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Fault guide · GivEnergy Hybrid, AIO & AIO 2

GivEnergy Solar Not Generating — Zero or Low Output

Your panels are on the roof and the sun is shining — but the GivEnergy portal shows zero, or a fraction of what you'd expect. In the majority of cases this is a configuration issue that can be fixed in minutes without an engineer. This guide works through every cause in order of likelihood, starting with the most common.

Export limit — the most common cause Grid overvoltage and curtailment explained Hardware faults and when to escalate
Solar stopped generating or never worked?

If you've checked the export limit and DC isolator and the system still shows zero output, the portal event log usually identifies the fault without a site visit. We review generation history, fault codes, and configuration changes remotely to confirm whether hardware is involved before recommending an engineer.

Not affiliated with GivEnergy Ltd. Independent diagnosis and repair.

ZERO GENERATION

Portal shows 0W on a sunny day

The GivEnergy app or portal shows no solar output despite panels being installed and it being a clear day. This is almost always the export limit set to 0W, the DC isolator switched off, or the inverter in standby mode — all fixable without a site visit.

LOW GENERATION

Output well below what panels should produce

Generation is happening but the numbers are much lower than expected — or the system produces normally in the morning and stops in the afternoon. The classic afternoon drop is grid overvoltage: the inverter disconnects when grid voltage exceeds 253V.

CLIPPED OUTPUT

Generation capped at a specific wattage

The portal shows solar output hitting a ceiling (e.g. exactly 3.68kW regardless of sun) and staying flat. This is curtailment — either an export limit in settings, a G99 export restriction from your DNO, or demand-side capping when the battery is full and export is restricted.

Generation vs self-consumption. The GivEnergy portal shows both solar generation (what the panels produce) and self-consumption (how much of that generation the house actually uses). If the battery is full and export is limited, generation may appear very low even though panels are working — the inverter is clipping output to match consumption. Always check the Solar figure on the portal dashboard, not the self-consumption figure, when diagnosing generation issues.
Start here
Quick checks

Three checks that resolve most cases immediately

Before going deeper, confirm these three things — they account for the large majority of zero-generation reports we receive.

1
Is it actually daylight and not overcast?

Standard solar panels produce very little output below approximately 200W/m² irradiance. On a heavily overcast UK day, a 4kWp system may only produce 100–300W total — which can look like near-zero in the portal. Check the generation against expected irradiance for today's conditions before assuming a fault. Use the GivEnergy portal's historical comparison to see whether generation matches seasonal norms.

2
Check the export limit — the most common cause

Log into givenergy.cloud → My Inverter → Settings → Export Limit. If this is set to 0W, the inverter will not push any power to the grid. On a sunny day with a full battery, this causes the inverter to clip all solar generation to match only the instantaneous house load — so the portal shows the panels producing, say, 400W instead of the 4,000W they could produce. Increase the export limit to 3,600W or the maximum your DNO connection allows.

Why is it set to 0W? This is the default on some installations — installers sometimes set it to 0 if the customer hasn't registered for a Smart Export Guarantee (SEG) tariff. It also gets reset to 0 by some third-party smart tariff integrations. Check both the portal and the app — the app sometimes shows a different cached value.
3
Check the portal event log for fault codes today

In the portal: My Inverter → Event Log. Switch the view to today and look for F01 (grid voltage), F04 (isolation fault), or any fault listed at the time generation stopped. A single F01 at 13:45 and zero solar output from that point is diagnostic of grid overvoltage. Record the code and time — the GivEnergy fault code index gives the specific recovery path for each code.

Cause 1 — most common
Export limit

Export limit set to 0W — inverter clipping solar output

An export limit of 0W is the single most common cause of GivEnergy showing very low or zero generation on a bright day. The inverter is working correctly — it is simply constrained from exporting, so it clips solar output to exactly what the house can consume at any instant.

How export limiting clips solar generation

What happens

The GivEnergy inverter monitors live house consumption via the CT clamp. With export limit = 0W, the maximum solar output the inverter will produce at any moment equals exactly the house consumption reading.

