[MUSIC] Hello, the power curve are essential to estimate the electricity production from a specific turbine. A power curve shows the relationship between turbine power and the flow speed at the hub height. It is generally calculated by numerical methods for a uniform and steady upstream flow. However the upstream flow is generally unsteady and contains turbulent fluctuations. Modern turbine could react to the flow fluctuation in less than ten seconds, and such fluctuations could significantly affect the power curve. We will first decompose the velocity as the sum of the steady flow, V0 plus its temporal fluctuations v(t). The mean kinetic power of the upstream flow will depend on the temporal mean of the cubic power of the velocity. We then decompose the cubic velocity according to the binomial theorem, and we get, and if we perform temporal averaging and assume the temporal symmetry of the turbulent fluctuations, we get the following correction. The impact of the unsteady turbulent flow and the kinetic power will depend only on the root mean square of the turbulent velocity fluctuations. We can then use the turbulent intensity TI. We choose equal to the root mean square of the velocity fluctuations over the mean velocity, the zero. For turbulent intensity of 25 person, we could expect a significant increase of the output power up to 7%. However, here we assume that the turbulent intensity do not affect the turbine efficiency which is not the case. Indeed, if the turbine experience large and rapid variation of the twist exerted by the flow, its efficiency will be reduced. Hence, if we look at the impact of the turbulence intensity on the power curve. At slow speed, the increases in the upstream kinetic power will be dominant. Why? For a larger speed, our own rated speed. The global impact will be negative, and it reduces the output power. To sum up, the output power curves characterize the turbine efficiency, and mainly depends on the turbine technology, but not only. The turbulence intensity of the up stream flow which depends on local conditions will mainly affect the amount of kinetic power available at low speed. At higher speed, it is mainly the ironically called the efficiency of the turbine blade that will be reduced by the turbulent situation. Thank you.