SIREN is a three-year research project funded by the Croatian TSO - HOPS and Croatian Science Foundation. The total value of the project is 2 million kn (app. 265.000 Eur). The project has started on December 1st, 2015, and will end on November 30, 2018.
The project leader is Prof. Hrvoje Pandžić.

PROJECT ABSTRACT

Large-scale integration of uncertain and intermittent renewable sources, such as wind, is a major challenge for system operators. In Croatia, the transmission system operator (HOPS) is obliged to accept the entire output of renewable generators, regardless of the time and quantity of the generated electricity. This imposition presents a large stress to the operation of the Croatian transmission system: the flexibility requirements are much higher, the congestion management needs to be refined and the system planning and operation procedures need to be updated.

One part of the project will be directed to updating the current and developing new strategies of HOPS’s system operation practices. Wind power plants’ characteristics, their expected output and effects of uncertainty will be examined. Both transmission system and generating units’ adequacy will be assessed in order to determine the flexibility requirements at different operating states of the system. This will be done for different levels of wind integration.

Another part of the project will investigate the benefits of energy storage units in transmission system. Besides the potential for construction of conventional storage units, i.e. pumped hydro power plants, the potential for utilization of battery energy storage and flywheels will be assessed as well. The usage of these storage units for arbitrage, storing energy from wind power plants, corrective actions after a contingency, voltage support, and deferment of investments in transmission lines and generators will be investigated. A price of storage at which this kind of installations become economically viable will be determined. Also, regulatory aspects of large-scale integration of storage will be investigated and proposed.