By Andreas Armenakis and Nikolas Chatzigeorgiou
One of the key driving elements for the evolution of energy systems around the globe are new developments, regarding Renewable Energy Sources (RES), power electronics and smart grid technologies.
However, deploying more distributed energy resources for electricity decarbonisation goals increases the difficulty of maintaining a stable and reliable grid. These intermittent sources, particularly wind and solar, are not always located close to the point of consumption and do not always coincide with the demand.
Cyprus has the highest solar power potential in the European Union, but currently imports most of its energy. Only around 10 per cent renewable energy share keeps Cyprus on track to reach the target (16 per cent of gross final energy consumption) for 2020. According to the Cyprus Renewable Energy Roadmap, renewable energy could provide 25 to 40 per cent of total electricity supply in 2030. Storing excess energy in battery systems until needed could be a way of addressing grid congestion, improving grid reliability and enhancing the evolution of energy systems.
Today battery storage is a minor part of the energy industry, but developing fast as well for homeowners connected with solar panels, as for larger battery parks connected with the grid. Driven by necessity, Cyprus is learning to squeeze more out of its energy system and much of that learning is happening between the University of Cyprus (UCY) and the Electricity Authority of Cyprus (EAC), where researchers and engineers have led the way for new techniques in the energy sector.
In order to develop an optimal policy for the effective integration of energy storage systems, the European project StoRES (Promotion of higher penetration of distributed PV through storage for all) supports pilot installation in Cyprus, Greece, Italy, Portugal, Slovenia and Spain. The main objective of the project is to boost photovoltaic (PV) self-consumption in the Mediterranean region, while solving market, technical, grid and tariff issues without compromising grid stability and reliability.
In May 2018, a 30 kW/50 kWh energy storage system was connected to a conventional distribution substation in Nicosia. It is the first important step for connecting electricity storage systems to the distribution network in Cyprus. This system (named Community Pilot) consists of state-of-the-art high-voltage lithium-ion batteries. The battery system provides services to the distribution network such as power balancing, network and frequency support, as well as services that stabilise and protect the seamless operation of the network and are considered essential for modern power networks.
In Germany, dropping cost of PV panels together with higher grid costs have generated more interest in battery storage. But although battery costs have come down dramatically, there is still a long way to go before they become widely embedded in the grid.
Furthermore there is a clear mission: optimise the utilisation and integration of renewables, by fast absorbing or injecting power, in order to stabilise and secure the utility grid. The challenges for the EAC portfolio goals is to identify related weak points on the grid and install safe and reliable energy storage systems. EAC has a long experience in performing grid studies and will be in a position to determine the optimal storage technology and its size for each application.
As we know, the battery storage market for grids, homes and cars is growing very fast and the regulatory environment in the EU will be ready soon. The social pilot installation in Cyprus ended successfully providing the opportunity to interact with real battery systems and gain knowledge about their operation.
As this is considered the first attempt to integrate grid-connected storage systems in Cyprus, valuable lessons with regards to the behaviour of battery systems have been learned towards establishment of a standardised methodology of integrating storage systems to the grid. This work has received funding from the European Union’s Interreg Mediterranean research and innovation programme under the project StoRES.
Andreas Armenakis is distribution system operator at the Electricity Authority of Cyprus, Nikolas Chatzigeorgiou is a member of FOSS Research Centre for Sustainable Energy at the University of Cyprus