TILOS

Providing energy to small, remote communities like the Greek island of Tilos can be a complex task, which is often reflected in the price. We spoke to Dr Dimitrios Zafirakis about the TILOS project’s work in establishing a smart energy microgrid on the island of Tilos which, together with communityscale battery storage, will help more closely match renewable energy supply to demand

The Greek island of Tilos is located in the southern Aegean Sea, roughly midway between its larger neighbours Kos and Rhodes. Currently, Tilos’s electricity is supplied via an undersea cable that carries oil-based generated power from Kos to Tilos, via the island of Nisyros, but now researchers in the TILOS project are investigating an alternative approach. “We’re going to establish local scale battery storage which interacts with renewable energy sources (RES) – wind and photovoltaics (PVs) – on the supply side, together with work on demand-side management (DSM) aspects on the consumer side. We’re going to install smart meters and DSM devices into local residences on Tilos and develop a centralized energy management system (EMS) that will allow communication between the supply and the demand side, with the support of an advanced battery storage system,” says Dr Dimitrios Zafirakis, the project’s Coordinator.

The smart microgrid on Tilos will maintain communication with the main electricity system of Kos, in order to increase the security of supply and also offer guaranteed energy exports through the battery storage system. This energy scheme challenges conventional thinking. “Previously it was thought that you had to decide between having an interconnector and a storage asset. We are trying to prove that they can in fact be complementary,” says Dr Zafirakis, who stresses that “this is also in line with the fact that the electricity demand of Tilos presents considerable fluctuation over the course of a year and thus energy trade with the host grid of Kos could be really meaningful.”

Tilos has a population of around 500, which swells to between 1,000-1,500 during the summer tourist season, leading to increased energy consumption. “Overall, Tilos has an annual energy consumption of around 3 GWh and an average load demand of 250 kW, which however rises to 1 MW during the peak summer period,” outlines Dr Zafirakis.

Measuring instruments installed on Tilos island.

Below Image: Solar Radiation Station.

The battery storage system is based on FIAMM technology NaNiCl2 batteries, comprising two battery containers with a total energy capacity of 2.88MWh and nominal power of 800kW. This is projected to last for a total of 4,500 full cycles, potentially providing more than 15 years of guaranteed operation. “The system promises efficiencies in the order of 85 percent round-trip, allowing also for deep discharges. So they are quite an advanced battery storage technology,” continues Dr Zafirakis. With the energy balancing abilities of the battery system, the project is looking to maximize the local penetration of RES, in particular wind and PVs. “We’re going to install an 800 kW wind turbine on Tilos, plus PVs of 160 kW, trying also to minimise the environmental footprint of the installation, expecting to achieve annual RES penetration of more than 85 percent for the entire island,” says Dr Zafirakis. Furthermore, it is also planned that the battery system will provide guaranteed energy exports to the host grid of Kos, which suggests a valueadding energy stream for the storage asset and the community-scale smart microgrid.

Additionally, researchers plan to install 150-200 smart meters at local residences, public buildings and pumping stations on Tilos, generating more data on consumption patterns. “We will be able to monitor local consumption, and at the same time control some of these energy loads based on the residents’ consent,” says Dr Zafirakis. DSM devices will handle three different electrical loads per house, supporting the operation of the smart

microgrid through communication with the central EMS. “We’re going to control water heaters, refrigerators and air conditioning. For example, water heaters will be automatically turned off when we don’t have sufficient energy and the batteries are empty, so we won’t allow the consumer to turn it on. Then when there’s an energy surplus, the water heater will be turned on, and we can store electrical energy in the form of hot water,” explains Dr Zafirakis.

Researchers have been working closely with the local community to both train local people on the effective operation of the smart microgrid and listen to their concerns and feedback. This is essential to the effective operation of the smart grid. “If you’re not actively engaged, you’re not going to be able to run the smart microgrid effectively,” points out Dr Zafirakis.

