Seminar: Jonathan Minz

Energy scenarios envision that generation from regional scale wind turbine deployments will play a significant role in a future renewable energy supply. This generation or technical wind energy potential is estimated by forcing wind turbines deployed over all available areas, with measured or modeled wind speeds. The impact of atmospheric response on generation is fixed to 10% to manage the computational burden. However, this leads to a significant overestimation relative to approaches that account for atmospheric impacts more comprehensively, like WRF. Thus, it is natural to ask how technical potential estimates could be made more physically robust while managing computational expense. I have evaluated the extent to which accounting only for the kinetic energy (KE) removed by the wind turbines to generate electricity can capture the impacts of atmospheric response on generation. Broadly, atmospheric response impact is shaped by KE removal by the turbines and atmospheric stability. I have isolated the relative influences of these factors on the impact by comparing wind speed and turbine yield estimates, variables that underpin technical potential, for a range of realistic and hypothetical deployment scenarios in on- and offshore Germany and USA, estimated using three different approaches - the fixed energy loss, WRF and the simple, physics-based. Accounting only for the KE removal with the physics-based approach captures the variation in WRF estimates better than the fixed loss approach. The agreement is better under unstable than stable atmospheric conditions. At the aggregate regional scale, physical estimates of technical potential are within 35% of WRF estimates while the fixed loss approach leads to an overestimation of around 90%. Despite reductions in technical potential, wind remains significant source of renewable energy within the context of the energy transition. However, the reductions do have cost implications that need to be explicitly evaluated in energy scenario analyses. This can be achieved relatively simply through the simple physics-based approaches used in my analysis.