In the near future, the electricity supplied by their wind turbine or their photovoltaic panels will be directly injected into the network or into the energy circuit of their house, residence or factory. Thanks to smart metering, consumers and grid operators will know precisely the consumption of electricity. a site or a home. Energy suppliers will therefore be able to offer consumers new offers according to their consumption profile, as well as new services for energy efficiency or energy demand management. It is clear smart grid  has advantage for the consumer. However will this smart grip decrease the price  of energy ? How far? What evolution for the next 50 years ?