What Is Zero Export? Zero Feed-In Solar

Key Takeaways

Zero export means solar output is used only for self-consumption, with none fed to the grid.
A controller measures power at the connection point and curtails the inverter in real time.
Needed due to connection permits, grid capacity or economics.
Curtailed energy is lost; response latency can cause brief export violations.
Curtailment loss and export violations are invisible without monitoring.

Not every solar plant can send its surplus energy to the grid. In some facilities, generation is limited to on-site consumption only; zero energy is fed to the grid. This is called zero export (zero feed-in). This article explains what zero export is, why it is needed and how it works.

What Is Zero Export? Zero export (zero feed-in) means a solar plant uses the energy it generates only for the facility's own consumption and sends none to the grid. The inverter and controller limit instantaneous generation to instantaneous consumption; any surplus above consumption is automatically curtailed. This keeps the power flowing from the connection point to the grid at near zero.

Why Is Zero Export Needed? Several common reasons: - Connection permit: Some solar connections are granted for "self-consumption only," with no sale (net metering) to the grid. - Grid capacity: The distribution company may not allow feed-in due to transformer or line capacity. - Economics: Where net metering is unavailable or unattractive, to avoid giving surplus generation to the grid for free. - Faster commissioning: The connection process is often simpler when no energy is fed to the grid.

How Does Zero Export Work? A current transformer (CT) and power meter is placed at the connection point (meter or transformer inlet). The controller continuously measures the power flowing to the grid; as it approaches zero, it curtails inverter output in real time. Response time is critical here: a slow system briefly feeds back during sudden consumption drops, which can trigger a warning or penalty. A good system reacts within milliseconds.

Challenges of Zero Export - Curtailment loss: Because generation is capped at consumption, you cannot get the plant's full theoretical yield; curtailed energy is lost. - Latency risk: Measurement and communication delay can cause a brief export violation. - Multi-inverter coordination: With several inverters, curtailment must be distributed correctly among them. - Visibility: Without seeing how much generation is curtailed and whether an export violation occurred, you cannot be sure the system works correctly.

Zero Export Monitoring with SolarTools SolarTools monitors the power flow at the connection point, inverter curtailment and possible zero-export violations in real time. It shows how much generation is curtailed (curtailment loss), whether the rule is being violated and whether the inverters respond correctly. So you maintain grid compliance while managing curtailment loss to get the highest possible yield from your plant. Try it free for 14 days.

Frequently Asked Questions

What does zero export mean?

It means a solar plant uses its energy only for the facility's own consumption and feeds none to the grid. The inverter automatically curtails surplus above consumption, keeping export power at the connection point near zero.

Why is zero export used?

Some connection permits are self-consumption only (no grid sale); the distribution company may disallow feed-in due to transformer/line capacity; or it is chosen to avoid giving surplus to the grid for free where net metering is unattractive.

Does zero export reduce solar yield?

Yes — because generation is capped at self-consumption, curtailed energy is lost. To minimize the loss you raise consumption (load shifting) or add storage; the amount curtailed is only visible through monitoring.