Phase D of Cyclades’ electrical interconnection completes a sophisticated and imposing project aimed at the energy integration of the island complex in the continental system, with benefits for both the islands and the national economy in general.
The design of the project was based on the conclusions of the research regarding the alternatives for power supply in the Non-Interconnected Islands (NIIs), by a Committee consisting of competent executives of RAE, IPTO, HEDNO and DESFA.
The relevant conclusion showed that the implementation of the project is -in financial terms- the optimal solution for the reliable supply of the islands while, at the same time, ensures the minimization of environmental nuisance by situating the Substations in appropriate locations, in order to limit -as far as possible- the construction of transmission lines.
The electrical interconnection of the Southern and Western Cyclades with the HETS will be realized through submarine AC cables, with an estimated length of 353.2 km as well as underground AC cables, approximately 19.6 km long.
The call for tenders in 2020 for the interconnection of Naxos with Santorini marked the launch of Phase D of Cyclades’ electrical interconnection. This first project will cover radially the most important part of the energy demand of the islands to be interconnected while it is a crucial step for the implementation of the rest of the project, scheduled to be completed in 2024.
The main design of the electrical interconnection includes the following sub-projects:
1. Naxos-Thira: interconnection with submarine three-core A/C power cable, XLPE 150 kV, nominal capacity 200 MVA.
2. Thira-Folegandros: interconnection with submarine three-core A/C power cable, XLPE 150 kV, nominal capacity 200 MVA.
3. Folegandros-Milos: interconnection with submarine three-core A/C power cable, XLPE 150 kV, nominal capacity 200 MVA.
4. Milos-Serifos: interconnection with submarine three-core A/C power cable, XLPE 150 kV, nominal capacity 200 MVA.
5. Serifos-Lavrio: interconnection with submarine three-core A/C power cable, XLPE 150 kV, nominal capacity 200 MVA.
6. Construction of 4 new substations 150/20 kV closed GIS on the islands of Thira, Folegandros, Milos, Serifos.
The financing for the construction of the project will come from state and community funds, while the operation of the project will be financed by IPTO.
The project will further reduce the cost of Public Service Obligations (PSOs) for all consumers and will significantly cut emissions.
It creates an additional strong connecting route to the mainland interconnected System for all the Cycladic islands.
The increased transmission capacity enhances significantly the possibility of developing RES on the interconnected islands.
The project will contribute decisively to the improvement of the majority of the problems that the power generation system of the Southern and Western Cyclades is currently facing, which can be summarized as follows: a) variable energy production cost due to the use of oil in the local power plants b) high increase rate of the islands’ loads on an annual basis and c) power stability problems that can be created by the penetration of RES and in the poor degree of supply reliability, especially in cases of failures in the production system.
