spectral pyranometer


The SolarSIM-GPV is a Class A pyranometer that also provides the PV professional with everything they need to fully quantify the spectral impact of their solar resource.

The SolarSIM-GPV employs Spectrafy’s patented SolarSIM multi-spectral measurement technology to bring routine solar spectral measurement to the PV industry.

Measurands: Global solar irradiance (horizontal or tilted), PV spectral correction factors
Technology: Software-augmented multi-filter radiometer.
Highlights: Broadband irradiance and spectral correction factors in a single sensor. Makes spectrally corrected irradiance measurement reliable, routine and affordable for the PV industry.
ISO9060:2018: Class A, spectrally flat for sunlight, fast-response optional.

The next step in pyranometer technology.

PV is inherently spectral. Sunlight is a spectral fuel source and solar panels are spectrally selective, so it makes sense that the sensors used to measure sunlight should be spectral too.

Yet for a longest time, the PV industry has had to rely on spectrally-blind sensors to measure sunlight. This disconnect leads to spectral uncertainty that can exceed 4% on an annual basis and over 20% on an instantaneous basis. As the PV industry continues to rapidly evolve, spectral uncertainty is limiting returns for developers and owners alike.

Enter the SolarSIM-GPV, the next step in pyranometer technology. The SolarSIM-GPV uses multi-spectral measurement technology to make the elimination of spectral uncertainty a reality for the PV industry while also providing the highest quality of Class A solar irradiance data.

The SolarSIM-GPV uses filtered photodiodes to make precise, multi-spectral measurements of the solar spectrum. These measurements are then used to resolve the complete solar spectrum and total irradiance. The spectral data is then automatically distilled into intuitive spectral correction factors that are easily implemented in existing industry software.

This SolarSIM-GPV’s powerful combination of multi-spectral measurement and spectral data processing delivers a powerful new tool for the PV industry and a big step forward for pyranometer technology – a spectral sensor for a spectral industry.

The SolarSIM-GPV produces data that no other pyranometer can.

Global horizontal (or tilted) irradiance ISO9060:2018 Class A measurements of global irradiance (horizontal or tilted), under all sky conditions, covering the complete 280-4000nm solar spectral range.
Spectral correction factors for PV Automated calculation of spectral correction factors for up to nine embedded or user-defined solar panels.
Meteorological parameters Ambient temperature, relative humidity and atmospheric pressure.

The SolarSIM-GPV comes with powerful software to process and visualize your data.

The SolarSIM-GPV comes with powerful software to process and visualize its data
The SolarSIM-GPV software sits-offboard the sensor and processes the raw irradiance measurements to generate the various data streams. A Windows-based GUI provides the user with easy visualization of the SolarSIM-GPV’s data streams. A command line version of the software is also available for network and datalogger-based applications.

Multiple options for maximum ease.


With RS-485 ASCII digital output, the SolarSIM-GPV can connect to any RS-485 capable datalogger. Sample datalogger code is available upon request.


Get your SolarSIM-GPV working straight out of the box with our custom power/comms converter. The Combox allows you to connect to and power a SolarSIM-GPV directly through a laptop or PC.

Serial over ethernet

The SolarSIM-GPV can be connected to a networked PC/server via a suitable SoE device. Hardware recommendations are available upon request.

iSG Integrated Spectrum Generator

The iSG Integrated Spectrum Generator allows processed data (global irradiance, spectral correction factors) to be transmitted directly to an onsite datalogger via RS-485 Modbus RTU, eliminating the need for additional processing hardware or software.

