Techniques for Electric Power Systems with High Penetrations of Renewable Non-Thermal Generation

The recent EU Directive on renewable energy commits the UK to binding targets for renewable energy. By 2020 the UK must find 15% of its primary energy from renewable sources: these being basic energy forms including naturally available fuels or renewable energy sources, but not derived energy forms like electricity or hydrogen which are assessed in terms of their primary energy input. The maximum contributions that are likely to be met for renewable transport fuel and heat by 2020 are widely agreed to be 10%. This leaves renewable energy electricity generation to make up the balance; but because of the limited efficiency of electricity generation from primary energy sources (fuels) this means that the proportion of renewable electricity in the generation mix must be much higher to meet the primary energy target. It has been calculated by the UK Energy Research Centre (UKERC), that more than 40% of the UK's annual electricity generation would need to come from renewable energy sources like wind, photovoltaics (PV), biomass fuelled generation and the emerging new marine energy sources of wave power and tidal stream. In the longer term the Severn Barrage could make a substantial contribution, but this could not be operational in time for 2020. What is clear is that the penetration of renewable sources like wind will need to increase dramatically over the years to 2020. Because the main renewable sources of wind power, marine energy and PV produce power that varies in time reflecting the time changing availability of the natural resource, they cannot be treated like conventional thermal generation sources (coal, gas, oil and nuclear) which together are controlled to match demand. The 40% or more penetration anticipated is far higher than can be absorbed without significant change to the electricity supply system and its operation, and is correctly perceived by the electricity utilities as certainly challenging and potentially disruptive. If 40% of electricity is to come from such time varying renewable sources, at times of low system load and high renewable energy generation, the instantaneous penetration will be far higher. If the reliability and quality of the supply is not to be jeopardised, a radical change in the way power systems are designed and operated is unavoidable. An aging asset base means the industry is now engaged in planning a major tranche of new generation plant and upgrading the transmission and distribution infrastructure. This provides a major opportunity to design for incorporation of non-thermal distributed generation, making use of new technologies such responsive demand to facilitate this transition. The proposed Platform grant research will be focused on developing new methods for designing and operating power systems that can successfully absorb such high levels of non-thermal, renewable generation, and on the way the market mechanisms that underpin investment might need to change.The research work will be undertaken closely with the electricity supply industry; this is essential if confidence is to be created around these new ways of working in time for implementation to facilitate meeting the 2020 target.