Conventional energy sources such as nuclear or coal generate energy at a constant rate. Renewables on the other hand fluctuate with the variability in the natural sources from which they derive energy. Such fluctuations are particularly acute for wind and solar photovoltaics. On one hand, such fluctuations threaten the stability of the grid, whereas on the other, matching the fluctuating power production with a variable consumer demand presents scheduling difficulties for grid operators. Understanding fluctuations in renewables is also important for the design of robust smart grid technologies for the future.

In this talk, Professor Bandi will chart out the non-equilibrium character of wind power fluctuations which depend upon the turbulent wind blowing past the wind turbines. Indeed, the spectrum of wind power fluctuations is widely known to reflect the Kolmogorov spectrum of turbulence; both vary with frequency f as f-5/3. Yet it has not been possible to derive this spectrum from the turbine power equation which relates the generated power P to the wind speed v. Bandi will explain the wind power fluctuation spectrum and show it arises from the violation of an underlying assumption in Kolmogorov theory of 1941, with crucial implications for wind power. In particular, every individual turbine feels the influence of the largest length scales of atmospheric turbulence. As a result, turbines within and between wind farms become coupled with each other at low turbulent frequencies over large distances. Consequently, when geographically distributed wind farms feed their power to the electrical grid, the fluctuations remain correlated and smooth out until they reach a theoretical bound that can be deduced from Kolmogorov theory. Bandi will close his talk with a summary of engineering and policy implications of these results.

Cost: Free

To learn more about Professor Bandi and his work, click here.

Areas of Focus: Energy Markets
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Energy Markets
Well-functioning markets are essential for providing access to reliable, affordable energy. EPIC research is uncovering the policies, prices and information needed to help energy markets work efficiently.
Renewable Energy
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Renewable Energy
Lower technology costs and supportive public policies are driving an increase in renewable energy in markets around the world. EPIC research is assessing the costs, benefits, and efficiency of policies...