Solar Panel Producing Low Power? Check Solar Irradiance Before Troubleshooting Malaysia
Solar Panel Producing Low Power? Check Solar Irradiance Before Troubleshooting Malaysia
Your solar PV system appears to be producing less power than expected.
Does this mean the solar panel is faulty?
Not necessarily. Before blaming the module, check the environmental conditions under which the PV system is operating.
One useful measurement is solar irradiance in W/m².
A solar irradiance meter measures the solar power reaching a surface and can provide important context when technicians investigate low PV output.
For portable field measurements, the VICI LX-107 Solar Power Meter can be used for solar radiation measurement during PV inspection and troubleshooting.
Quick Answer: Why Is My Solar Panel Producing Less Power?
Lower PV output can have many possible causes.
These may include:
Low solar irradiance
Cloud cover
Partial shading
Dirty solar panels
High module temperature
Module condition
Cable problems
Connector problems
String differences
Inverter conditions
Other electrical or system issues
The first mistake is assuming that every low-output reading means the panel itself has failed.
The measurement conditions need to be understood first.
Start by Measuring Solar Irradiance
Solar irradiance describes the incident solar power per unit area.
It is commonly measured in:
W/m² – watts per square metre
If the available solar radiation is low when the PV output is measured, reduced electrical output may be expected.
If irradiance is relatively strong but PV performance remains unexpectedly low, further investigation may be justified.
This makes irradiance a useful starting measurement during troubleshooting.
Low Output + Low Irradiance
Consider this situation:
A technician visits a factory rooftop PV system because production appears lower than expected.
The weather is partly cloudy.
The technician measures the available solar radiation and finds that irradiance is relatively low at that moment.
This information changes how the electrical measurement should be interpreted.
Low PV output during weak solar conditions is not automatically evidence of a defective module.
The technician should document the conditions and continue the investigation appropriately.
Low Output + Strong Irradiance
Now consider another situation.
The solar irradiance is relatively strong, but one part of the PV installation appears to be performing abnormally.
This may justify further investigation.
Depending on the system, technicians may check:
Module cleanliness
Shading
DC voltage
DC current
String performance
Cable condition
Connectors
Module temperature
Thermal patterns
Insulation
Inverter information
Solar irradiance does not tell you which component is faulty.
It helps establish whether available sunlight may be influencing the result.
Problem 1 – Passing Clouds
Passing clouds are one of the simplest reasons PV readings can change during field testing.
A technician may take one measurement under strong sunlight and another several minutes later when a cloud covers the array.
If the environmental conditions are not recorded, the two electrical results can be difficult to compare meaningfully.
Better Practice
Record:
Time
Solar irradiance in W/m²
PV electrical measurements
Weather condition
Take related measurements as close together in time as practical.
Problem 2 – Partial Shading
Shading can come from more places than trees.
On commercial and industrial rooftops, possible sources include:
Water tanks
Ventilation equipment
Exhaust systems
Antennas
Adjacent buildings
Roof structures
New equipment
Temporary objects
Shading may also change according to the time of day.
Visual inspection should therefore form part of PV troubleshooting.
Problem 3 – Dirty Solar Modules
Dust, dirt, bird droppings and other contamination can reduce the solar radiation reaching parts of a PV module.
Industrial environments may make this particularly relevant.
If contamination is suspected, technicians can compare system condition before and after appropriate maintenance while considering the corresponding environmental conditions.
Do not assume that every performance problem is electrical.
Problem 4 – Module Temperature
Strong sunlight does not mean module temperature is irrelevant.
PV modules can become hot during operation.
Temperature can influence PV electrical characteristics, so more detailed troubleshooting may require both:
Solar irradiance measurement
and
Temperature measurement
This provides more environmental information when interpreting electrical test results.
Problem 5 – Electrical Connections
If environmental conditions do not explain the observed problem, technicians may need to investigate electrical components.
Depending on the system and authorised maintenance procedure, these may include:
PV connectors
DC cables
Junctions
Strings
Combiner equipment
Inverters
Protection devices
Use the appropriate electrical testing equipment and follow the required safety procedures.
Problem 6 – Uneven Performance Between PV Areas
Large factory rooftops may contain arrays facing different directions or experiencing different shading conditions.
Do not automatically assume that measurements from one location represent the entire roof.
A portable irradiance meter allows technicians to take spot measurements at different locations when required.
For meaningful comparison, maintain consistent measurement methods and consider sensor orientation.
