If you have a photovoltaic system or are thinking of installing one, you've probably heard of net metering (Scambio sul Posto). It's one of the most discussed mechanisms in the world of solar energy in Italy, yet it often remains misunderstood: those who know it well understand that it represents an opportunity, but also a system with structural limitations that are important to comprehend before investing.
In this guide, we explain how net metering works, the requirements to access it, its advantages and disadvantages, and, above all, why the evolution towards photovoltaic storage systems is redefining the relationship between domestic producers and the electricity grid.
What is net metering?
Net metering (SSP) is an incentive mechanism introduced in Italy and regulated by the GSE (Gestore dei Servizi Energetici). Essentially, it allows those who own a photovoltaic system to feed unused electricity into the grid and draw it back later, instead of selling it at market price or wasting it.
The difference compared to a simple sale is crucial: with net metering, the energy you return to the grid is not paid to you in euros, but is credited to you in the form of energy, which you can draw when you need it — in the evening, at night, or in the winter months when the photovoltaic system produces less.
Everything is managed through a standard contract with the GSE, and the net metering contribution is calculated annually based on the energy actually exchanged.
How net metering works in detail
The mechanism is simpler than it seems. Imagine your home as a closed system connected to the electricity grid:
During the day, when the sun shines:
Your photovoltaic system produces energy. A portion of it you consume immediately at home (appliances, lights, electric vehicle charging). The excess, instead of remaining unused, is fed into the electricity grid.
In the evening, at night, or when the photovoltaic system doesn't produce enough:
Your home still needs energy. Instead of purchasing everything from the grid, you draw the energy you previously fed in. The balance between energy fed in and energy drawn is calculated by the GSE on an annual basis.
The net metering contribution:
This is not a cash refund, but an economic value attributed to the exchanged energy. This value serves to offset the transport and distribution costs that the system owner would otherwise avoid. In practice, the GSE grants you a credit that reduces the amount you would have had to pay to the grid.
Requirements to access net metering
Not everyone can access the mechanism. The main requirements are:
Photovoltaic system with power not exceeding 200 kW
Net metering is reserved for systems with a nominal power of up to 200 kW, provided they are connected to a withdrawal point with a voltage different from high voltage (i.e., most domestic and commercial users).
Energy end-use
The system must be intended to meet the energy needs of a property located in the immediate vicinity. It is not possible, for example, to power a home with a system installed on a roof kilometers away.
Bidirectional meter
A meter is required that can record both the energy drawn from the grid and the energy fed into the grid. Today, almost all modern meters installed by distributors are already bidirectional, but if not, their replacement must be requested.
Contract with the GSE
The system owner must sign a net metering agreement with the GSE, which provides for periodic communication of production and consumption data.
Advantages of net metering
Ease of management. Once the agreement is activated, the mechanism works automatically without the owner having to do anything. There is no need to sell energy to third parties, sign additional supply contracts, or manually monitor flows.
Reduced bill. The main economic advantage is that the energy produced and then consumed at a different time from production is not paid at the full price of the energy tariff, but is compensated through the net metering contribution. This can translate into significant savings, especially for those with consumption spread throughout the day.
Accessible to all. You don't need to be an energy expert or have advanced technical skills. The mechanism is designed to work transparently and automatically.
Limitations and disadvantages to be aware of
Despite the advantages, net metering has some critical issues that are important to know before basing your entire savings plan on this mechanism.
The value of exchanged energy is not equal to the value of consumed energy. The net metering contribution is calculated by the GSE based on formulas that take into account parameters such as the PUN (National Single Price) and network costs. It is therefore not a 1:1 exchange: feeding in 1 kWh and drawing out 1 kWh does not mean zeroing the bill. In some market conditions, the contribution may be lower than the real value of the energy.
The calculation is annual. Net metering is balanced on an annual basis. This means that if you produce a lot in one month and consume little, the excess contributes to the positive balance, but is not necessarily remunerated optimally. Those with consumption concentrated in summer (air conditioning, swimming pools, appliances) may benefit more than those with prevailing winter consumption.
