The CECRE: supervision and control of wind and solar photovoltaic generation in Spain

High penetration of renewable technologies, especially of wind and solar photovoltaic, has added further requirements to the control and supervision of power systems. In particular, their dispersion and their non-manageable variability involve the need to increase the attention and readiness to act of power system operators. In order to cope with these challenges in an efficient manner, control centers must be equipped with tools that automate processes in order to aid operators. One example of such a control center is the Spanish TSO's CECRE, equipped with tools and communication capabilities to supervise all the commercial wind and 60% of the solar photovoltaic generation installed in the Spanish peninsular system. In this system wind energy accounted for 16% and solar for 2.5% of the total electrical energy produced in the year 2010 and is one of the systems in the world with the highest non-manageable renewable energy penetration levels. In addition, the CECRE checks whether the real time generation scenario of these technologies is admissible and issue limitations as set-point to each single plant when the technical constraints detected can only be solved by means of reducing the non-manageable renewable generation. This paper describes the tools involved in this process and how the three presently possible types of constraints to integration are managed: congestions either in the transmission or distribution system, generation trips due to voltage dips and off-peak power balance feasibility.