• Dipl.-Phys. Gregor Czisch (ISET)

• Abstract

Diminishing natural resources and global climate change are threatening the peaceful course of human development. A fundamental prerequisite for alleviating these dangers is to convert our energy system to renewable generation technologies that neither consume exhaustible resources nor degrade environmental quality despite continuous operation. Therefore also the questions have to be answered how the future electricity system should be structured, which techniques should be used and, of course, how costly the shift to a renewable electricity might be. This also raises the question how far we can get with the existing technologies and what costs are to be expected if one applies them at their today’s costs, as a worst case assumption. It is apparent, however, only taking into account currently available technologies at their actual costs would constitute a worst-case cost assumption, since future developments will unquestionably improve economic performance. But on the other hand it is a conservative approach not overstressing the phantasy with optimistic cost assumptions and therefore it is resulting in a sound basis for further considerations. These questions have constituted the focus of a study to determine the optimum cost of an electricity supply realized for Europe and near-proximity Asian and African regions, an area with 1.1 billion inhabitants and an electricity consumption of about 4000 TWh. The approach includes the option of supplying electrical energy to national economies not only or mainly from domestic resources but likewise in cooperation with neighbouring countries and distant regions using transmission systems to interconnect all participants within a wide-supply area containing huge renewable energy resources. The freedom for international cooperation between the nations opens up for synergetic benefits. Many of the nations within the area of consideration are emerging nations bounding on Europe with renewable potentials far in excess of national demand. Due to this circumstance, the possibilities of wide-area interconnection promise unprecedented economic and technical benefits for all participating nations. The investigations have confirmed that a totally renewable electricity supply is well within the range of current technology, delivering the electricity at costs only slightly above the current cost of electricity even if future equipment cost reductions are neglected.

These findings have resulted from a computational optimisation process determining the system configuration as well as the temporal dispatch (on a annual three-hourly basis) of all power plants and other components, thus establishing a minimum-cost system on a very detailed basis. The resulting optimal configuration is a system dominated by wind power that incorporates generation at good wind sites throughout the entire supply area. A HVDC (High Voltage Direct Current) transmission system connects these wind sites with the centres of demand while also integrating existing hydropower storage facilities, thus providing backup capacities that are enhanced by regional biomass power and given additional support by solar thermal electricity production.

Other system configurations have been determined for scenarios with reduced investment costs for various technologies (e. g. Photovoltaics). Further scenarios demonstrate the influence of possible new technologies or of particular restrictions imposed, for example,
on transnational electricity exchanges. The purpose of these additional scenarios is to obtain a broader view of various possibilities for a future electricity supply employing renewable energies and thus to provide a basis for political decision. The scenarios show that the shift towards a totally renewable electricity system is much less a technical or economic problem, but instead almost entirely a matter to be resolved by the necessary evolution of political attitudes and subsequent political decisions.

The most important insights derived from this study have been:

1. ) An entirely renewable and thus sustainable electricity supply is possible using current

technologies.

2. ) The costs of electricity need not to lie far above today’s costs even if very conservative

assumptions are made; however, the costs are dependent on the future system configuration, and could be reduced by ongoing technical progress, or be negatively influenced by wrong energy policies.

3. ) There is more than enough evidence to justify a confident call for a comprehensive

transition to a sustainable electricity supply, bearing in mind that a broad variety of solutions is possible.

4. ) A Transeuropean renewable electricity system would simultaneously enable the

realization of a combined strategy for developmental assistance and climate protection as a win-win arrangement for all participating states.