On-site exchange
On-site exchange has been one of the main tools supporting the spread of photovoltaic systems in Italy for years. It is a form of on-site self-consumption that allows electricity generated and fed into the grid at a certain time to be offset against electricity drawn at a later time. In other words, the electricity grid functions as a sort of “virtual storage,” allowing energy not immediately consumed to be used later.
With this mechanism, the energy produced by a domestic system, such as a photovoltaic system, could be fed into the grid and generate a “credit” to be used when production was insufficient to cover consumption.
However, following decisions by ARERA and GSE, Net Metering is set to disappear: starting May 29, 2025, it will no longer be possible to join the service with new systems. For those already active, the agreement can last a maximum of 15 years, after which the service will automatically cease and the excess energy fed into the system will be recovered through the Dedicated Withdrawal (RID) mechanism.
How does the on-site exchange work?
- Requirements: The generation plant and the point of consumption must be connected to the same connection point with the public grid.
- Grid feed-in: Excess energy produced and not self-consumed is fed into the electricity grid.
- Grid withdrawal: When consumption exceeds production, energy can be drawn from the grid.
- Virtual storage: The grid acts as a “virtual battery,” eliminating the need for physical storage systems.
- Offsetting: Energy withdrawn is offset against energy fed into the grid, generating a financial credit for the plant owner.
Access to the mechanism: conditions and deadlines
- Deadline for new applications: Applications can be submitted until September 26, 2025, exclusively for systems that entered into service by May 29, 2025.
- No new systems: Starting May 30, 2025, it will no longer be possible to activate SSP agreements, pursuant to ARERA Resolution 78/2025.
- Activation: For systems under 200 kW, registration is done using the updated version of the Single Form.
- Contract duration: The agreement has a calendar year term, tacitly renewable, but no longer than 15 years from the first signing (Legislative Decree 181/23 and ARERA Resolution 457/2024/R/efr).
What changes from 2025
- Ban on new installations: Starting May 29, 2025, access to Net Metering is no longer possible.
- End of service for existing installations: existing agreements remain valid only until the natural expiration of the 15-year period.
- Switch to Dedicated Withdrawal (RID): Once the maximum agreement period expires, installations will automatically enter the RID mechanism. In this case, the energy fed into the grid will no longer be compensated but sold to the GSE, which will remunerate it. Energy withdrawn from the grid, however, will be paid to the supplier as usual.
Conclusion
On-site exchange has been an effective tool for leveraging renewable energy generated and not self-consumed, offering producers the opportunity to use the grid as a “virtual battery.” It has provided direct economic benefits and incentivized more sustainable energy practices. Under the new rules, the scheme will remain accessible only to plants commissioned by May 29, 2025, with applications open until September 26, 2025. Those wishing to benefit from it must therefore respect these deadlines and, at the same time, carefully evaluate the future prospects associated with the transition to systems such as Dedicated Withdrawal and Renewable Energy Communities.