Wind forecasting errors bring great uncertainty to the system operation, since the real-time wind power output may be very different from what is forecasted. Wind generation can increase or decrease its value at a rate that will require that conventional generators adapt their output to follow that ramp to keep the demand-supply balance. The quantification of ramping reserves is addressed in this paper through Monte-Carlo simulations. The model is formulated as a mixed-integer linear quadratic problem with ramping constraints including the startup and shutdown power trajectories of thermal units. The uncertainty in wind power forecasting is captured by a large number of scenarios around a trajectory bid by the wind power generator. The results show that the ramping reserves follow a normal distribution for ramp up and ramp down reserves.