A stand-alone renewable-energy generating device which generates electric energy from renewable energy sources, such as the sun or wind, in a stand-alone context. To allow users to asses their contribution to carbon dioxide emission savings, a sensor element that is configured to generate emission savings data representative of electric energy units generated by using a renewable energy device. Further, a clock device is configured to generate a time data representative of at least one of a time and a date specification and unique sensor-ID data are stored in a memory. A processor unit is configured to time-stamp the emission savings data by combining it with the time data. The processor unit retrieves the sensor-ID data to combine them with the emission savings data to form savings profile data. A communication interface is configured to communicate the savings profile data directly or indirectly via a network system.