Multi-services storage plant at a domestic customer´s premises: Effect of simultaneous requests

The progress in performance and cost of lithium-ion batteries, and the research and experiments about smart grids bring us to consider the introduction of low range storage devices (several kW; 1/2 hour to several hours) in the distribution grid. In particular, storage could be connected to the LV grid, in the premises of a client or close to him. We studied two use cases of domestic storage, by electrochemical battery, which would contribute to two or three services, either regulated or deregulated. Both use cases could be profitable beyond 2020: . One around voltage smoothing, completed with reduction of outage duration and arbitrage on the energy market . One around primary frequency regulation, with the same complementary services. The use case around primary frequency regulation seems to have a greater potential in storage installed capacity than the use case around voltage smoothing. Nevertheless, the simple addition of the values of each service raises the problem that possibly, at the same time, two services or more will request to use the device. So we have to define a priority between the services and to calculate the loss of value for the services which have not priority. More, in the use case around frequency regulation, we prefer withdrawing the service of arbitrage and keeping the outage duration service as only complementary service. In both use cases, the loss of value appears to be quite limited. In particular, the outage duration service has naturally a simple way of coexistence with other services: it occurs only when the client equipped with storage undergoes a power cut. More generally, it is consistent with the fact that both use cases have been researched and defined in order to minimize the risk and the effect of simultaneous requests of the storage device by several services.