IN Brief:
- ARERA has backed a 16GWh storage requirement for Italy’s 2029 MACSE auction.
- The proposal follows the 10GWh already contracted for 2028 delivery in the first MACSE round.
- South and island zones remain the main focus as Italy scales storage to support renewable integration and system flexibility.
Terna is set to move ahead with the next phase of Italy’s MACSE storage build-out after ARERA gave a positive opinion on the transmission operator’s proposal for a 16GWh requirement in the 2029 auction.
The decision gives formal backing to a staged approach for the next round of long-term storage procurement. Terna’s proposal is based on an expected storage need of 42GWh by 2030. With 10GWh already procured for 2028 delivery in the first MACSE battery auction, the transmission operator identified an additional 32GWh requirement and proposed that half of that volume should be addressed through the 2029 round.
The regional split keeps the emphasis firmly on southern Italy and the islands. Under the proposal, North and Centre-North carry no requirement, while Centre-South is set at 1GWh to 3GWh, South and Calabria at 3GWh to 11.5GWh, Sicily at 1GWh to 6GWh, and Sardinia at 0.5GWh to 3GWh. ARERA also said the final auction contingents for 2029 may be reduced to reflect any storage capacity that enters service, or is procured through the capacity market, before the auction volumes are formally published.
The regulator described the approach as prudent, noting the continuing uncertainty around gas prices and the cost of new storage capacity. It also called for the requirement from 2030 onward to be updated annually, rather than fixed in one step, so future auction volumes can be aligned with changing market conditions and with Italy’s wider planning assumptions.
The move extends a mechanism that has already become a central route to utility-scale storage deployment in Italy. Terna’s 2025 results show the first MACSE round contracted 10GWh for 2028 delivery, cleared at about €13,000 per MWh-year, and drew bids at roughly four times the required volume. The full ARERA opinion is available here.
