Rotor blade for a wind energy installation

A wind energy installation comprising:

• a rotor (18) which can be driven by wind, comprising at least one rotor blade (22) comprising at least one sealed, gas-tight cavity (28) that is filled with gas, the cavity being disposed within the rotor blade (22), wherein:
• (a) the pressure of the gas within the cavity (28) is greater than or less than the average air pressure to be expected at the point of use of the rotor blade (22);
• and
• (b) the pressure of the gas within the cavity (28) generates a prestressing of the rotor blade (22) that counteracts external forces acting on the rotor blade (22);
• a generator for conversion of mechanical energy produced by the rotor (18) to electrical energy;
• and
• a tower (14) on which the rotor (18) is arranged.

A rotor blade for a wind energy installation, with the rotor blade comprising:

• (a) at least one sealed, gas-tight cavity (28) that is filled with gas, the cavity being disposed within the rotor blade (22), wherein:
• (i) the pressure of the gas within the cavity (28) is greater than or less than the average air pressure to be expected at the point of use of the rotor blade (22), and
• (ii) the pressure of the gas within the cavity (28) generates a prestressing of the rotor blade (22) that counteracts external forces acting on the rotor blade (22);
• (b) at least one inlet or outlet opening arranged in one or more walls (24, 26) which bound the cavity (28), via which the gas is introduced from the outside into the cavity (28), or via which the gas is passed to the outside from the cavity (28), wherein the at least one inlet or outlet opening is arranged in the area of the rotor blade root;
• and
• (c) at least one sensor by means of which a measurement within the cavity (28) is measured, the at least one sensor being selected from the group consisting of pressure sensors, humidity sensors, temperature sensors, and combinations thereof.