A new long-term government policy paper promoting renewable energy sources has been harshly criticised by business groups and power companies.
The Swiss Business Federation, economiesuisse, and the Swiss power company association, swisselectric, distanced themselves from the "Energy Outlook Forum" final report, presented on Thursday.
The working group brought together the main actors from politics, business, civil society and the environment to discuss Switzerland's long-term energy policy up to 2035.
The report headed by former senator, Dori Schaer-Born, stresses the importance of energy efficiency. Among the recommendations, it proposes economic incentives to encourage innovation and the progressive introduction of energy-saving regulations.
The paper also emphasises the need to increase investment in renewable energies, which it claims offers the greatest potential in terms of profitability and efficiency.
The lack of capacity in power supply, which is expected to continue despite energy-saving measures or the increasing use of renewable energies, has to be temporarily compensated by existing nuclear power plants and gas power stations, the report states. But any additional carbon dioxide emissions have to be reduced and compensated.
Some experts predict that the Swiss energy supply situation could become acute after 2020 if the country's two oldest nuclear plants close down and supply contracts with French nuclear plants are not renewed. They claim that the supply gap could reach between 10 and 30 terawatt-hours (TWh) by 2030 – between 15 and 33 per cent of total anticipated annual demand.
However, the report's remarks drew sharp criticism from two of the working group participants.
In a statement, economiesuisse said the final assessment was "baseless, premature and one-sided". It also claimed that the Federal Energy Office had wound up the working group unexpectedly.
The federation said it did not give "proper place to the essential conclusions of the intermediary reports", which centre on Switzerland's energy supply problems.
According to swisselectric, the document presented is the "forum president's personal report" which does not pay enough attention to the supply question, and economic, ecological or social issues.
The environmental group, Greenpeace, was generally in favour of the report, but regretted that the question of nuclear power remained vague.
In her defence, Schaer-Born explained that it was impossible to give conclusions that everyone would be happy with. She said she had decided on a personal final report as the government was expecting the document for the end of October in order to study the results by the start of next year.
swissinfo with agencies
Switzerland currently produces some 40 per cent of its electricity from five nuclear power plants and the vast majority of the rest from hydropower.
Total Swiss electricity production in 2004 was 63.5 TWh. 1TWh = 1 billion kilowatts.
The Swiss power industry, while part of the European network, is largely self-sufficient.
However, Switzerland is a major trading centre, with annual electricity imports and exports often totalling up to ten times the European average.