At the Energy Transition Summit: East Med & Southeast Europe – held on 17 June 2025 in Athens and organised by FT x Kathimerini – Nikos Mantzaris, Senior Policy Analyst and co‑founder of The Green Tank, joined experts to explore how Greece and the broader region can harness the region’s rich solar and wind potential.
“We need large‑scale renewable projects to meet our climate targets — but also smaller ones for self‑production projects by prosumers,” Nikos Mantzaris asserted early in the session. He noted that prosumerism features heavily in EU legislation, especially within the “Fit for 55” package, and underscored the importance of citizen’s active participation in the clean energy transition.
In Greece, progress in self-production projects since [Russia’s] invasion of Ukraine has spurred around 900 MW of self-production projects—roughly 8–9 % of total installed PV capacity. “Small but not negligible,” he said, demonstrating real momentum.
Yet, applications have slowed: “There is a deceleration in applications for prosumer projects.” The culprit isn’t mainly the grid—it’s policy, he said, adding that “transitioning from net metering to net billing changed the economics of self-production.” His solution? “Mobilise public funds to support small battery installations.”
On market dynamics, Nikos Mantzaris debunked a common misconception: “High prices aren’t caused by renewables—gas is responsible, as it is expensive and is what sets the market-clearing price every day.” In 2024, gas accounted for about 37.5 % of Greece’s generation, the fourth highest share in the EU,—a large part of which was exported, and that is why Greece had the sixth highest wholesale electricity price in the EU, according to a recent report by the European Commission. During the same year, “We rejected significant amounts of renewable electricity because we didn’t need it at the time of generation.” His remedy: “We need to cut gas use and accelerate installation of storage infrastructure such as batteries and pump hydro to absorb excess renewable electricity at the time it is being produced and to dispatch it in the evening, thus limiting fossil gas use for electricity production.”
He also addressed another myth which we read and hear with increasing frequency, that: “we can’t rely on renewables alone, so we need many new gas plants. But Greece currently operates 6 GW of gas plants, with 5.5 GW more in development, yet never used more than 5.1 GW of combined gas and lignite in 2024.” He questioned the need for that much capacity, especially if supported by consumer-funded capacity mechanisms.
Proposing a way forward, Nikos Mantzaris urged stronger citizen engagement: “Prosumerism is vital to the energy transition and we should support it further.” He recommended dedicating 3 GW of grid capacity to consumer-led projects by 2030—about 20% of projected capacity, matching Spain’s target of 25%.
Looking ahead, he set bold targets: “We’ll be very happy if by 2030 we emit less than 4 million tonnes of CO₂ – last year we emitted four times that, largely due to the use of gas.” He noted that “cleaner electricity means cheaper electricity,” and expressed his vision “to see more than 80 % renewables in the electricity mix by 2030.”
His focus stretched beyond electricity: “Transport is becoming Greece’s most polluting sector—it needs decarbonisation too.” He also urged regional cooperation: “We should prioritise cleaner, regional energy projects rather than fossil fuels, as these will lower the costs for everyone.”
Eleni Varvitsioti (FT Greece & Cyprus Correspondent) moderated the discussion, which also featured Alexandros Flamos (Professor and Head of the Technoeconomics of Energy Systems Laboratory at the University of Piraeus), Panagiotis Ladakakos, (President of the Hellenic Wind Energy Association), and Stavros Papathanasiou, (Professor, Electric Power Division, School of Electrical and Computer Engineering at the National Technical University of Athens). Each presented their vision for achieving efficient and sustainable energy policy, to build a decarbonised, affordable, and resilient regional energy system.
Watch Nikos Mantzaris respond to the myth regarding the necessity for all new planned gas plants here.