Autonomous Microwave Sensor for Improved Atmospheric Measurements for Offshore Wind Farms

As of June 28, 2024, Vineyard Wind 1, the first large-scale offshore wind farm in the United States, has 10 turbines in operation, which is enough to power 64,000 homes and businesses. U.S. offshore wind energy project development and operational pipeline reached a potential generating capacity of ~53 GW in June 2023, (US Department of Energy, Office of Energy Efficiency and Renewable Energy 2023). In addition, approximately 10 GW of offshore wind capacity was put into operation in 2023, and the cumulative global offshore wind capacity is forecasted to reach 414 GW by 2032, (World Forum Offshore Wind e.V. 2023).

As wind energy moves toward a full integration within power grids, one of the main challenges faced by the wind industry is a clear understanding of its variability. To better integrate wind power into an electrical grid, a reduction in the uncertainties associated with this power source would be valuable.

Atmospheric stability has a significant impact on the operation of a single wind turbine, as well as on the overall efficiency of a wind farm. For example, for the Horns Rev 1 wind farm, an improvement in the optimized layout which considered atmospheric stability was equivalent to 1.8M Euros in annual revenue, (Guo, et al. 2021). The Horns Rev 1 wind farm is located 14 km off the west coast of Denmark with a rated capacity of 160 MW and consists of 80 wind turbines.

The publication (The International Energy Agency (IEA)Wind Energy Systems Technology Collaboration Programme’s 2023) indicates that the grand challenges in the area of wind energy related to the atmosphere are “increasing atmospheric observations” and “expanding and validating universal predictive capability”. To achieve such goals, more measurements of the atmosphere need to be taken continuously.

Atmospheric stability is defined by the atmospheric temperature and humidity profiles. These are thermodynamic parameters of the planetary boundary layer.

The authors (Collaud Coen, et al. 2014) document that a microwave radiometer observing at multiple zenith angles provides sufficient information for planetary boundary layer height (PBL) determination. The authors state “We conclude that the radiometer is the most robust among the experimental methods under consideration (lidar, wind profiler, radiosondes) and best suited for automatic real time detection of the PBL height. It provides good results under a wide range of meteorological conditions.” The paper by (Cimini, et al. 2013) arrived at a very similar conclusion.

We will introduce a new generation of a microwave radiometer, (Klein 2023), that is autonomously calibrated, provides thermodynamic profiles with improved vertical resolution within the PBL, measures precipitation rate (including snow), and can provide these and additional data every few seconds. This remote sensing technology has the potential to reduce the cost of observations of thermodynamic profiles, help characterize atmospheric stability, help to validate predictive models, and provide more complete information about the status of the local atmosphere where wind turbines operate.

This is a thermodynamic profiler that is built for a buoy installation. It has low power consumption, unattended operations and calibration, and a robust design. This affordable technology can provide timely and high resolution PBL observations and atmospheric stability evaluation under all weather conditions and therefore reduce the uncertainties associated with wind power.

References

Cimini, D., F. De Angelis, J. C. Dupont, S. Pal, and M. Haeffelin. 2013. "Mixing layer height retrievals by multichannel microwave radiometer observations." Atmospheric Measurement Techniques 2491-2451. doi:10.5194/amt-6-2941-2013.

Collaud Coen, M., C. Praz, A. Haefele, D. Ruffieux, P. Kaufmann, and B. Calpini. 2014. "Determination and climatology of the planetary boundary layer height above the Swiss plateau by in situ and remote sensing measurements as well as by the COSMO-2 model." Atmospheric Chemistry and Physics 13205-13221. doi:10.5194/acp-14-13205-2014.

Guo, N., M. Zhang, B. Li, and Y. Cheng. 2021. "Influence of atmospheric stability on wind farm layout optimization based on an improved Gaussian wake model." Journal of Wind Engineering & Industrial Aerodynamics. doi:10.1016/j.jweia.2021.104548.

Klein, M. 2023. Systems for Passive Microwave Remote Sensing and their Calibration Methods. USA Patent 11,567,015 B2. January 31.

The International Energy Agency (IEA)Wind Energy Systems Technology Collaboration Programme’s. 2023. Grand Challenges Revisited. Wind energy research needs for a global energy transition. Report, Boulder, Colorado, USA: International Energy Agency.

US Department of Energy, Office of Energy Efficiency and Renewable Energy. 2023. Offshore Wind Market Report: 2023 Edition. Market Report, US Department of Energy.

World Forum Offshore Wind e.V. 2023. Global Offshore Wind Report. Market Report, Hamburg, Germany: World Forum Offshore Wind.