On a sunny afternoon when the house uses 400W and the battery is full: the inverter clips 3,600W of potential solar generation. The portal shows 400W solar — making it look like the panels are barely working.

How to fix it
1. Log into givenergy.cloud
2. Go to My Inverter → Settings → Export Limit
3. Change from 0W to your agreed export value — 3,600W is standard for single-phase G98 connections; check your DNO connection agreement if unsure
4. Click Submit and wait 2–3 minutes for the change to apply
5. Refresh the portal dashboard — solar generation should rise immediately on a bright day

Before raising the export limit: Confirm your property has an active Smart Export Guarantee (SEG) tariff or export agreement in place. Exporting without an SEG means you are giving electricity to the grid without payment. Octopus, E.on, OVO, and most major suppliers offer SEG tariffs — register for one before enabling export. See the export limit configuration guide for full details.

Cause 2
DC isolator

DC solar isolator off or PV MCB tripped

The PV DC isolator disconnects the solar panels from the inverter. If it is in the OFF position — either accidentally or following a maintenance visit — the inverter has no solar input and will show zero generation regardless of sun conditions.

Which systems have a DC isolator? The GivEnergy Hybrid Inverter (all generations) and the AIO 2 + MPPT are DC-coupled — solar panels connect directly to the inverter via DC. Check the DC/PV isolator on these systems. The standard GivEnergy AIO (All-in-One, non-MPPT) is AC-coupled — solar panels connect via a separate PV inverter, and the AIO itself has no DC solar input. If you have a standard AIO, check the separate PV inverter on the wall or in the cupboard.
Where to find it
Hybrid inverter: Rotary switch near the inverter labelled PV, DC, or Solar. ON = vertical/line symbol.
AIO unit: On the base or side of the unit, sometimes inside a cover. Also check for a PV MCB inside the unit's DC compartment.
Roof isolator: Some installations have a second DC isolator near the panels on the roof or in the loft. This must also be ON.
Consumer unit: There may be a PV or Solar MCB in the consumer unit that trips independently of the rotary isolator.
What to do
1

Check all DC isolators are in the ON position (line symbol / vertical)

2

If a rotary isolator is stuck or damaged, do not force it — call an electrician

3

Check the PV MCB in the consumer unit — reset if tripped and observe whether it holds

4

If the MCB trips again immediately on reset, there is a DC-side fault — do not re-energise without an engineer inspection

5

After correcting, wait 2–3 minutes for the inverter to detect solar input and begin generating

Cause 3
Overvoltage

Grid overvoltage — inverter disconnecting mid-afternoon

Under UK grid code G98/G99, GivEnergy inverters must disconnect and stop generating if the grid voltage rises above 253V. This is not a fault — it is mandatory protection. But it causes real lost generation and is common in areas with dense solar installations.

How to identify grid overvoltage

Pattern

Generation is normal in the morning, then drops suddenly in the afternoon (typically 11:00–16:00 on sunny days). The cut-off point varies — it depends on when grid voltage peaks on your local network.

Confirm it

Open the portal event log (My Inverter → Event Log) and filter to today. Look for F01 fault code entries — grid voltage fault. These will appear at the exact times generation stopped. The fault code description may also show the measured voltage (e.g., "Grid overvoltage: 256V").

Action

Contact your Distribution Network Operator (DNO) — Western Power Distribution, UK Power Networks, Northern Powergrid, etc. They are legally obliged to investigate persistent overvoltage on the network. Reference the fault codes and dates from your portal. If your property is on a long rural spur, a voltage optimiser or a G100 export limitation device may be required as an interim measure.

Active Voltage Management (AVM): Some GivEnergy systems can use reactive power (VAr) compensation to reduce effective voltage at the inverter's connection point. This is a G99 grid connection option — ask your DNO or a G99-qualified engineer whether your installation can have AVM enabled. It reduces disconnections without needing hardware changes.

