IPTO “Fortifies” the Ionian Islands: New 150 kV Links Bring Zakynthos,Kefalonia,Lefkada Into a New Energy Era

Two upgraded electricity interconnections, with a combined length of 35.2 kilometres, are replacing decades-old infrastructure and strengthening security of supply across Zakynthos, Kefalonia, Ithaca and Lefkada. IPTO is completing another major step in the systematic modernisation of the Ionian grid, while the next project is already advancing: the new Corfu–Igoumenitsa interconnection.

This is about much more than two new subsea cables.

By successfully commissioning the upgraded Zakynthos–Kefalonia and Kefalonia–Lefkada high-voltage interconnections, Greece’s Independent Power Transmission Operator, IPTO, is replacing infrastructure that had served the Ionian Islands for decades.

The immediate beneficiaries are four islands: Zakynthos, Kefalonia, Ithaca and Lefkada.

The upgrade becomes particularly important during the summer, when tourism sharply increases electricity demand and places greater pressure on island infrastructure.

35.2 Kilometres of New Energy Infrastructure

The scale of the upgrade is significant.

The new Zakynthos–Kefalonia interconnection extends for 20.4 kilometres, while the Kefalonia–Lefkada system covers another 14.8 kilometres.

Together, that means:

35.2 kilometres of new high-voltage cable systems.

Both operate with 150 kV alternating-current technology and incorporate fibre-optic telecommunications cables.

The significance is not simply the additional cable capacity. IPTO is replacing ageing links that were approaching the end of their operational life with modern infrastructure designed to improve the resilience and reliability of the islands’ electricity supply.

From Ageing Infrastructure to a Modern Grid

That distinction is crucial.

IPTO is not simply expanding an existing network.

It is progressively renewing critical infrastructure built for a different era of electricity demand.

The strategy was already visible with the Kyllini–Zakynthos link. Its upgraded 150 kV subsea interconnection entered operation in 2023, replacing an older system that had been operating for decades.

Now Zakynthos–Kefalonia and Kefalonia–Lefkada have followed.

The result is a much broader modernisation programme rather than a series of isolated cable projects.

The Bigger Project Is the Entire Ionian Energy Loop

Looking at each cable individually misses the larger picture.

IPTO is progressively reinforcing the electricity corridor running through:

Kyllini → Zakynthos → Kefalonia → Lefkada → Aktio.

That is the strategic asset.

By modernising the individual links within this loop, the Operator strengthens the resilience of the southern Ionian electricity system and reduces dependence on infrastructure installed decades ago.

For islands whose electricity needs can fluctuate sharply between winter and the peak tourism season, reliability is not a secondary issue.

It is essential infrastructure.

Energy Security Is Also Economic Security

For an island economy, electricity security extends far beyond keeping the lights on.

A resilient grid supports hotels, restaurants, businesses, hospitals, water infrastructure, telecommunications and essential public services.

During the tourism season, the challenge becomes even more pronounced as the population and economic activity of the islands expand dramatically.

That means the value of these projects cannot be measured only in kilometres of cable or kilovolts.

It is also measured in the ability of local economies to operate reliably when demand is at its highest.

Next Stop: Corfu–Igoumenitsa

IPTO’s Ionian investment programme is continuing further north.

Construction is under way on the third Corfu interconnection with mainland Greece via Igoumenitsa, covering approximately 21 kilometres.

The laying of the new 150 kV cable has already been completed.

The next stages include protection works for the subsea section, as well as the installation of the underground and overhead sections on the Corfu and Thesprotia sides.

The target is for the entire project to be completed and operational within 2027.

That will add another major layer of redundancy and resilience to the electricity infrastructure serving the Ionian Islands.

Papastavrou: “A New Era of Energy Security”

Environment and Energy Minister Stavros Papastavrou described the commissioning of the two upgraded links as the beginning of a “new era of energy security” for the Ionian Islands.

He highlighted the projects’ contribution to more reliable electricity supply, stronger infrastructure, local communities, economic activity and tourism.

Papastavrou also explicitly congratulated IPTO and everyone involved in delivering the project.

His message captured the broader significance of the investment: energy infrastructure is increasingly becoming part of Greece’s wider economic resilience strategy.

From Repairing Problems to Preventing Them

There is another important shift behind the kilometres of new cable.

A modern transmission system cannot rely on waiting for ageing infrastructure to fail before replacing it.

The more effective model is preventive:

renew critical infrastructure before it becomes the next vulnerability.

That is precisely what IPTO’s Ionian programme is designed to achieve.

The Operator has been systematically replacing interconnections approaching the end of their lifecycle, progressively transforming a network built over previous decades into infrastructure capable of meeting future demand.

IPTO Is Building for the Next Decades

The numbers tell only part of the story:

35.2 kilometres of newly upgraded interconnections. 150 kV technology. Integrated fibre optics. Four islands with stronger security of supply. An entire electricity loop being modernised. And another 21-kilometre Corfu–Igoumenitsa project advancing toward 2027.

Major transmission projects often remain invisible to the public because much of the infrastructure lies beneath the sea.

But that is precisely where one of Greece’s most important energy upgrades is taking place.

IPTO is progressively replacing the Ionian Islands’ legacy electricity infrastructure with a more modern and resilient network designed for the coming decades.

For the islands, the result is tangible:

a stronger grid, greater resilience and more reliable electricity when demand reaches its peak.

Source: pagenews.gr