METLEN and Karatzis Built Greece's Largest Battery for EUR 170m in Six Months. Only EUR 33m of It Was Sponsor Money

Most of the write-ups filed this as a renewables milestone. I read it as a financing template with an expiry date. Alpha Bank's figures of 15 October 2026 put the build at EUR 170m. Of that, EUR 81m came from the Recovery and Resilience Facility. Sponsor money was EUR 33m.

Prime Minister Kyriakos Mitsotakis opened the plant at Nees Karyes in the Larissa region on 15 October 2026. It is rated 330 MW with 790 MWh of storage. Balkan Green Energy News reported that it was completed in six months with more than 880 people involved. The owner is KARMET Energeiaki, a joint venture. Karatzis Group holds 51 per cent and METLEN 49 per cent. METLEN built the plant and keeps the operation and maintenance.

The capital stack is the real news here

Alpha Bank acted as exclusive arranger and lender for EUR 56m. The Recovery and Resilience Facility, through the Greece 2.0 plan, carried EUR 81m. The project's investors covered the remaining EUR 33m. Public money therefore funded 48 per cent of a merchant asset. Sponsor cash funded 19 per cent. One commercial bank took 33 per cent, and it took that position behind a public loan.

Few European flexibility assets have been built on so thin an equity ticket. At EUR 170m across 330 MW the build cost is about EUR 515,000 per MW. Across 790 MWh it is about EUR 215 per kWh. The duration is about 2.4 hours. Those three numbers are arithmetic on the reported figures rather than disclosed metrics.

Six months was a funding decision before it was an engineering one

The programme reads as an engineering result, and it is one. It is also a funding-window capability. The Recovery and Resilience Facility required all milestones and targets to be met by 31 August 2026. Member States had to file final payment requests by 30 September 2026. The Commission must complete payments by 31 December 2026.

An asset with a three-year build could not reach that money at all. One with a six-month build could. About 55 MW a month went in at Nees Karyes. A contractor who can mobilise 880 people for a half-year burst is selling more than civils and cabling. It is selling access to a closing funding window.

Merchant revenue sitting behind a public loan

The revenue side carries no price guarantee. The Thessaly plant has no contract for difference and no operational support agreement. It earns from arbitrage, balancing and ancillary services in the Greek market. The smaller Faria Renewables unit at Galanovrysi opened in the same week on a different basis. That one is 49.9 MW and 134 MWh and sits on support from Greece's second storage auction.

So the state took credit risk here, at a low rate and over a long tenor. It left the price risk with the sponsors. That is a cheaper way for a government to buy flexibility. It is also harder to repeat once the fund is shut. The next sponsor in this market meets a lender asking for a larger equity cheque. The revenue stack behind it has not changed.

The cost curve moved in batteries' favour, then paused

Wood Mackenzie published its global levelised cost work on 8 October 2026. Four-hour storage now beats open-cycle gas turbines on cost in all 43 markets where both were modelled. The same work found battery turnkey capex rose about 2 per cent in 2026. That is the first annual rise in three years, driven by cell prices and lithium. Wood Mackenzie expects a 12 per cent fall by 2031. Europe carries the highest fossil generation costs of any region it models.

Read those findings together before signing anything. The economic case for storage against peaking gas is settled for now. The equipment price underneath that case stopped falling in the same year the subsidy window shut.

The read-across for CEE arrives immediately

Mr Mitsotakis said Greece wants 3 to 4 GW of storage operating or under implementation by 2028. He also said about EUR 200m of public money is still going into comparable work. Greek operating battery power is now close to 1 GW after this plant and the Faria unit.

The same sponsors are already exporting the model. METLEN and PPC formed a joint venture in March 2026 for battery projects. The target is up to 1.5 GW and 3 GWh in Romania, Bulgaria and Italy. None of those markets has a Recovery and Resilience loan window left to draw on. Each will have to price the same asset on bank debt, sponsor equity and whatever national scheme exists.

For contractors the lesson is about programme shape. Flexibility work now arrives in short, labour-heavy bursts tied to a funder's calendar. The firms built for that shape will take the margin. For sponsors and lenders the live question is the equity line. A merchant battery funded on 19 per cent sponsor cash is one asset. The same battery at 35 per cent in 2028 is another. For public sponsors the Greek case is worth copying while the detail is fresh. A cheap public loan behind a merchant revenue stack delivered 330 MW in six months. It promised nobody a price.