The value of weather forecasts for optimally placed wind and solar electricity generators

Michael Lehning ^1,2* Jérome Dujardin ^1,2 Albin Cintas ¹

• ¹ Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland
• ² WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland

As many societies are switching towards renewable wind and solar energy generation, the need to address the problem of high volatility of these generators gains importance. Given the spatio-temporal variability of weather and therefore production, an optimal placement of new installations with respect to demand matching can be found for average weather (or climate) in a grid environment. At the same time, with ever increasing accuracy of weather forecasts, the possibility of predicting wind and solar production for the coming days becomes a realistic planning option, useful for consumers and producers of electricity in a given market. Using the example of a hypothetical future (2050) Swiss electricity system in which demand is served mainly by existing hydropower, wind and solar PV, we show the value of considering weather forecasts in the system-wide, dispatchable hydropower operation. Constructing a scenario, in which the future weather is unknown and comparing it to a situation with a perfect weekly forecast, we show using the OREES optimal powerflow model that the weather knowledge significantly reduces required import of electricity. The weather forecast leads to savings of 36 % in import costs and overall to a much more stable and less volatile grid operation with reduced energy transfer also at a regional level.