Technico-economic optimization of a collective self-consumption operation

A collective self-consumption operation (CCA) enables renewable energy producers to sell all or part of their production to consumers located nearby and connected to the same distribution network. This energy community concept has a dual benefit. On the one hand, it enables consumers to reduce their expenses by purchasing electricity at an attractive rate compared with their usual supplier, and on the other, it enables producers to improve the profitability of their investments by selling electricity at a higher rate than if it were injected into the grid.

The development of a collective self-consumption operation requires prior definition of the governance and operating arrangements between the various participants and the organizing legal entity (PMO) in charge of managing the operation. A central element of these arrangements is the allocation of energy between the various participants. This allocation is carried out according to a distribution key, defined before the start of the operation, in which both energy and economic criteria are generally taken into account. Optimization of this allocation key appears necessary to maximize the economic interest for all participants.

In addition, the various energy production and storage facilities involved in the project must be sized as accurately as possible in relation to energy requirements, while ensuring optimum economic profitability for the various participants. Optimization of their sizing must therefore be carried out during the project design phase. Optimal sizing in terms of technical and economic considerations is linked to the way in which the system is managed, both individually and collectively, since energy management strategies define the income and expenditure of community partners. The design phase must therefore take into account both the optimization of sizing and the optimization of energy management.

The aim of this article is to present a methodological approach to the co-optimization of energy sizing and management, at both individual (i.e. within the buildings involved in the operation) and collective levels, with a view to defining a panel of economically viable solutions. The method presented is then applied to a case study to illustrate the results that can be obtained, considering a hypothetical collective self-consumption operation in an industrial-port area. An analysis of the results obtained is proposed, from both an energy and an economic point of view, to demonstrate the benefits of setting up a collective self-consumption operation for the various participants. A sensitivity analysis is also carried out to show the impact of certain technical and economic assumptions on the results.