Co-optimisation of wind and solar energy and intermittency for renewable generator site selection

Sites for the construction of wind and solar farms have typically been chosen to maximise total energy generation of an individual site, but rarely consider the intermittency of the renewable resource available at each location. As more renewable generation is added to electricity grids around the world, this intermittency is rapidly becoming a major factor constraining the volume of renewable generation that can be added cost-effectively, as additional fast-response storage or dispatchable generation must compensate for periods of low renewable generation. We present a statistical approach to selecting wind and solar generation sites that assesses energy and intermittency of individual wind, solar and co-sited wind plus solar farm locations, allowing energy and intermittency to be given weight when selecting sites for new generation. A new multi-objective pareto-front approach to identifying high-performing renewable generation sites that allows for optimising multi-site selection using the median (energy) and median absolute difference (intermittency) of historical weather resource is proposed. This technique is then applied to a 30-year, hourly, Australian weather reanalysis dataset to show the potential improvement over the fleet of wind and solar farms currently operating in the Australian National Energy Market. Finally, an analysis of potential sites for optimal offshore wind and combined offshore wind and solar is presented. The proposed wind-only and solar-only sites show an average energy increase of 9% (solar, 67 sites), 28% (wind, 50 sites) more energy for the same level of intermittency, as compared to the existing generation sites. Three existing combined wind and solar sites were compared to the best three proposed sites, which showed a 3-16% energy increase for the same intermittency, or a 2-11% intermittency decrease for the same energy generated.