Investors, the race for the MACSE auction is on

• Launch Date: September 30, 2025
• Capacity Tendered: 10GWh BESS Storage
• Income: 15 years, up to 100% fixed toll, inflation-indexed returns
• Pacific Green: Global BESS developer with proven pedigree in construction / operation
• Investment Opportunity: Window for first tender is this summer 

It’s official: Italy’s first energy storage capacity procurement mechanism (mercato a termine degli stoccaggi or MACSE in Italian) will be launched on September 30, 2025.

The date was confirmed by Francesco Del Pizzo, president for grid development strategies and dispatching at the Italian transmission system operator Terna, during an energy transition expo staged by Italy’s main renewable energy association, ANIE Rinnovabili, in March, PV Magazine reported. 

Expectation around the exact date of the auction—one of the largest in European energy storage markets, with 10GWh of capacity on offer—had been growing following the February announcement that an original July date would be put back. 

“The first auction for the year of delivery 2028 is no longer conceivable in July,” PV Magazine said Terna’s head of system strategy, Luca Marchisio, had declared at a Renpower conference in Milan. “We will talk about September with a consultation in July.”  

MACSE represents a major opportunity for infrastructure investors not just due to the capacity on offer, which is roughly equal to all the energy storage installed in Italy to date, but also because the scheme guarantees fixed revenues indexed to inflation over 15 years.

The idea behind the programme is for project owners to effectively hand over capacity to MACSE so Terna can use it for renewable energy integration. The transmission system operator is keen to ensure the country has sufficient energy storage capacity to absorb a growing penetration of renewables on the grid. 

Remuneration under MACSE is expected to be worth up to €34,000 per megawatt contracted, depending on the discharge duration contracted. Thus, a 10-hour discharge period would earn the full €34,000, while an hour’s worth of storage would earn 5% of that amount. 

Asset owners can also operate in other markets, for instance gaining revenues from energy arbitrage, although must return 80% of profits back to Terna. It still adds up to a highly attractive package for investors seeking reliable long-term revenues. However, there are strings attached. 

The first is that this MACSE round will not be procuring energy storage in the north of Italy, so developers whose portfolios are not geographically diversified may not benefit. 

A second condition is that qualifying projects will need to have secured their AU by late August and bidders must provide significant guarantees—up to 15% of a project’s value—to be considered. 

With a requirement for bids to be registered 40 days before the cutoff point of the auction, it is important for investors to move swiftly in choosing development partners that have a good chance of success. 

Pacific Green is already primed to take part, with up to 1.6 GWh of capacity—or more than 15% of the total being procured under MACSE—potentially eligible for inclusion given timings around AU. The capacity corresponds to the second and third of five projects that Pacific Green has under development in Italy.

The first of the five 100MW projects acquired from Sphera Energy in 2023 is expected to get planning approval in April 2025 but will not be eligible for MACSE because it is located in the northern Italian region of Emilia-Romagna.

But the next two, each with potentially eight hours of storage, are within the geographical boundaries encompassed by MACSE and have been highlighted as projects of national interest by the Italian government. Two further 100MW, eight-hour battery schemes, meanwhile, should be consented in time to participate in future scheduled MACSE auctions. 

Investors participating in the projects will be assured of a tried-and-tested development strategy that has been honed across international markets. Pacific Green has a winning formula for battery plant development that has been in place since the company’s first project, the 100MW, 100MWh Richborough Energy Park in Kent, UK. 

Richborough and its sister scheme Sheaf, with 249MW and 373.5MWh, have each been developed within 28 months under a design, construct and operate model that involved raising £150 million of non-recourse project finance and delivering a total of USD$368 million of enterprise value. 

With a combined size of 475MWh, the projects represent one of the largest battery energy storage installations in Europe. Richborough was sold to the Luxembourg-based investor Generali Investment’s Sosteneo Energy Transition Fund for £74 million ($93 million) in June 2023. 

In November 2023, Sosteneo also bought Sheaf, for £210 million ($258 million). As part of the transaction, Sosteneo provided a capital expenditure loan to fully fund the development and construction of the energy park alongside a senior debt facility.

“Sheaf Energy Park represents critical infrastructure that supports the growth of renewable energy in the UK whilst benefitting from a long-term capacity agreement that provides our clients with stable cash flows,” said Umberto Tamburrino, Sosteneo’s managing partner, chief executive and chief information officer in Europe. 

More recently, Pacific Green has repeated the formula in Australia, one of the world’s most vibrant markets for energy storage. In February 2025, the company entered an agreement to sell its 250MW, 500MWh Limestone Coast North Energy Park to Intera Renewables for AUD$460 million (USD$293 million). 

The first of two energy parks being developed in Limestone Coast by Pacific Green, the project will begin commercial operations in early 2027. Simon Parbery, executive director of Intera’s owner, Palisade Investment Partners, praised Pacific Green’s approach. 

“Limestone Coast North represents Palisade’s first investment in large-scale energy storage, providing both attractive risk-adjusted returns, as well as long term strategic benefits for our Australian renewables platform,” he said.

Pacific Green is looking to replicate this model in Italy, which is the company’s second-largest market after Australia, with an initial portfolio of 3.2GWh. But to take advantage of MACSE this year, investors will need to move fast, with heads of terms agreement required by mid-August at the latest. 

Dane Wilkins, Pacific Green’s managing director for Europe, will be attending the Renmad Storage Italia event in Rome, on April 2 and 3, to discuss the MACSE opportunity with potential investment partners. If this is a market you are interested in, then get in touch now.