Three different operational strategies will be investigated within the project, with researchers looking to evaluate the performance of the battery storage system and the entire smart microgrid in each scenario. “In the first, we will eliminate the energy supply from the island of Kos, and see if we can achieve 100 percent penetration of RES. This approach will be tested during winter, when energy consumption is lower,” explains Dr Zafirakis. “The second strategy involves interaction with the host electricity grid of Kos, with the undersea cable mostly used to cover energy deficits when they occur. So that’s going to be a conventional part of the operation of the system, mainly during the summer months when local consumption peaks.”

In the third strategy, the storage asset will be used to both support local energy autonomy and provide the host grid of Kos with guaranteed amounts of energy. “We’re going to consider the system as a kind of market – the microgrid will interact with the market,” continues Dr Zafirakis. “On the one hand, we want to provide energy autonomy to the people of Tilos. On the other, if surplus energy is generated, we aim to send it to the host grid of Kos under guaranteed terms.”

Researchers aim to evaluate the performance first of the battery storage system and then of the entire microgrid, assessing also the value produced in each of these scenarios. This can then provide the basis for investigating the respective market value and potential applications, especially for the battery storage system. “Is the battery just going to satisfy some local demand? Do we want to stress the battery so that it also provides guaranteed exports to the host grid of Kos? What are the implications? We’re looking at how the value of the battery varies across these three scenarios,” says Dr Zafirakis. The integrated smart meter & DSM prototype solution.

Technology innovation for the Local Scale, Optimum integration of Battery Energy Storage (TILOS)

TILOS aims to demonstrate the optimal integration of local scale energy storage in a fully-operated, smart island microgrid that will also communicate with another, main electricity grid. The main objective of the project will be the development and operation of a prototype battery storage system, based on NaNiCl2 batteries, provided with an optimum, real-environment smart grid control system and coping with the challenge of supporting multiple tasks, ranging from microgrid energy management, maximization of RES penetration and grid stability, to export of guaranteed energy amounts and provision of ancillary services to the main grid.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 646529.

Dr Dimitrios Zafirakis, Piraeus University of Applied Sciences 250, Thivon & P. Ralli St., Egaleo, 12244 Greece T: +30-2105381580 E: dzaf@teipir.gr W: http://www.tiloshorizon.eu/

Dr Dimitrios Zafirakis

Dr Dimitrios Zafirakis is an Energy Engineer holding a Mechanical Engineering Degree from the Piraeus University of Applied Sciences - Greece, an MSc in Energy from the University of Heriot Watt - UK and a PhD in Business from the University of East Anglia - UK. His research interests include development of energy storage services’ portfolios, operational strategies for smart grids, mechanisms for achieving large-scale integration of RES and energy planning for remote areas and island regions.

On May 13, 2016, the Greek Regulatory Authority for Energy issued the production license for the first ever island-based, hybrid wind-PV-battery system in Greece and also among the first in Europe, in the context of the TILOS project. “This decision is a major breakthrough for the further development of RES-based battery storage schemes and for the gradual elimination of oil dependence for numerous island regions in Greece and elsewhere,” underlined Dr Zafirakis.

In the same vein, the TILOS researchers argue that the project’s approach could significantly reduce the cost of energy production on small island communities like Tilos. Currently, the cost of supplying energy to smaller Greek islands is far higher than on the mainland, due to the need to use imported oil for power generation; however, while the project’s research holds clear relevance in these terms, Dr Zafirakis says there are still some issues to address. “A key challenge is to dramatically reduce the costs of installing batteries,” he stresses. The priority in any case is to demonstrate the technical feasibility of the Tilos system, from which researchers can then look to develop it further. “The island is a good test case, as the costs are high, and there is a vision at the European Commission

level to promote these kinds of systems” explains Dr Zafirakis.

This knowledge will also help inform the future development and possible implementation of smart grids on other islands; the project is engaging with the islands of Pellworm, La Graciosa and Corsica. “We are thinking about energy provision on other islands, building on earlier feasibility studies,” says Dr Zafirakis.

This research is relevant not only to islands, but also mainland communities. “We are developing a smart microgrid based on RES and local-scale battery storage that can provide self-autonomy for numerous communities. At the same time, these communities can also interact with the electricity market,” outlines Dr Zafirakis.