Size Optimization of a Microgrid with Large Penetration of PV and Battery Energy Storage System, 11th IRES Conference, 2017, Dusseldorf, Germany

Microgrids (μG) are an emerging and promising concept for the integration of distributed Renewable Energy Sources (RES) into the power grid by introducing local coordination of controllable distributed energy sources. The University of Cyprus (UCY) plans to evolve the whole campus into a μG with a 10 MWp PV and respective Battery Energy Storage System (BESS). The campus is ideal for a μG because it is connected to the national grid through only one Point of Common Coupling (PCC). The μG will target, among others, the reduction of the UCY electricity bill (e.g. by improved time of use and self-consumption) and will provide ancillary services such as voltage regulation at the PCC. This paper presents an analysis on optimizing the required PV power and BESS size (power and energy), control and technology based on the University’s load profile and the solar insolation in Cyprus. Furthermore, the cost of the proposed solution and operational reliability / flexibility of the system are compared for a centralized (single BESS for the whole campus) and distributed (one BESS per faculty building) storage solution. The imported and exported energy from/to the grid is priced based on the net-metering scheme that is currently in place in Cyprus. In addition to the flat net-metering tariff, the energy management system will utilize a simulated time of use tariff (Peak, Off-Peak, Intermediate) aiming to achieve peak shaving during peak hours by the use of PV and stored energy from off-peak hours. It is planned to analyse and determine the optimum BESS size and technology based on the tariff scheme, load and battery capital cost. It is therefore imperative that the optimum size and technology of the BESS is obtained in order to avoid a long payback period and to meet the UCY campus requirements