The potential of energy storage systems associated with PV generation to postpone investments in capacity expansion

Postponement of infrastructure investment is often regarded as a potential benefit of distributed PV generation. However, PV has questionable impact on the postponement of investments for infrastructure capacity increase. This paper evaluates under which conditions and to which extent distributed photovoltaics and energy storage systems are able to aid the distribution system in terms of alleviating the loading of feeders. The methodology consists of a sensitivity analysis, in different demand and generation scenarios, on the impacts that photovoltaic generation and energy storage systems would have in alleviating distribution feeders. In each scenario, the synergy between energy storage and PV generation is evaluated by estimating the amount of energy storage capacity needed to reduce the peak demand to a desired level. Results show that the existence of PV generation may reduce the storage capacity needed (and consequently the cost) to achieve a desired peak demand reduction only if proper conditions are found in the demand curve.