Wind turbines are actually surprisingly complex machines with many ways to control the power generation, for all important metrics: voltage, power, frequency, etc.

Essentially the main variables at play are rotational torque and rotor speed, and there’s a lot of ways to control those variables. For example, the rotor can be rotated to face the wind at the ideal angle, or the pitch of the blades can be tweaked. There are also components quite like those you’d find in a car - brakes, clutch, gearbox, etc. which control the rotor speed and rotational torque. All of these systems are intelligently controlled and responsive, and allow very fast response to changes in demand or weather conditions without human input.

Solar panels, similarly, can be angled - commercial solar farms are usually motorised. This is mostly done so the panels can track the sun, making them much more efficient, but it also means they can be angled away from the sun, if need be, to reduce output. In reality, this isn’t really done, because it’s easier to control wind - solar provides baseline power and wind builds on top of that and adds responsiveness.