Cause 4
Curtailment

Solar clipping when battery is full and export is limited

Even with a non-zero export limit, solar generation will be curtailed when the battery reaches 100% and house consumption is lower than the solar potential. This is normal inverter behaviour — not a fault. But it looks alarming in the portal.

Understanding when curtailment is normal vs a fault

Situation Portal shows Status
Battery 100%, house uses 400W, export limit 3.6kW Solar: 4,000W+, export: 3,600W Normal
Battery 100%, house uses 400W, export limit 0W Solar: 400W (clipped) Curtailed — fix export limit
Battery 50%, house uses 400W, export limit 0W Solar: 3,000W (charging battery) Normal — battery charging
Battery 100%, export limit 3.6kW, G99 cap 3.68kW Solar flatlined at exactly 3.68kW Normal — G99 cap active

If your installation is under a G99 limited export connection (common for systems over 3.68kW single-phase), the DNO may have set a maximum export cap that the inverter enforces permanently. This is correct operation — the limit is in your grid connection agreement, not the GivEnergy settings.

Cause 5
Standby mode

Inverter in standby, Off mode, or overridden by external API

The GivEnergy portal's Remote Control section allows the system mode to be set to Off or Standby — which stops generation entirely. Third-party integrations including Octopus smart tariffs, Home Assistant, and demand charge programmes can also push this state without the homeowner being aware.

Check and reset via the portal

1
Go to Remote Control in the portal

Log into givenergy.cloud → My Inverter → Settings cog → Remote Control. This shows the live state of system controls, not just the scheduled settings.

2
Check System Mode is not Off or Standby

Click the Refresh button next to System Mode to fetch the live value — the displayed value can be stale. If it shows Off, Standby, or Import Only, change it to Normal (Self Consumption) and click Submit.

3
Confirm Battery Pause is set to Not Paused

Click Battery in Remote Control. Refresh the Pause Battery value — if it shows Paused, change to Not Paused and submit. A paused battery with a full SoC will not permit solar charging and may cause the inverter to curtail generation.

4
Disable third-party integrations temporarily

If you have Octopus Intelligent, Home Assistant, GivTCP, or any other third-party connection to the GivEnergy API, temporarily disconnect or pause it. Some integrations set the export limit or system mode as part of their scheduling. If generation resumes after disconnecting the integration, the integration is the cause — reconfigure its export limit settings.

Cause 6
Hardware faults

Hardware and wiring faults that cause zero generation

If all software and configuration checks have been completed and generation remains at zero, the fault is likely hardware. These cannot be diagnosed from the portal and require an engineer — but we can usually confirm whether hardware is the cause from monitoring data before a site visit.

MPPT fault — inverter cannot read PV input

Engineer required

GivEnergy inverters have one or two Maximum Power Point Trackers (MPPT) that convert the variable DC output from panels into usable power. An MPPT fault or failed input stage means the inverter receives no usable solar input even though panels are live.

The portal will show 0W PV input with no fault code — the inverter is running, connected to the grid, but not processing any solar.

Portal indicators
PV voltage reading is 0V or very low on a sunny day
Battery charging and grid connection normal
No F-code faults in event log
Problem present across all lighting conditions

DC wiring fault — panels not reaching inverter

Engineer required

Corroded DC connectors (MC4 connectors on the panel strings), reversed polarity on a string, or a failed isolator can all prevent solar DC from reaching the inverter input. This is also the failure mode after roofing work — roofers sometimes damage DC cables.

Portal indicators
PV voltage is lower than expected for the panel count
One MPPT input shows 0V, the other reads normally
Generation fell suddenly following roof work or storm

Failed panels or shading

Inspect or test

Individual panel failures (failed bypass diodes, delamination, cell cracking) reduce string output significantly. A single failed panel in a series string reduces the entire string's output. Chronic shading from new nearby structures has the same effect.

