|June 11, 2009|
EU power lines 'too old to deliver 2020 renewables target'
Ageing grid cannot transfer energy over the long distances demanded by renewable power stations, say academics
Europe's electricity grid needs a radical overhaul if it is to distribute the renewable energy capacity that governments have committed to building by 2020, according to Europe's leading science academies. They argue that the continent's ageing grid infrastructure is incapable of transferring energy over the long distances demanded by renewable power stations, which are often built in remote locations, far from population centres.
In a report for the European Commission, published today by the the European Academies Science Advisory Council (Easac), experts called on national governments to co-ordinate their grids and invest in new technologies such as high-voltage direct current (HVDC) transmission lines to better prepare Europe for a future of green electricity.
"The whole transmission and distribution system needs redesigning," said Mike Sterling, an electrical engineer and fellow of the Royal Academy of Engineering in the UK, who chaired the electricity grid working group on behalf of Easac.
The EU has committed to sourcing 20% of its energy from renewable sources by 2020 but experts said this generating capacity will be wasted unless it can be distributed properly.
"The change in the generating sources is well known and, unless we can get clean coal or nuclear back up again, there will be a dramatic change in the distribution of the energy sources," said Sterling. Renewable energy for the UK, he said, might come from remote locations in the North Sea or off the west coast of Scotland and the power sector needs to work out how to bring that power to the places it is needed.
"We must make major changes to the current delivery systems in the EU and become more co-ordinated if we are to meet these targets," said John Holmes, secretary to the Easac working group, "This report gives the EU Directorate General a blueprint for a brighter, greener future in Europe."
Upgrading the grids in individual countries should be done to common standards, said the report, and eventually the movement of electricity across Europe might even be managed centrally. Any extensions to the grid could incorporate HVDC transmission lines so that electricity could be moved from, say, solar plants in the Sahara to northern Europe whenever there is no wind. These lines are preferred because they lose less of their energy during long-distance transmission compared to standard AC cables, but they are also more expensive to build.
Scandinavian countries potentially have excess capacity in hydroelectric plants that could, ideally, be sold to places such as Germany. If agreements can be made with north African countries, solar power collected in the Sahara desert could be transported up into southern Europe. "In order to do that, you need to design the transmission system so it can cope with the large power flows through existing countries' networks [but] Italy's transmission system is not designed for that, nor is Spain's."
Electricity companies warned a committee of MPs in April that the government was in danger of missing its target on renewables without substantial investment in a new national energy grid.
Last year, EU scientists also proposed a plan for a Europe-wide supergrid that could share Europe's renewable energy resources across the continent. They said the grid could allow countries such as the UK and Denmark ultimately to export wind energy at times of surplus supply, as well as import from other green sources such as geothermal power in Iceland.
The scientists working on the project envisaged that, by 2050, solar power plants in north Africa could produce 100 GW, more than the combined electricity output from all sources in the UK, with an investment of around €450bn. But they also said this could not be transferred to northern Europe without a major restructuring of grid infrastructure in the transfer countries such as Italy and Spain or Greece or Turkey.