Energy investment signals: grid plan, battery storage and the Greece–Cyprus interconnector (October 2026)

Snapshot#

Grid: IPTO's ten-year development plan#

The Independent Power Transmission Operator (IPTO/ADMIE) put its 2027–2036 Ten-Year Network Development Plan out for public consultation in September 2026. According to Balkan Green Energy News, the plan:

• Budget. Raises planned investment by about €2 billion compared with the previous update, to about €9 billion over the decade. Roughly 80% falls before 2030.
• Projects. Includes the Greece–Cyprus interconnector, upgrades to five large substations, and a new ultra-high-voltage centre in Alexandroupolis.
• Island links. Targets the Dodecanese and North-East Aegean island interconnections for operation by 2030.
• Cross-border links. Puts new links with Turkey and Albania at 2031. The link with Italy moves from 2031 to 2033.
• Current capacity. Reports about 9,837 MW of operational solar and wind connected to the transmission network and 8,688 MW to the distribution network. Further projects already hold connection terms.
• Storage. Reports 1,403 MW / 4,439 MWh of batteries with connection terms, of which about 500 MW were operating.

These are a grid operator's planning figures in a consultation draft. They can change before the plan is approved by the regulator, RAAEY.

Storage: the 4.7 GW standalone call#

energypress reported the following about the Ministry of Environment and Energy's call for standalone merchant batteries:

• Status. The evaluation committee had essentially completed its assessment, and a ministerial decision approving the ranking was expected in October.
• Network split. Of the 4.7 GW, 900 MW would connect to the distribution network (HEDNO) and 3.8 GW to the transmission system (IPTO).
• Demand. Applications exceeded 8 GW.
• Pipeline. Separately, RAAEY said 309 MW of previously supported storage projects were in trial operation and a further 401 MW were completed.

Operating battery capacity figures differ between sources. energypress cited about 700 MW, including converted thermal licences, while the IPTO plan coverage cited about 500 MW. Check definitions and dates before comparing.

Commissioned project: Larissa BESS#

METLEN and Karatzis Group inaugurated a 330 MW / 790 MWh standalone battery energy storage system in Larissa on 14 October 2026. The companies describe it as Greece's largest. They built it through a joint vehicle in which METLEN holds 49% and Karatzis 51%.

Interconnector: Great Sea Interconnector (Greece–Cyprus)#

• Ownership. According to Enerdata, citing a Greek government release of 5 August 2026, Meridiam acquired a majority stake in GSI, the project company set up by IPTO. IPTO remains a strategic shareholder.
• Design. The project is described as a 1,208 km, 525 kV HVDC cable with 1 GW of initial capacity, expandable to 2 GW.
• Cost and EU support. It is costed at €1.9 billion, holds EU Project of Common Interest status, and is expected to receive €657 million from the European Commission.
• Timing. Enerdata reports that completion is now expected after the original late-2029/early-2030 target.
• Surveys. As of 5 October 2026, ProtoThema reported that about 60% of seabed surveys were complete. The rest lie in waters claimed by both Greece and Turkey, and the timing of further surveys remained unresolved.

Cost context#

Energy-linked inputs are feeding through to other sectors. ELSTAT's construction material index showed diesel up 23.2% year-on-year in August 2026 (construction costs note). Electricity supply drove much of August's industrial production rise (industry note).

Sources#

• IPTO: draft Ten-Year Network Development Plan 2027–2036 (PDF, Greek)
• Balkan Green Energy News: IPTO plan coverage (14 Sep 2026)
• energypress: 4.7 GW battery call
• METLEN: Larissa BESS press release
• Enerdata: Meridiam majority stake in GSI (7 Aug 2026)
• ProtoThema: GSI survey status (5 Oct 2026)
• RAAEY (energy regulator)