Greek Independent Power Transmission Operator (IPTO or ADMIE) submitted its ten-year development plan for public consultation. The company aims to connect more than 10 GW of renewables capacity by the mid-2030s.
The new plan, covering the period of 2027-2036, increases investments by EUR 2 billion from last year’s update. IPTO now expects to invest EUR 9 billion within a decade, with about 80% earmarked until 2030.
Its main goals are to complete the next wave of island interconnections and international ones, prepare the system for a higher share of renewables and ensure stable operation across all scenarios.
New projects in the ten-year plan include the Great Sea Interconnector between Greece and Cyprus, upgrades to five large substations, and a new ultra-high voltage center in Alexandroupolis.
Demand to rise slower than in NECP projection
When it comes to future electricity demand, the operator expects a lower volume than in the National Energy and Climate Plan (NECP). Instead of a rise from 51 GW in 2025 to 74 GW in 2036, IPTO is projecting the total demand to reach 64 GW.
The main drivers will be large industrial consumers, data centers, and the wider electrification of the national economy. Peak demand is set to rise from 11.5 GW to 15.1 GW during this period.
Mature renewables investments able to deliver 2035 goal
There are currently some 9,837 MW of operational solar and wind farms in the transmission network, together with 8,688 MW in the distribution network. In addition, projects for 13,228 MW and 794 MW overall, respectively, have received connection terms, leading to a total of 32.547 MW of either installed or fully mature.
IPTO noted that the NECP projected 18.5 GW of installed solar and 9.5 GW of wind by the year 2035, together with 3.9 GW of offshore wind farms.
The total projected rise in installations across both technologies amounts to 10 GW compared to 2025. Therefore, the 14 GW of projects with connection terms are considered enough to fully cover this future capacity.
In fact, the actual pace of installations has been faster than NECP estimations. This is especially evident in photovoltaics, which already reached the 2030 goal of 13.5 GW this summer. Therefore, the actual trajectory up to 2036 may differ significantly compared to NECP scenarios.
As for energy storage, 1,403 MW / 4,439 MWh of battery units have received connection terms, while about 500 MW are already operating. The government recently updated its goal for 2030 to between 5 GW and 7 GW, against 4.3 GW previously.
Investments in reactive power are a must have
Another area where IPTO focuses on is reactive power. Recent events such as the big blackout in Spain last year showed the importance of having adequate means to manage a system with high renewables penetration.
The operator aims to upgrade its substations with special equipment and strengthen the overall network. Specifically, inductance would be included in 150 kV substations to cover 5,213 MVA by 2035, up from 2,286 MVA in 2025.
New interconnections enter mature stage
IPTO is called to build various new interconnections in the next few years. The most important ones are new lines connecting islands in the Dodecanese and Northeast Aegean to the mainland. These investments are expected to become operational by 2030.
Greece also aims to build new connections to neighboring countries, or updgrade existing ones. New lines with Turkey and Albania are set to conclude by 2031, while the one with Italy has been pushed back from 2031 to 2033.