Broadband Irradiance

Spectral range 280 – 4000 nm
Maximum Irradiance 2000 W/m2
Response Time (95%) 0. 7s (0.4s optional)
Zero offset A n/a
Zero offset B n/a
Non-stability (change per year) < 0.2%
Non-linearity < 0.3%
Spectral error < 0.5%
Temperature response 0.1% (on-board temp. correction)
Directional/cosine response 10 W/m2
Tilt response n/a
Calibration uncertainty 1.1%
ISO 9060:2018 classification Class A
ISO 9060:2018 sub-category: “Spectrally flat” Compliant for sunlight
ISO 9060:2018 sub-category: “Fast response” Optional

Spectral correction factors

umber of panels 9, user defined
Method Derived from IEC 60904-7
Calculation process Automated


Weight 1.2 kg
Dimensions 132 x 132 x 110 mm
Power consumption 12 VDC, < 1W
Communication RS-485 ASCII, Direct to PC, serial over ethernet, datalogger
Operating temperature range -30 to 65 °C

The PV professional's SolarSIM.

Solar resource assessment Use spectrally corrected irradiance data to reduce the uncertainty in your PV performance predicitons. Accurately quantify the spectral performance at your site for any solar panel technology.Reduce the uncertainty in your PV performance predictions. Accurately quantify the spectral performance boost at your site for any solar panel technology.
Solar power plant O&M The SolarSIM-GPV enables greater clarity PV O&M metrics by eliminating spectral noise in real time. Analyze your plant's performance under all sky conditions and time scales. Realize more accurate analysis of panel degradation rates.
Bifacial PV Accurately quantify the rearside solar resource potential for bifacial PV.
PV panel inventory deployment optimization Match your PV panel inventory with the optimal sites in your project pipeline to ensure maximum overall electricity and revenue generation.
Refine warranty claims Reduce the uncertainty in PV panel and inverter warranty claims.
Spectral hedging Build value in your PV plant by banking the spectral datasets needed for accurate repowering assessments in the future.
Solar R&D The SolarSIM-GPV enables R&D departments to accurately quantify the effects of spectral variability on their solar technologies.

Why would I choose the SolarSIM-GPV over a traditional thermopile pyranometer?

Thermopile pyranometers do a good job of measuring broadband irradiance, but are spectrally blind and are unable to quantify spectral effects. Failing to account for spectral effects introduces spectral uncertainty into PV performance models and operating metrics. Spectral uncertainty can be as high as 5% on an annual basis, or up to 40% on an instantaneous basis. The SolarSIM-GPV allows users to accurately quantify and eliminate spectral uncertainty leading to improved performance prediction and analysis. The SolarSIM-GPV is the only Class A pyranometer that provides the capability to accurately quantify broadband irradiance and spectral effects within a single sensor.

How does the SolarSIM-GPV work?

The SolarSIM-GPV is a software augmented multi-filter radiometer. It uses filtered photodiodes to make precise, multi-spectral measurements of the solar spectrum in several narrow wavelength bands. These measurements then inform the SolarSIM-GPV’s software to accurately resolve the complete global solar spectrum and total global irradiance (GHIGTI), under all sky conditions. The SolarSIM-GPV's software uses the spectral irradiance data to automatically calculate PV spectral correction factors for up to nine user-defined solar panels. The GHI/GTI and spectral correction factors are then output to the user and can be easily implemented within industry-standard PV modelling software.

What are PV spectral correction factors?

Spectral correction factors (SCFs) quantify the changes in PV panel performance due to the difference between the sun’s spectrum in real-life and the reference spectrum that all solar panels are rated under. The spectral impact on PV performance can reach 5% on an annual basis and up to 40% on an instantaneous basis.

Is the SolarSIM-GPV a Class A pyranometer?

Yes, the SolarSIM-GPV is fully compliant with ISO9060:2018 Class A instrument performance criteria. In addition, ISO9060:2018 specifies sub-classifications of
'spectrally flat' and 'fast response'. The SolarSIM-GPV is spectrally flat for sunlight and a 'fast response' version of the SolarSIM-GPV is available as an option.
The SolarSIM-GPV is the only Class A pyranometer that is able to accurately resolve both broadband irradiance and PV spectral correction factors.

Why do I need spectrally corrected irradiance data?

