MARES Real Time Automatic Control for PSH in Small Isolated Systems




Red Eléctrica de España


Red Eléctrica de España (REE)’s tool MARES is a real time monitoring tool based on automation algorithms developed in order to maximise the penetration of renewables while assuring the security of supply in an isolated system on the island El Hierro.



  • Maximise the amount of renewable energy that the is able to be fed into the El Hierro power system in a system-safe way
  • Minimise the risks associated with unpredictability of wind-power that could trigger important incidents in the power grid and island-wide blackouts
  • Develop a self-made automatized solution that suits the challenges faced by the island


Main information:

The island of El Hierro supplies part of its demand out of a unique power plant - a wind park linked to a pumped hydro storage system. The wind power is fed in when available. In times of oversupply water is moved to a storage reservoir in order to be used to generate electricity on demand.

The software tool MARES is employed to monitor this interaction, optimise the management process performed by the operator and minimise the response time. The ‘Real-Time Automatic Management’ tool is based on the idea that automation, real-time monitoring and fast-response are key to achieving the integration of high shares of renewables in a frail, isolated power system. As a result, the integration of renewable energy has moved from 2% in 2014 to currently over 20% on average, and even reached a peak of 50% in February 2016 when a continuous 40-hour period with 100% renewable demand coverage was reached. The generated renewable energy replaces electricity traditionally produced by diesel generators.

During the development phase of the project, the “test-bed” was the power system itself. Since the implementation no major grid discrepancy occurred. Dispatchers at the control centre are evaluating the tool performance continuously, providing feedback and enhancement proposals.

Further benefits have been identified beyond the increase of renewable penetration: the optimisation of dispatchers’ daily tasks, a cleaner environment, a reduction of system costs and an increase in tourism.

Additional information:

Red Eléctrica de España (REE) is the Spanish transmission operator. REE connects 45 million people with electricity, aided by a workforce of 1,700 people. Its mission is to guarantee the correct functioning of the electricity system at all time.