The production of energy requires specialized structures for the generation and transmission of energy in different forms (mostly electricity). These specialized structures, such as cooling towers, transmission lines, switchgear, charge halls or tall chimneys, are all susceptible to analysis of a similar form to that used for other structures. In this case the characteristics of the structure and the way in which they dispose of vibration energy is all that is necessary to obtain a good estimate of the state of health of the structure. This information can be used to assess whether there is a gradual downgrading of performance over a long period. There are also structures that generate energy by methods other than burning fossil fuels (such as wind turbines). These structures can also be assessed for their stability and for ageing.