How to Use a Solar Irradiance Meter During Troubleshooting
A basic workflow is:
Step 1 – Inspect the Site
Look for obvious shading, contamination or physical problems.
Step 2 – Measure Solar Irradiance
Measure solar radiation in W/m².
Step 3 – Record Weather and Time
Solar conditions can change quickly.
Step 4 – Measure Relevant PV Parameters
Take the required electrical and temperature measurements using appropriate instruments.
Step 5 – Compare the Results
Interpret electrical measurements in the context of irradiance and other environmental conditions.
Step 6 – Investigate Abnormal Areas
If the results indicate a potential problem, continue with the appropriate PV diagnostic procedure.
Do not diagnose a PV fault from the irradiance reading alone.
VICI LX-107 for Solar Troubleshooting
The VICI LX-107 Solar Power Meter is designed for portable solar radiation measurement.
Useful functions include:
W/m² Measurement
Provides solar power measurement per unit area.
BTU Display
Provides an additional unit for relevant applications.
MAX / MIN
Useful for observing changes in solar radiation during a measurement period.
Data Hold
Allows a displayed reading to be held for easier recording.
For technicians moving between multiple PV measurement locations, the portable format can be convenient.
Solar Irradiance Meter + Thermal Camera
These two instruments can provide different information during PV troubleshooting.
Solar Irradiance Meter
Answers:
“How much solar radiation is available?”
Thermal Camera
Helps answer:
“Are there unusual temperature patterns?”
Neither measurement alone provides a complete PV diagnosis.
Together with electrical measurements, they can contribute to a more systematic inspection.
Solar Irradiance Meter + DC Clamp Meter
A DC clamp meter and irradiance meter also measure different things.
Irradiance Meter → W/m²
DC Clamp Meter → electrical current
Comparing environmental and electrical information can help technicians interpret PV operating conditions more effectively.
A Better PV Troubleshooting Record
Instead of writing only:
“Solar output low.”
record:
Date: __________
Time: __________
Weather: __________
Solar irradiance: __________ W/m²
Module temperature: __________ °C
DC voltage: __________ V
DC current: __________ A
String / Array: __________
Visible shading: Yes / No
Module contamination: Yes / No
Remarks: __________
This creates a much more useful maintenance record for future comparison.
Factory Rooftop Solar Troubleshooting Malaysia
The approach is particularly relevant to industrial rooftop PV.
Factory engineering and facility teams may need to investigate performance while dealing with:
Large roof areas
Multiple PV strings
Industrial contamination
Rooftop equipment
Changing shading
High outdoor temperatures
Rapidly changing weather
Portable test instruments allow maintenance personnel to investigate specific areas instead of relying only on overall system production data.
Can LX-107 Tell Me Whether a Solar Panel Is Damaged?
No.
The LX-107 measures solar power.
It should not be presented as a complete solar panel fault detector.
If a technician suspects module damage or another PV fault, additional inspection and appropriate testing equipment will be required.
This distinction is important when selecting equipment.
When Is the LX-107 a Good Fit?
The VICI LX-107 is worth considering when the requirement is:
Portable solar irradiance spot measurement
W/m² measurement
Rooftop solar inspection
Solar installation work
PV maintenance
Solar radiation comparison
Research or technical applications
If the requirement involves advanced PV analysis, continuous monitoring or specialised electrical tests, additional equipment may be necessary.
Solar PV Troubleshooting Equipment Supplier Malaysia
MTM Precision supplies testing and measurement instruments for:
Solar installers
PV O&M contractors
Electrical contractors
Factory engineering teams
Facility maintenance
Industrial maintenance
Universities and technical users
Customers can contact MTM Precision for the VICI LX-107 Solar Power Meter and other instruments required for solar PV inspection and troubleshooting.
Contact MTM Precision
MTM Precision Sdn Bhd
Website: www.mtmpre.com.my
Email: mtmpre@yahoo.com
WhatsApp: 016-660 7346
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia.
Serving customers throughout Selangor, Kuala Lumpur, Johor, Penang, Perak, Negeri Sembilan, Melaka, Pahang, Kedah, Perlis, Terengganu, Kelantan, Sabah and Sarawak.
Solar panel output lower than expected? Measure the operating conditions before drawing conclusions. Contact MTM Precision for VICI LX-107 Solar Power Meter availability and suitable PV testing instruments in Malaysia.
08 Sep 2026
