shortfall throughout Europe are all more expensive than nuclear energy. Now you say that in 20 or 30 years we will no longer get any return on investment for a new nuclear power station. That is a glaring contradiction.

Jochem: You are confusing two different things. Firstly there is the question of choosing which technology to adopt for electricity generation. Of course one can consider whether one wants to satisfy the electricity demand with expensive coal and expensive renewable energy sources so as not to incur a proliferation risk under any circumstances. That is a subjective decision by the electorate. There is also a dynamic problem connected with demand and decentralised generation. If the political forces were finally in a position to utilise the potential efficiencies, the industrialised nations would sooner or later pass through a demand maximum, after which the curve would become level. The choice of the technologies – including decentralised electricity generation – is the first thing, the dynamics of the demand is the other.

Previdoli: Precisely, and one must not fill the supply shortfall entirely with big technologies, since if the attempts to achieve efficiency then take effect we would have too much capacity after a couple of years. Jochem: And that’s why the electricity industry must think carefully whether and how much nuclear energy is really needed against the backdrop of the vision of a 2000-Watt society in 2080. By then we would probably need just one power station instead of two. The fact that we will have a combination of various technologies is not in dispute.

You are backing the energy efficiency horse. That’s all very well, but are actions on the scale that would be necessary also politically enforceable?

Jochem: That is a crucial point. Efficiency has one problem that renewable energy sources don’t have: hardly anyone is doing anything about it. Efficiency has no lobby. All the other energy sources are politically acceptable because they have a sexy media image. Energy efficiency cannot be conveyed via the media and is not at all sexy.

Previdoli: I share this opinion, but it is beginning slowly: the International Energy Authority has made energy efficiency a priority topic, the G-8 have declared energy efficiency to be the mega-theme and Germany wants to make progress with energy efficiency during its presidency of the EU. I believe now is a good time to build up a lobby.

Hofstetter: Nevertheless I think there is a lack of political will. This is mainly because of the absence of groups lobbying for energy efficiency in political circles. In the efficiency sector there are scarcely any major facilities with a high financial turnover. That means there are no board seats that can be occupied by people with political leverage.

Jochem: The whole thing is rather more complex. Nowadays the manufacturers of efficiency systems also produce technologies to offer energy. Now if there is no demand from the majority of the clientele for the efficiency products on offer, then of course these producers keep a low profile.

Previdoli: I believe that the energy label is a very important tool by which consumers can at last obtain information as to whether or not an appliance is efficient. If that is not sufficient, one would need to impose consumption regulations.

Prasser: Of course you cannot legislate that in Switzerland people can only buy motor cars that consume 3 litres (per 100 km). That might work, but it might not work. Not working means there would be an upsurge of dissatisfaction that would manifest itself in political decisions.

Jochem: In the long term we must reduce CO2 emissions in the industrialised nations by at least 80%. That means we are talking not of a 3-litre (per 100 km) car, but of a 2- or 1-litre car. Now you say that won’t be politically feasible. Why not? Because the car owner defines himself by his status and by the preferences of his social group, and strives for recognition. The aim must now be to modify the value systems of the layers of society that determine social values. They must be able to say it is cool to have a car that has a maximum consumption of 3 litres/100 km and still basically performs as well as a Bentley. One must change those value systems which currently create a pattern of consumption that is not sustainable even though technologically it would be possible.

Previdoli: The advantage of the motor car is that it is visible. The majority of the energy efficiency areas lack visibility.

Hofstetter: Correct. We have no emotional attachment to electricity. Electricity is not a status symbol unless it is visibly produced on your own rooftop. I think that is a very important reason why solar energy has astonishing potential despite the economic obstacles. It really offers an opportunity to put one’s cards on the table.

The participants

Eberhard Jochem is a full Professor for Energy Policy and Economics at ETH Zurich. He is a member of the German Federal Government’s Council for Sustainable Development.

Patrick Hofstetter is Director of the Climate and Energy Department at the World Wildlife Fund (WWF) Switzerland. He graduated in Mechanical Engineering at ETH Zurich, where he also gained his doctorate in Environmental Science.

Horst-Michael Prasser has been a full Professor for Nuclear Energy Systems at ETH Zurich since April 2006. He works in the nuclear technology plant safety area, concentrating on thermofluid dynamics.

Pascal Previdoli is Head of the International Energy Affairs, Strategy and Policy Division at the Swiss Federal Office of Energy (BfE). He graduated in Economics and gained a doctorate in National Economics, and has published on the subjects of energy, industry and sustainability, among others.

(1 The discussion was published in the February edition of ETH Globe: (
(2 More information about the 2000-Watt society: (

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