Abstract: There are provided a method and a device for providing aggregate offers of electrical energy, on the basis of a plurality of loads and/or of sources of customer sites of an electrical network, the method including the reception of information relating to a provision of electrical power arising from the loads and/or sources of each customer site, and the determination of elementary blocks of electrical power, each elementary block being defined in two dimensions by a duration and an electrical power, followed by a spatial arranging of elementary blocks to obtain an aggregate block defined by an electrical power and a duration complying with a constraint selected from among a setpoint power or a setpoint duration, the spatial arranging step implementing a procedure for optimizing spatial filling of a block defined by a maximum power and a maximum duration, by elementary blocks.