Analysis of massive integration of renewable power plants under new regulatory frameworks

Massive effective integration of renewable energies into the electric grid is an issue in almost all electric power systems. These renewable energy sources (RES) are usually based on wind and solar photovoltaic generation and cannot maintain a power reference due to variations in wind and solar irradiance. Currently the integration of these renewable energy sources is possible in strong power systems due to the support of the conventional power plants which maintain the stability of the power system. In weak networks instead, the massive integration of renewable generation systems could generate stability problems to the power system, so they are being required to provide grid support functions as voltage control and frequency control by the new regulations. Moreover, in order to reduce the uncertainty introduced by these RES, some governments are also compelling these RES to reduce the uncertainty of their generation. The main goal of this is to transform the behavior of the current uncontrollable RES to stable and predictable generation, converting it from variable and unpredictable generation into dispatchable generation. But to achieve this goal the RES have to be supported by Energy Storage Systems (ESS). In this paper two different representative regulatory requirements will be described, analyzing the philosophy of them and proposing solutions to face up to these new requirements, taking into account several factors as the location, efficiency of the equipments, and other technical issues.