It's not a cash payment. With net metering, you don't receive a bank transfer from the GSE, but a credit that reduces the amount to be paid. If your system produces much more than you consume, you may find yourself with a residual credit that cannot be fully utilized.
Network tariffs remain your responsibility. Transport, distribution, system charges, and taxes still represent a significant portion of the bill, and are not eliminated by net metering. Fixed fees and general system charges are paid regardless of how much energy is produced.
Photovoltaic net metering: the role of storage
Here's the game-changer. If your system produces much more energy than you consume, that excess, even if exchanged, doesn't generate a real economic advantage for you if it's not actually consumed.
This is where the storage system comes in: instead of relying solely on the net metering mechanism to "recover" excess energy, with a storage battery you can store it directly and consume it whenever you want, drastically reducing your dependence on the grid.
The concrete advantages:
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Real self-consumption instead of theoretical: without storage, energy you don't consume immediately is exchanged with the grid at a lower value than the same energy would have if consumed at home. With storage, you use it when you actually need it.
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Reduced exposure to market prices: by storing solar energy and using it in the evening hours, you avoid buying electricity from the grid precisely when prices are highest.
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Backup in case of blackout: a storage battery keeps the house powered even when the grid goes down, which net metering cannot do.
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Greater flexibility for EV charging: with an electric vehicle, you can schedule charging during hours when you have stored solar energy, zeroing out your "fuel" cost.
In summary: net metering works, but it works better — and saves you more — when combined with a storage system that maximizes effective self-consumption.
GONEO: photovoltaic storage for those who want to maximize their system
Among the storage solutions designed to complement a photovoltaic system under net metering, GONEO systems offer an approach that combines ease of installation, intelligent management, and structural safety.
GONEO is a company with over 30 years of experience in the electrical solutions sector. The GONEO residential storage line includes All-in-One systems that integrate a photovoltaic inverter, a storage battery, and, in some versions, an electric vehicle charger — all in a single unit with plug-and-play architecture and pre-configured connectors.
Attention to safety is a particularly relevant aspect in this context: European certifications (IEC 62109, VDE-AR-N4105, EN 50549, and others) guarantee compliance with the requirements for both installation and connection to the grid under net metering.
Net metering and storage: what to choose
There is no single answer. The choice depends on several factors:
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Household consumption: if most of your consumption occurs during the daytime hours (you are often home during the day), net metering alone might already offer you a good advantage. If, however, you consume mainly in the evening, storage becomes much more attractive.
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System size: a large system produces a lot of surplus and benefits from a battery to store the excess instead of feeding it into the grid.
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Energy tariff: if you pay a single-rate tariff or have high PUN bands, storage better protects you from price volatility.
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Financial plan: storage has an additional initial cost. It must be evaluated whether the incremental savings justify the investment compared to net metering alone.
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Electric vehicle: those who own or intend to purchase an EV have an additional factor that pushes towards storage, given that charging can be optimized based on available solar energy.
In general, for a new generation photovoltaic system, the combination of net metering and storage represents today the most complete approach: it benefits from the state incentive while maximizing effective self-consumption.
In summary
Net metering is a useful and accessible mechanism that allows owners of photovoltaic systems not to waste excess energy produced, by feeding it into the grid and retrieving it when needed. It is a real advantage, but it is not a complete solution: alone, it does not zero out the bill and does not protect against price peaks during hours when no energy is produced.
Adding a photovoltaic storage system transforms the model: instead of relying on the GSE to compensate for exchanged energy on an annual basis, you store it directly at home, use it when you want, and reduce your bill more immediately and predictably.
For those who want the best of both worlds — the incentive of net metering and the independence of storage — choosing a certified, safe, and easy-to-install system like those in the GONEO range represents a concrete step forward.
The sun is free. But without storage, a significant part of what it produces ends up not being yours.
