A major problem with renewable energy, such as wind and solar power, is that supply is often intermittent, causing fluctuations and strain on the grid system. In addition, the current European grid system is unable to meet rising energy demands and needs to be transformed. Proposals for overcoming these problems include 1) a large-scale grid to transmit electricity from renewable sources over long distances, a 'Super Grid', and 2) decentralising production of renewable electricity from distributed, small installations, such as micro turbines, fuel cells or biogas digesters: a 'Smart Grid'.
The researchers, working under the EU CIRCE project1, suggest that these two proposals could be combined to create the SuperSmart Grid (SSG). This would transmit electricity over a wide area and connect up smaller, distributed generation installations. An efficient SSG would also even out any fluctuations over a wide area. The authors argue that a 100 per cent renewable electricity system is necessary if Europe is to meet its target of reducing greenhouse gas emissions by 60-80 per cent, compared with pre-industrial levels by 2050, (in line with the policy to limit the global average temperature increase to not more than 2°C) and that the SSG would enable this system.
Under the EU Renewables Directive2, imported renewable energy from outside the EU could count towards the European target of 20 per cent of all energy being generated from renewable sources by 2020. Therefore, renewable energy could also come from large-scale solar thermal power plants in the deserts of North Africa, where conditions are more economical for generating solar power.
High voltage direct current (HVDC) technologies allow electricity to be transmitted over long distances with minimum losses, when compared to alternating current (AC) lines. The SSG favours a physically integrated European electricity market, which the authors believe would make electricity cheaper for consumers and the system more reliable. Paradoxically, renewable electricity imported from North Africa is likely to improve energy security because total energy imports would be more diverse, they suggest. Moreover, international electricity trade ensures a more stable supply of imported energy as, unlike oil supplies, the electricity could not be stockpiled or sold on the world market.
Compared to alternative options, the authors believe the SSG benefits from large economies of scale and low running costs, but creates important challenges. At today's costs, initial investments for thermal solar plants in North Africa would be up to three times higher than for similar capacity increases with conventional fossil fuel plants in Europe. The following issues are highlighted in the study:
- The profitability of these investments depends on the renewable support mechanisms and future carbon prices. Currently there is no European support mechanism that would apply to imported renewable electricity, and future carbon prices are highly uncertain.
- Bilateral renewable support mechanisms, such as those between Italy and Albania, are not suitable for imports in quantities sufficient to take advantage of economies of scale, nor for meeting decarbonisation requirements.
- Large-scale imports to Europe are likely to be politically attractive to North African countries, but only if they are coupled with efforts to meet increasing local energy demand, including greater access to modern energy.
- A supporting legal framework is needed to obtain permission for the rights of way of the electricity lines across national and local boundaries.