Where Next for the Supergrid?

Feb 20, 2011 - David Appleyard - renewableenergyworld.com

Transmission is the talk of the town right now throughout Europe. There are various plans currently under discussion that could see a radical transformation of the region's electricity transmission system.

These moves are being prompted by the realisation that if Europe is to meet its 2020 targets of 20% renewable energy penetration (fuels, heat or electricity), a major contribution will have to come from the electricity sector. This strategy certainly presents a number of significant challenges, as an increased focus on offshore wind will create new challenges to delivering the electricity to load centers.

A new generation of transmission system will not only allow significant quantities of offshore wind to be delivered, but will also enable the development of a far more liquid and physically-interconnected European energy sector. This too has advantages that will enable the EU to more easily reach its energy policy objectives. For instance, a fully interconnected energy sector will, in the future, be able to balance volatility in the UK’s large offshore wind portfolio with pumped storage capacity from Norway’s extensive hydro power portfolio.

Indeed, in December 2010, European transmission system operator group ENTSO-E signed a Letter of Intent as part of the North Seas Countries Offshore Grid Initiative, which pledges to facilitate the strategic and coordinated development of power grids both on and offshore.

At the time ENTSO-E president, Daniel Dobbeni observed: "The North Seas Countries Offshore Grid Initiative is a significant step in the direction of regional cooperation with a shared vision, concrete objectives and an ambitious, but also pragmatic action plan. It is based on a common understanding on the potential of the renewable energy sources of the North Seas in contributing to the EU Energy Policy goals."

The European Commission recently presented its energy infrastructure priorities for the next two decades, which it says are aimed at making networks fit for the 21st century.

"Energy infrastructure is key to all our energy goals: from security of supply, the integration of renewable energy sources and energy efficiency to the proper functioning of the internal market. It is therefore essential that we pull together our resources and accelerate the realisation of EU priority projects," said European Commissioner for Energy Günther Oettinger in a recent comment on the move.

ABut are massive and costly infrastructure projects the only possible solution? And do such projects need to be financed by the public purse?

By way of example, Norwegian utilities E-CO Energi, Agder Energi (AE) and Lyse, Sweden’s Vattenfall, and a Scottish and Southern Energy (SSE) are investigating the feasibility of building a high voltage electricity link between the UK and Norway. The HVDC link will have a capacity of up to 2 GW and will interlink flexible hydro with intermittent energy sources such as wind power.

And, in a recent report commissioned by Greenpeace from specialist engineering consultancy Energynautics, the authors concluded that smart grid management and control technology – together with a transmission network – can play a major role in reliably balancing the supply of variable renewable energy with demand across the continent.

Furthermore, according to an interim report from the National Electromobility Platform’s Charging Infrastructure and Network Integration Working Group, Germany’s power grid could already handle one million electric vehicles, with the country’s utility industry convinced that the federal government’s objective of having roughly a million electric vehicles on its roads by 2020 would not pose any problems for the grid.

The future development of smart grid technologies offers new opportunities. For instance, by 2020, cable-free inductive charging and higher-voltage direct-current charging will make "fueling" a vehicle faster and more convenient, the report concludes.

Thus it appears that the addition of new types of load (like electric vehicles) and the rapid growth of intermittent generation resources (like renewables) are fundamentally transforming the energy system in unforeseen ways.