SolarEdge Export Limit — G99 Configuration & Curtailment Fix
Your SolarEdge system is curtailing generation because of its export limit configuration. If the monitoring graph shows a flat line during peak sun — even when you have loads running — the export meter or CT clamp is likely misconfigured or has lost communication with the inverter.
If your system flat-lines during peak sun even when household loads are running, the export meter communication has probably dropped — forcing the inverter into fixed limiting. We restore dynamic limiting remotely via SetApp.
Book Configuration Review — from £75 → Back to SolarEdge hubIndependent — not affiliated with SolarEdge Technologies.
Most UK SolarEdge systems above 3.68 kW have a G99 export limit configured via SetApp. The limit should only restrict grid export — not total generation.
6-step export limit diagnosis
If your SolarEdge system is generating less than it should during peak sun, the export limit configuration is the first thing to check.
Understand what export limiting does and why your system has it
Export limiting controls how much power the inverter sends to the grid. In the UK, systems above 3.68 kW single-phase require G99 approval from the DNO, and most G99 approvals include an export limit — typically 3.68 kW or zero export.
The inverter monitors grid export in real-time using a revenue grade meter or CT clamp at the grid connection point, and automatically reduces output when export approaches the limit. The limit should only affect power sent to the grid — not total generation. Your system should still produce enough to cover household consumption plus the export limit.
Check whether your system is curtailing more than it should
The clearest sign of an export limit problem is a flat line on your generation graph during peak sun. Open the SolarEdge monitoring portal and compare your daily generation curve against what the panels should produce. A healthy system follows a smooth bell curve peaking around midday.
If the curve flattens at a consistent level — even when you are running dishwashers, washing machines, or other loads — the export limit is probably misconfigured. With a 3.68 kW export limit and 2 kW household consumption, the inverter should produce up to 5.68 kW before curtailing. If it is flat at 3.68 kW total, the system is ignoring your self-consumption and applying a fixed cap.
Identify whether you have dynamic or fixed export limiting
Dynamic limiting uses the meter to track real-time export — the inverter adjusts continuously to keep export below the limit while maximising self-consumption. This is the correct mode for most UK installations.
Fixed limiting applies a hard cap on total output regardless of what you are consuming. If your system curtails even with high household loads, it may be set to fixed mode — or the meter communication has failed.
When the inverter loses contact with the export meter, it falls back to fixed limiting as a safety measure. This is the single most common cause of unnecessary over-curtailment on SolarEdge systems in the UK.
Check the CT clamp orientation and meter communication
The CT clamp at the consumer unit must have its arrow pointing toward the grid — not toward the inverter. If the orientation is reversed, the meter reads export as import and vice versa. This causes the inverter to produce more when it should curtail and curtail when it should produce.
Check the RS485 cable between the meter and the inverter communication board — a loose connection causes intermittent communication loss, triggering the fixed-limit fallback. In SetApp or the monitoring portal, the meter status should show as connected with live readings.
Error 3x6E in the event log means the meter is not being detected. Check the meter ID matches the inverter configuration, verify the RS485 connections at both ends, and confirm the meter has power (status LEDs should be lit).
Export limit changes require installer-level access
SolarEdge locks export limit configuration behind installer-level authentication in SetApp. Homeowners can view monitoring data but cannot access the export limit, meter configuration, or grid compliance settings. This is a safety measure — incorrect settings can violate your G99 agreement.
If the export limit needs adjusting, it must be done by a qualified installer with SetApp access. If your original installer is no longer available or has gone out of business, STS can reconfigure the system remotely.
Book a configuration review if you are losing generation
If your monitoring shows consistent curtailment during peak hours while household loads are running, the system is leaving energy on the table. STS reviews your monitoring data to quantify the loss, checks the export limit configuration remotely via SetApp, and corrects the settings.
Common fixes: restoring dynamic limiting after a meter communication failure, correcting CT clamp polarity, updating the export limit value to match your DNO approval, reconfiguring after an inverter replacement where original settings were not transferred.
Why export limit problems are so common after inverter replacements
SolarEdge HD-Wave inverters have a documented failure rate, and warranty replacements are routine. The problem is that the export limit configuration lives in the inverter — not in the monitoring portal. When a new inverter is fitted, the export limit must be reconfigured from scratch by the installer using SetApp. If the replacement engineer does not have the original DNO approval documents or does not realise an export limit was configured, the new inverter may ship with no limit (violating G99) or with a fixed limit instead of dynamic.
The homeowner often does not notice immediately because the system is generating again. The curtailment only becomes apparent weeks or months later when someone checks the monitoring data and sees the characteristic flat-line during peak production. By that point, significant generation has been wasted.
This also happens when an installer goes out of business and the homeowner cannot get SetApp access to check or modify the configuration. The export limit settings are locked behind the installer's account, and SolarEdge does not provide homeowner access to these parameters. An independent engineer with their own SetApp installer credentials can take over the system configuration and correct the settings.
Export limit — common questions
An export limit controls the maximum power the inverter sends to the grid. UK systems above 3.68 kW single-phase need G99 approval, which typically includes an export limit condition. SolarEdge uses a revenue grade meter or CT clamp at the grid connection point to measure real-time export — the inverter reduces output when the limit is reached. The limit only affects grid export, not total generation, so the system still produces power for self-consumption.
The most common cause is the meter or CT clamp communication has failed. When the inverter loses contact with the export meter, it falls back to fixed limiting — a hard cap on total output regardless of self-consumption. Other causes include reversed CT clamp orientation, the limit set to zero, or the system configured for fixed mode instead of dynamic. An installer with SetApp access can check and correct the configuration.
No. SolarEdge locks export limit settings behind installer-level authentication in SetApp. Homeowners can view monitoring data but cannot access configuration menus for export limiting, meter setup, or grid compliance. This is a safety measure — incorrect settings can violate your G99 agreement. If changes are needed, a qualified installer with SetApp access must make the adjustment. STS can do this remotely in most cases.
G98 covers systems at 3.68 kW or below per phase — these use a simplified notification process and do not typically need export limiting. G99 covers systems above that threshold and requires prior DNO approval. Most G99 approvals include an export limit, usually set to 3.68 kW to match the G98 threshold. Some DNOs approve higher limits or zero export depending on the local network conditions.
A correctly configured dynamic limit causes minimal loss — it only curtails when export exceeds the limit and household consumption is low. If the configuration is wrong and the system is using fixed limiting or the meter has failed, losses can reach 20–40% of potential generation during summer peak hours. STS analyses your monitoring data to calculate the exact loss and provide evidence of the misconfiguration.
Export limit wrong? We fix it remotely via SetApp.
We review your monitoring data to quantify the generation loss, check the export limit configuration, and correct the settings — without a site visit in most cases.