What is it, how does it work and what happens from September?
If you have installed a photovoltaic system or are about to do so, the Scambio Sul Posto, also known as SSP, has been for years among the most interesting tools to enhance the photovoltaic energy produced and not consumed.
Something, however, is about to change: from 26 September 2025, access to new SSP agreements will be closed, as required by recent regulatory provisions. Let’s see together how the SSP works, what will change in the coming months and how to manage the closure of the SSP mechanism.
What is the Scambio Sul Posto (SSP) and how does it work?
Scambio Sul Posto (on-site exchange), also known by the acronym SSP, is a mechanism managed by GSE (Gestore dei Servizi Energetici / Energy Services Manager), which allows owners of a photovoltaic system (but also cogeneration, wind, hydroelectric or small-scale biomass systems) to financially compensate for the energy fed into the grid with that withdrawn when their system is not producing.
Let’s simplify the concept even further: if during the day your photovoltaic system produces more energy than you consume, the excess electricity is fed into the national grid. At a later time, when you need more energy (for example in the evening), you draw it from the grid.
In other words, we can argue that plants with SSP use the national electrical system as a virtual storage of energy that is not immediately used. In fact, it is essential to underline that the excess energy produced is not physically stored in a real storage battery managed by the electrical system, but on the contrary is immediately fed into the grid and made available to other users.
Thanks to a compensation mechanism (usually annual), a virtual balance is generated between the energy you have “deposited” (introduced) and the energy you have “withdrawn” from the grid. This balance is then used to calculate an economic contribution, called contributo in conto scambio (contribution in exchange account), which takes into account both the energy injected and the energy withdrawn:
- If the energy fed in is greater than that withdrawn, the GSE proceeds to a refund for the excess energy.
- If the energy withdrawn is greater than that fed in, only the difference is consequently charged.
End of Scambio Sul Posto: what will change from September 2025?
As specified above, it is possible to submit a new request for access to the SSP mechanism until next September 26, 2025 only for plants that entered into operation by May 29, 2025.
Existing plants that benefit from this regime will continue to enjoy the benefits until the natural expiration of their contract. After 15 years of seniority of the contract, the GSE will proceed with the automatic closure of the same on 31 December 2024, and the consequent liquidation of the accrued surpluses. If the owner of the plant does not request an alternative from Terna within the established terms, the GSE will activate the Ritiro Dedicato.
For new users, however, after May 29, 2025 it will be essential to analyze specific cases and define what new forms of incentives could be designed to maximize the benefit deriving from the installation of a new photovoltaic system. As an example:
- a design aimed at maximizing self-consumption, for example by installing a storage system to reduce the amount of energy to be fed into the grid;
- signing a RID contract with the GSE, which pays the producer a certain price for each kWh fed into the grid, the amount of which depends on the type of system and any additional incentives the system benefits from;
- oining, where possible, a CER (Renewable Energy Community), sharing the energy produced within the community and taking advantage of the incentives provided by the specific decree.
The future of your photovoltaic system starts now! Whether you already have a system or are considering installing it, don’t be unprepared for the end of Scambio sul Posto. Contact Southenergy today for a free consultation. Our dedicated team will show you the most advantageous solutions and assist you in managing incentives, also providing you with clear and personalized guidance on the best energy strategies.
We can take care of every technical and bureaucratic detail (Due Diligence and Asset Management), essential services aimed at defining our projects as truly “turnkey”. In fact, there are many customers who have long relied on our company and who today can enjoy important economic benefits deriving from the valorization of the energy generated by their photovoltaic systems.
How to access to Scambio Sul Posto
To access the SSP, it is necessary to stipulate an agreement with the GSE (Gestore dei Servizi Energetici). Be careful, however it is possible to submit a new request for access to the Scambio sul Posto (SSP) mechanism until 26 September 2025 only for plants that entered into operation by 29 May 2025.
This was established by the recent Deliberazione ARERA 78/2025/R/efr in implementation of the provisions of art. 9, paragraph 2 of Legislative Decree 199/21.
In order to activate the SSP for photovoltaic, the system must be connected to the grid and equipped with a bidirectional meter, which records both the energy fed in and the energy withdrawn. Furthermore, the energy produced must be used at least in part for the consumption of the site on which the system is installed: this is the principle of self-consumption.
In short, the SSP is designed for those who install a photovoltaic system to reduce their energy consumption and, at the same time, benefit economically from the excess energy produced by feeding it into the grid.
The activation process is completely digital and takes place through the GSE portal, where you can create a user profile and upload all the necessary documents. Despite the simplification of the procedure, we suggest relying on qualified operators who can manage the registration but also the verification of the data reporting with extreme attention, maximizing the final economic benefit for the customer.
