Abstract: Methods and systems of managing electric energy delivery and/or commerce. One of the methods comprises providing a plurality of power sell offers of a plurality of first consumers each connected to an electric grid, providing a power purchase offer of a second consumer connected to the electric grid, selecting at least one of the plurality of sell offers of at least one of the plurality of first consumers according to the power purchase offer, and billing the second consumer according to the at least one selected sell offer so at to allow crediting the at least one first consumer.