What zero export means
Zero Feed-In — or zero export, zero export, export limitation – is the solar system that is connected to the grid, but never sends energy towards it. Production is intended solely for your own consumption and, if there is a storage system, for charging the batteries.
The grid connection is retained, but it is one-way: you draw energy when production is insufficient, but you never export. This is achieved with a mechanism power export control which monitors the flow at the connection point in real time and adjusts the inverter accordingly.
Because there is no export, there is no offsetting: no offsetting contract is signed with a supplier. The only body you deal with is the network operator, which registers the system and confirms that the zero-export mechanism works. This simplifies the administrative side of the project considerably and frees you from a multi-year contractual commitment.
Zero Feed-In is often misread as a fallback for saturated grids. In reality, for many consumption profiles – and especially for businesses operating during daylight hours – it is a a first-choice solution: faster, simpler and often with an equally good financial return.
The flow to the grid is held at zero at all times.
You are not contractually tied to a supplier for two decades.
A solution where Net Billing is not approved because of grid constraints.
Why it is used & when it is the right choice
There are four typical cases in which we recommend a zero-export system. In some of them it is the only technically feasible solution; in others it is simply the best one.
1. Saturated grid
In many parts of the country – and particularly on islands and in zones with high renewables penetration – the grid has been designated as saturated and connection terms for export are not granted. Because a zero-export system places no power flow on the grid, connection usually becomes feasible.
2. Consumption during production hours
Workshops, refrigeration facilities, offices, supermarkets, hotels and irrigation units consume mainly while the sun is high. There, self-consumption reaches very high rates and the value of exported energy would be marginal.
3. Speed of delivery
With no offsetting contract and a simpler procedure with the operator, the project can move faster. For businesses under cost pressure, that translates into savings starting sooner.
4. A desire for autonomy
Combined with sufficient storage and a hybrid inverter, a zero-export system approaches the logic of an off-grid system, while keeping the grid as a safety backup.
When it is practically compulsory
Zero export becomes the only available route when the network operator cannot grant connection terms with export for that particular location. This typically happens when saturation is caused by exceeding the rated capacity of network components or the permitted voltage limits at the nodes. There are also cases of saturation – for example due to short-circuit levels – where zero export alone is not enough to permit connection and additional technical solutions are required. We investigate this at the start of the project, so you know from day one what is feasible at your address.
How the inverter works under zero export
The inverter is the brain of the system. In a conventional grid-connected solar installation, the inverter produces whatever power the sunlight allows and feeds it into the installation – whatever is not consumed passes to the grid. In a zero-export system, the inverter works under a permanent limitation.
It continuously receives a signal from the meter at the connection point and adjusts its output many times per second, so that the power flowing towards the grid stays at zero. In practice it follows consumption: if the loads call for 12 kW, the inverter delivers up to 12 kW; if the loads drop to 3 kW, the inverter reduces production accordingly – this is called curtailment or curtailment.
In the hybrid inverters the logic is smarter. Before curtailing production, they send the surplus to the battery. The inverter only reduces power when the loads are covered and the battery is full. Energy that would have been lost is put to use, and the utilisation rate of the installation rises dramatically.
What the inverter of a Zero Feed-In system needs
- ▸Integrated function export limitation / zero export with an adjustable threshold.
- ▸Support an external smart meter or current transformers at the connection point.
- ▸Response speed fast enough to follow sudden load changes without a momentary overflow.
- ▸Grid protection and anti-islanding in accordance with the applicable standards.
- ▸Capability battery connection now or in a later phase, so the system is expandable.
- ▸Monitoring with recording of production, consumption and curtailment, so performance is documented.
How power export control works
The mechanism is a closed control loop. The diagram shows the path of the signal and of the energy.
How it works with batteries
With zero export the battery is not a luxury – it is the factor that decides whether the investment performs. Without storage, every kilowatt-hour not consumed at the moment it is produced is simply is not produced at all: the inverter curtails it.
With a battery, the midday surplus is stored and returned to the loads in the afternoon and evening. For a home this is decisive, since consumption peaks after sunset. For a business with evening shifts, refrigeration or security systems, the battery shifts production to the hours when it is actually needed.