The technical data of the system will be essential during registration, together with the POD code of the meter, the bank details (to receive GSE refunds) and the documentation certifying the system’s compliance with current regulations.
Once the request has been sent, the GSE evaluates the documentation and, where consistent with the regulations and the resulting technical data, proceeds to stipulate the agreement. From that moment the user begins to benefit from the SSP mechanism, receiving an economic contribution for the energy fed into the grid and valued according to the contractual conditions.
Calculation of the GSE Scambio Sul Posto
The economic contribution recognized by GSE for SSP is based on a specific formula, which takes into account both the energy fed into the grid and the energy withdrawn. The calculation of the contribution is expressed as follows: Cs = min (Oe ; Cei) + CUsf x Es
Where (*):
- Cs = contribution in exchange account, i.e. the final value of the contribution that the GSE recognizes to the user;
- min (Oe ; Cei): this part of the formula indicates that the lowest value between the cost of the energy withdrawn (Oe) and the equivalent value of the energy fed in (Cei) is taken;
- Oe = Charge for energy withdrawn from the grid, i.e. the cost in € that you would have incurred for all the energy you withdrawn. Oe = Prezzo Unico Nazionale x kWh withdrawn;
- Cei = Value of energy fed into the grid, or the economic value in € of the energy you fed into the grid. Cei = Energy hourly zonal price x kWh withdrawn;
- CUsf = Flat rate exchange unit fee, a value established by ARERA and expressed in € cents which quantifies some network costs and general system charges normally paid in the bill;
- Es = amount of energy exchanged, or the minimum value between inputs and withdrawals.
(*) Definitions expressed in simplified form as a general example, for an accurate consultation please refer in full to the GSE “Regole Tecniche – Servizio di Scambio sul Posto”.
The calculation mechanism takes into account all these factors, ensuring a fair balance between the benefit for the producer-consumer and the sustainability of the electrical system. In other words, the greater the balance between production and consumption, the greater the economic advantage generated by the photovoltaic SSP.
Who can access to Scambio Sul Posto
End customers who are simultaneously producers of electricity through a system connected to the grid at the withdrawal point (user) for which they request the SSP can access the GSE photovoltaic SSP mechanism:
- Customers present within an Altro Sistema Semplice di Produzione e Consumo (ASSPC – Other Simple Production and Consumption System) who, at the same time, are producers of electricity in relation to the production plants that constitute the ASSPC, or have received a mandate without representation from a third-party producer in relation to the aforementioned plants (Scambio sul Posto for ASSPC);
- Customers who own a set of withdrawal and injection points, even if not coinciding, who, at the same time, are producers of electricity in relation to the production plants connected via the aforementioned points, or have received a mandate without representation from a third-party producer in relation to the aforementioned plants (Scambio sul Posto altrove / Exchange on Site elsewhere).
The SSP mechanism must always be verified in order to avoid incompatibility with other incentive mechanisms that provide for the direct sale of the energy produced.
Furthermore, the exchange user must be a counterparty to the purchase contract referring to the electricity withdrawn at the exchange point. Finally, in order to access the SSP service, some constraints relating to the installed power must also be respected, as detailed in the aforementioned SSP GSE Technical Rules.
FAQ Scambio sul posto
What SSP is?
The Scambio Sul Posto is a mechanism managed by the GSE (Energy Services Manager) that allows producers of electricity from renewable sources (such as photovoltaic) to feed non-self-consumed energy into the grid and receive a financial contribution based on the energy subsequently withdrawn from the grid.
Who can access to the Scambio sul Posto?
Owners of systems powered by renewable sources (including photovoltaic), both private individuals and companies, can access the SSP, provided that the energy is produced and self-consumed at least in part.
How does the financial reimbursement work?
Simplifying the formula, GSE calculates a contribution in exchange account (Cs) based on the energy fed in and withdrawn. The contribution is not a simple purchase of energy but an economic compensation between the energy given and that purchased from the network.
How do I request the Scambio sul Posto?
The request must be forwarded directly to GSE through its online portal. The user must register, enter the system data and sign the contract. It is advisable to be assisted by a qualified operator to avoid errors in the procedure.
What is the difference between Ritiro Dedicato and Scambio Sul Posto?
In both cases we are talking about commercial regimes managed by GSE. While Ritiro Dedicato is a mechanism for direct sales of energy produced and fed into the grid to GSE, Scambio Sul Posto is a compensation mechanism between energy sold to the grid and energy consumed.