The inhabitants of the island of Tilos, in the Greek Agean Sea, know all about the problems of intermittent electricity supply. But the problem doesn’t lie with the much discussed intermittence of renewable energy sources but an unreliable undersea cable connecting them to diesel-powered generators on the nearby island of Kos. Blackouts are frequent, recently lasting as long as 7.5 hours.
Given the island’s suitability for wind and solar power and its connection to the grid ofanother island, Tilos is an ideal test bed for integrating local scale energy storage in a smart island microgrid. Fifteen partners have therefore come together to study three different scenarios on Tilos: a stand-alone microgrid; partial penetration of renewable energy sources on the island; and a virtually stand-alone microgrid interactingintelligently with the “host” grid. At the heart of the system is a FIAMM battery solution with a total useful capacity of 2.4MWh.
The Tilos case will have wider repercussions. Firstly, within Greece itself because there is about 1 gigawatt of diesel-burning generation dotted around the Aegean Sea, resulting in power costs of about 800 million euros a year, that could be replaced by renewables- based hybrid solutions. Secondly, the project partners are comparing results in Tilos with projects being deployed in places such as the German island of Pellworm.
Another key element of the project will be demand-side management, such as smart meters and controlled hot water storage, supported by training for the local population and studies of how islanders react to their new energy set-up.
“Owing to the fact that the island of Tilos is connected to another, host island, energy management will also consider energy exchange with the host grid to maximize the system benefits,” the project partners state. “That also relates to mainland cases, and can thus support system replication not only under stand-alone mode, but also in a market-integrated environment.”