In addition, combining a hybrid inverter with a battery unlocks backup: during a grid outage, selected critical loads continue to be supplied. See the storage options in detail on the page solar with batteries.
With and without storage
Legislation & connection requirements
Zero-export systems are explicitly provided for in the Greek self-consumption framework as a separate scheme. Their basic difference from Net Billing is institutional: the zero-export self-consumer does not sign an offsetting contract and therefore does not take on the associated multi-year commitment. The body they deal with is the network operator, which registers the system and ensures that zero export is maintained in practice.
On capacity, the framework links the size of the solar system to the agreed capacity of the consumption supply: the installed capacity in kW can reach the agreed capacity of the supply in kVA. This gives significant headroom to businesses with large supplies, but it requires careful checking of the supply details before design.
Despite the simpler procedure, zero export is not an unregulated installation. A declaration and approval to the operator are required, technical documentation of the export limitation mechanism, and Installer Declaration by a licensed engineer or electrician, certifying that the installation complies with the regulations and ELOT standards. Installations that skip these steps create safety risks and legal liability for the owner.
Note: connection requirements and operator procedures are updated over time. The description here reflects the general logic of the framework; for the exact requirements applying at the location and at the time of your project, our technical team carries out the relevant check before any commitment.
Advantages & disadvantages
Advantages
- ✓Feasible on a saturated grid – it allows connection where Net Billing is refused.
- ✓A simpler process – with no offsetting contract and the obligations that come with it.
- ✓Faster delivery – fewer externally dependent stages.
- ✓Immediate savings – every kilowatt-hour produced replaces electricity at the full purchase price.
- ✓Independence from valuation prices – the price at which export would be valued does not concern you.
- ✓A basis for autonomy – with a battery and hybrid inverter it also provides backup during outages.
Disadvantages
- —Loss of surplus without a battery: energy that is not consumed is curtailed and lost.
- —It requires more precise design: matching production and consumption becomes critical.
- —Additional equipment: a smart meter, communication cabling and often storage increase the initial cost.
- —No credit for energy that could have been exported – there is no warehouse in the grid.
- —Dependence on the reliability of the control: a fault in metering or communication puts the system into a safe but reduced mode.
- —Not always covered from the same support programmes as grid-connected schemes.
Permitting & installation process
Supply & grid check
We confirm the agreed capacity of the supply, the connection type and the state of the network in the area, in order to define the feasible system size.
Load study
Recording the hourly consumption profile and matching it against expected production, to calculate self-consumption, curtailment and the optimal battery capacity.
Technical file
Single-line diagrams, equipment datasheets and documentation of the zero-export mechanism, for submission to the operator.
Declaration & approval
Submission to the network operator to register the station and approve zero-export operation.
Installation
Mounting frames, panels, inverter, batteries, a smart meter at the connection point, communication cabling, protection devices and earthing.
Zero-export testing
Controlled load-rejection tests to confirm that export stays at zero, preparation of the Installer Declaration and handover with full technical documentation and monitoring.
Frequently asked questions about Zero Feed-In
Do I lose energy with zero export?
Without a battery, yes: production that is not consumed is curtailed. That is why we design zero-export systems either with storage, or with capacity matched to the real daily consumption profile, so curtailment is minimal.
Is Zero Feed-In worse than Net Billing?
Not inherently. For consumers with high daytime consumption the difference in the final financial result can be small, while Zero Feed-In wins on speed and simplicity. For homes with evening consumption and no battery, the Net Billing is usually preferable.
Can I convert the system to Net Billing later?
Technically it is feasible, provided the equipment was selected with that prospect in mind and provided grid margin is released in future. That is why we choose inverters and topologies that do not lock you into a single path.
What happens if the control meter fails?
Correctly configured inverters move to a safe state: they sharply reduce or stop production so that no unintended export occurs. Our monitoring alerts us and we intervene.
Does it suit a home?
It suits them, but almost always with a battery – otherwise most of the midday production would be curtailed. For homes we recommend a hybrid inverter with storage and backup functionality.
Want to see whether the grid in your area allows export?
Send us the address and the details of your supply. We will check what is feasible and propose the solution with the best return – Net Billing or zero export.
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