Portal indicators
Gradual year-over-year decline in generation
Morning generation fine, afternoon lower than expected
Visible soiling, bird mess, or debris on panels
When to escalate
Escalate

When to call STS — beyond the self-help checks

The configuration checks above resolve the majority of zero-generation reports. If you've worked through them and generation is still missing, the portal monitoring data usually points directly to the cause — without a site visit.

Call STS — safety-related faults

F04 isolation fault code in the portal — do not reset, indicates DC insulation failure
PV MCB trips immediately on reset — DC-side wiring fault, do not re-energise
Burning smell, discolouration, or scorch marks near the inverter or isolators
Zero generation immediately after roofing or building work — check for cable damage

Call STS — diagnostic support

Export limit is correct, DC isolators are on, no fault codes — still 0W solar
Persistent F01 overvoltage faults — portal logs to support a DNO complaint
Generation dropped suddenly and coincided with a firmware update or tariff change
System has never generated since installation — installer unresponsive
One MPPT string generating and the other showing 0V on a bright day
We review your generation data before sending anyone out

A remote session pulls the portal event log, generation history, PV voltage readings, and settings audit trail. In most cases we can confirm within 30 minutes whether the fault is configuration, grid-side, or hardware — and whether an engineer visit is actually needed. From £75.

Book remote diagnostic →
FAQ
FAQ

GivEnergy solar generation questions answered

Start with the export limit in the portal (givenergy.cloud → My Inverter → Settings → Export Limit). If this is set to 0W, the inverter actively caps solar output at zero whenever it cannot consume the generation internally. The second check is the DC isolator — confirm it is switched ON. If both are fine, check the portal event log for F01 fault codes (grid overvoltage), which silently disconnect the inverter from the grid during sunny periods.

This is the classic signature of grid overvoltage (F01 fault). In the afternoon, grid voltage typically rises as many solar systems export simultaneously. When voltage exceeds 253V, GivEnergy inverters disconnect to comply with G98/G99 regulations. You will see F01 entries in the portal event log at the times generation stops. Check your portal and report persistent F01 faults to your DNO — they are legally required to investigate. A G100 export limitation device may be offered as an interim measure.

Not necessarily. When the battery is 100% charged and the export limit is set to 0W, the inverter clips solar output to match only what the house is currently consuming. If your house uses 300W and your panels could produce 4kW, the inverter limits generation to 300W. This appears as low or fluctuating solar output on a bright day. It is not a fault — it is the export limit working as configured. Raise the export limit if you want to sell excess generation to the grid (requires an active SEG tariff).

Yes, though indirectly. Firmware updates sometimes reset settings including the export limit (which may revert to 0W) or system mode (which may switch to Standby). If generation stopped shortly after a firmware update notification appeared in the portal, check the export limit, system mode, and Remote Control settings. A remote diagnostic can review the portal event log to confirm exactly what changed and when.

Zero generation from day one indicates an installation fault. Common causes include: DC isolator left in the OFF position by the installer; PV strings wired with reversed polarity; MPPT configuration mismatched to panel count; or export limit set to 0W with no house loads running at time of commissioning. Contact your installer in the first instance. If they are unresponsive or have gone out of business, see our installer gone bust guide — STS can perform an independent post-installation inspection.

If the portal shows generation but bills haven't reduced, the most likely cause is a CT clamp installed on the wrong cable — measuring grid flow instead of solar output. It can also mean generation is real but being exported to the grid without you receiving SEG payments. Compare the portal's self-consumption figure against your electricity meter readings over a week to identify the discrepancy. A remote diagnostic can confirm which CT is measuring what from the data patterns.

Independent GivEnergy support

Panels still not generating after checking everything?

A remote diagnostic reviews your portal generation history, PV voltage logs, fault code timeline, and settings audit trail. In most cases we establish the cause without a site visit — and confirm whether an engineer is actually needed before you pay for one.

Solar Health Plan

Independent of GivEnergy Ltd. Results from your own portal data.

This is a brand-specific version of our general system not producing guide, which covers all brands.