What does the term NEG (net energy gain), exactly mean?
By net energy gain (sometimes also referred to as energy amortization or energy payback) we mean the time it takes for a solar installation to generate the amount of energy it took to produce the installation. A PV installation on the basis of amorphous silicon has – according to a study by the Technical University of Berlin – a payback time of 17 to 41 months. Crystalline modules have a payback time of a similar magnitude, whereas monocrystalline modules perform slightly worse due to the more costly process. Power stations, however, which run on fossil fuels, can never compete. Study: A solar module generates the amount of energy used for its manufacture within three years. One of the ways to compare different processes is to use, in addition to known criteria such as the cost and impact on the environment, the time it takes to reproduce the energy used to manufacture the installation itself. Example: Large power stations run on fuel, water power or nuclear energy and require consider