PV is an inherently spectral technology. The sun is a spectral, and spectrally variable fuel source. Solar panels are spectrally selective absorbers. Failing to quantify spectral effects leads to spectral error, or uncertainty, in PV performance models and operating metrics. This spectral error can vary from as high as 5% on annual basis to over 40% on an instantaneous basis. The SolarSIM-GPV allows the user to accurately quantify and eliminate spectral uncertainty, allowing for improved performance prediction and analysis.

Does Spectrafy sell complete measurement systems?

Yes, we can provide you with a complete turn-key met station for your PV plant or solar resource assessment campaign.

How do I connect a SolarSIM-GPV to my datalogger?

The SolarSIM-GPV communicates via RS-485 ASCII. As such it can connect to any datalogger that accepts RS-485 or RS-232 inputs. Sections 4 and 6 of the SolarSIM-GPV User Manual provides details regarding data logger integration, as do our data logger app notes found in the SolarSIM-GPV download section.

How is the SolarSIM-GPV calibrated?

All SolarSIM-GPV production units undergo electrical, thermal and optical calibration. The optical calibration is performed on-sun against our reference SolarSIM-G sensors The reference sensors are calibrated for absolute irradiance at NREL in Golden Colorado and are traceable to NIST Spectral Irradiance Standard Model FEL lamps.

How often should I get my SolarSIM-GPV recalibrated?

We recommend recalibration every two years in order to ensure the highest measurement accuracy. Recalibration is performed on-sun, at Spectrafy HQ in Ottawa, Canada. Please contact us prior to shipping your unit in order to ensure the swiftest calibration process possible.

How do I integrate the SolarSIM-GPV into my SCADA system?

The SolarSIM-GPV can communicate with any datalogger that accepts RS-845 sensors. Alternatively, an off-the-shelf, serial-over-ethernet converter can be used to enable direct LAN integration.



The Combox is a power and comms converter that allows the user to connect to and power their SolarSIM directly through a PC or laptop.
iSG Integrated Spectrum Generator

iSG Integrated Spectrum Generator

The iSG enables the SolarSIM-GPV to output processed data (global irradiance, spectral correction factors) directly to a datalogger via RS-485 Modbus RTU, without the need for additional processing hardware and software.
MP-G Mounting Plate

MP-G Mounting Plate

We offer a range of standard, anodized aluminum mounting plates suitable for mounting the SolarSIM-G series sensors. Custom options are also available.
GV-1 Ventilator

GV-1 Ventilator

The GV-1 ventilator maximizes the reliability and accuracy of SolarSIM-G, SolarSIM-GPV, SolarSIM-UV and SolarSIM-ALB measurements while minimizing maintenance, by reducing the effects of dust, raindrops and dew.
SolarSIM-E Automated shadowband

SolarSIM-E Automated shadowband

The SolarSIM-E leverages the SolarSIM-G to enable accurate and affordable measurements of full range spectra and broadband irradiance for all three irradiance components (global, diffuse and direct).
TMP-G Tripod Mounting Platform

TMP-G Tripod Mounting Platform

Our tripod mounting platform with integrated mounting plate, provides a rugged, easily installed solution for deploying your SolarSIM-G, SolarSIM-GPV or SolarSIM-UV sensor in the field.
ST-5 Sun Tracker

ST-5 Sun Tracker

The optimum combination of performance, reliability and cost. Combine with the SolarSIM-D2. Combine with the SolarSIM-G, SolarSIM-GPV or SolarSIM-UV for direct global or single-axis tracked plane-of-array irradiance measurements.
CC-G Carry Case

CC-G Carry Case

Hard plastic, waterproof, shockproof and dust proof carry case with custom foam cut outs to keep your SolarSIM-G/GPV/UV/GE safe and snug.
Data loggers

Data loggers

Spectrafy offers a range of third-party dataloggers preconfigured with the data logger code required to interact with the SolarSIM sensors.