32 the generator 32 is now in generator mode and it continues to operate as a pulse former and it also supplies the additional required energy by appropriate dimensioning of wind energy system 10 it is possible on average for enough energy to supply the loads to be provided from wind energy the usage of internal combustion engine 30 and the associated fuel consumption can thereby be reduced to a minimum fig2 shows a variant of the isolated network shown in fig1 the structure essentially corresponds to the solution shown in fig1 the difference is that here no internal combustion engine 30 is associated with second generator 32 which acts as a pulse former internal combustion engine 30 is instead connected to an additional third synchronous generator 36 which can be turned on as needed second synchronous generator 32 thus constantly operates in motor mode as pulse former reactive power producer short circuit current source flicker filter and voltage regulator fig3 shows an additional preferred embodiment of an isolated network in this figure three wind energy systems 10 forming a wind park as an example are shown with synchronous generators each connected to a rectifier 20 the rectifiers 20 are connected in parallel on the output side and feed the energy produced by wind energy systems 10 into a dc link 28 also shown are three photovoltaic elements 12 each connected to a step up converter 22 the output sides of the step up converters 22 are likewise connected in parallel to dc link.