The invention relates to a regenerative energy system comprising a first energy producer and a second energy producer. The object of the invention is to improve the environmental compatibility of electrical island networks. There is disclosed a regenerative energy system comprising a first energy producer whose energy production is dependent on the weather and/or the position of the sun, wherein the first energy producer has a generator, by means of which electrical energy is produced, which is fed into an electrical network to which a plurality of consumers are connected, and a second energy producer which has a generator and an internal combustion engine connected thereto, wherein the second energy producer has a tank with fuel which when required can be fed to the internal combustion engine, wherein an installation is adapted to produce the fuel from renewable raw materials and the fuel production installation takes electrical energy for operation thereof from the first energy producer in particular when the first energy producer can produce more electrical energy than the consumers connected to the network consume and/or there is an energy demand from the network to the first energy producer system, which allows the feed of energy to a second energy producer.