Northern Aegean Interconnection — Phase B (Lesvos–Chios) is a planned segment of IPTO’s wider North‑East Aegean Islands interconnection intended to electrically integrate the islands of Lesvos and Chios with the mainland Greek transmission system. The segment is being developed as part of a multi...
IPTO and the European Investment Bank signed the loan agreement for the North East Aegean Interconnection on 17 December 2025, confirming EUR 490 million of debt financing toward the EUR 1,628 million multi-island scheme that includes the Lesvos–Chios 150 kV AC cable link. The signed EIB loan strengthens IPTO’s funding structure for implementing the interconnection and diversifies its financing sources.
On 17 December 2025, the European Investment Bank and IPTO (Independent Power Transmission Operator / ADMIE) signed the loan agreement for the North East Aegean Interconnection project, confirming EUR 490 million of debt financing toward the EUR 1,628 million multi-island interconnection scheme. The signed EIB loan covers the electrical interconnection of the islands of Lemnos, Lesvos, Chios, Samos and Skyros to the mainland Greek transmission system through Nea Santa in Thrace and Aliveri on Evia, and to the Dodecanese grid via Mastichari on Kos. The connection will primarily use 150 kV alternating current cable interconnectors and 150 kV gas-insulated substations. The EIB financing package was structured as multiple tranches with signature dates between 17 December 2025 and 26 January 2026 totalling EUR 490 million. The EIB Board had previously approved the operation on 12 December 2025. This financing agreement represents the effective financial close for the North East Aegean Interconnection programme, securing long-tenor debt alongside IPTO's own resources and the Islands Decarbonisation Fund support previously awarded. The project is intended to end the electrical isolation of the North East Aegean islands, replace local oil-fired generation with cleaner mainland electricity supply, improve security of supply, and increase capacity for integrating renewable energy sources across the island region. The Lesvos-Chios 150 kV AC cable link is one segment of this wider programme.
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Owners
North East Aegean Interconnection Phase B Lesvos–Chios, IPTO North-East Aegean Islands Interconnection Lesvos–Chios, Διασύνδεση Βορείου Αιγαίου Φάση Β: Λέσβος–Χίος, Διασύνδεση Λέσβου–Χίου 150 kV, IPTO NORTH EAST AEGEAN INTERCONNECTION (EIB-20250178)
The European Investment Bank approved EUR 490 million of loan financing for IPTO’s North East Aegean Interconnection project, which includes the 150 kV AC Lesvos–Chios submarine/underground link as part of the wider scheme connecting Lemnos, Lesvos, Chios, Samos and Skyros to the Greek mainland and Kos grids. The development bank funding supports the replacement of local oil-fired generation, integration of additional renewables and improved security of supply on the islands.
On 26 February 2025, in the final phase of IPTO’s tender for a six‑year framework agreement covering submarine cable projects for the Dodecanese and North Aegean island interconnections, participating companies submitted their binding financial and technical offers. This framework, with an initial budget of EUR 1.7 billion plus VAT, will govern cable supply and installation for multiple segments including the Lesvos–Chios link, with contract award to follow based on the most economically advantageous offer.
IPTO later confirmed that the marine surveys for both the Dodecanese and the Northeastern Aegean electrical interconnections were completed in December 2024, signalling the conclusion of the seabed investigation and routing work for the submarine cable corridors of the North‑East Aegean interconnection, including the future Phase B Lesvos–Chios 150 kV AC link.
In October 2024, Phase B of the framework-agreement tender for the submarine cable interconnections of the Dodecanese and Northeast Aegean islands commenced, involving the submission of detailed technical and economic offers by contractors pre-qualified in Phase A. This ongoing phase covers the cable scope for all relevant links, including the planned Lesvos–Chios interconnection.
By July 2024, Phase A of IPTO’s framework-agreement tender for the submarine cable interconnections of the Dodecanese and Northeast Aegean islands, which includes the Lesvos–Chios segment, was completed, with the process of receiving and assessing participation applications from interested contractors brought to a close.
In April 2024, IPTO launched Phase A of a framework-agreement tender by posting a call for expressions of interest for the submarine cable interconnections of the Dodecanese and the Northeast Aegean islands, covering cable works for segments including the future Lesvos–Chios link. This phase invited participation applications from interested contractors for the cable packages of both projects.
In November 2023, IPTO assigned contracts for studies and marine seabed surveys for the Northeast Aegean islands electrical interconnections, and by April 2024 reported that seabed surveys were already completed or in progress on several Northeast Aegean routes, marking the start of the marine geophysical survey campaign for the wider North‑East Aegean interconnection programme that includes the planned Lesvos–Chios 150 kV AC cable link.
By December 2022, additional electrical interconnections for the Dodecanese and the north‑east Aegean islands, a programme which in IPTO’s 2021‑2030 Ten‑Year Network Development Plan includes a Phase B 150 kV AC Lesvos–Chios link, were described as being "under investigation", indicating that the North‑East Aegean interconnection scheme was in an early assessment and concept‑development stage.
Independent Power Transmission Operator (IPTO) announced that its preliminary Ten‑Year Network Development Plan (TYNDP) 2021‑2030 would, for the first time, include the North Aegean Islands interconnection, with Phase B comprising the 150 kV Lesvos–Chios interconnection scheduled for completion in 2028. This plan formally embeds the Lesvos–Chios link within Greece’s national transmission development programme alongside other Dodecanese and North Aegean island links.
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