Hukseflux SR30-D1 Solar Irradiance Sensor User Manual
- June 1, 2024
- Hukseflux
Table of Contents
Hukseflux SR30-D1 Solar Irradiance Sensor
Solar irradiance sensor (pyranometer) calibration services, all brands, for
PV system asset management
System performance monitoring nowadays requires regular pyranometer
calibration
Solar radiation measurement is a cornerstone of the Performance Ratio (PR)
measurement of a PV power plant. It also is the weakest link. This is why the
latest versions of the IEC 61724-1 (2017 and 2021) require regular pyranometer
calibration. This means sending instruments to a lab. Our worldwide
calibration and servicing organisation is at your disposal.
Introduction
In utility scale PV system performance monitoring the solar irradiance is
nowadays measured with pyranometers. The PR calculation essentially takes the
system’s electrical output and divides it by irradiance. The PR is a key
performance indicator of the PV system’s performance. Accurate day-to-day and
year-to-year PR records also increase the PV system value.
The IEC 61724-1 standard update
The first edition of IEC 61724-1: Photovoltaic system performance monitoring –
Guidelines for measurement, data exchange and analysis –, dates from 2008. The
updated 2017 and 2021 versions of the standard are fundamentally different
from the 2008 version. The new scope not only defines the measuring system
components and procedures (as in the 2008 version), but it also aims to keep
measurement errors within specified limits.
In the new standard regular recalibration of pyranometers is a requirement.
Why calibration?
Regular calibration is part of quality management for all “mission-critical”
measuring instruments. Its purpose is to verify that the measurement
instrument has been and will be stable and, if not, to correct for this.
Pyranometers, due to prolonged exposure to the sun, are not expected to be
perfectly stable. To attain the high accuracy necessary and to monitor PV
system performance and degradation, you must frequently recalibrate
pyranometers. Before calibration, the laboratory performing the calibration
will also assess the condition of the pyranometer dome. If needed, a desiccant
is replaced.
How often?
Most instrument owners use a calibration interval of 1 year for all their
instruments. With pyranometers, the manufacturer’s recommendation is 2 years;
it is too costly to calibrate every year. IEC recommends either to work with a
1-year interval or to follow the manufacturer’s recommendation (see Figures 2
and 3). The consensus is that a calibration interval of more than 2 years
involves a significant risk. Most utility-scale PV power plants employ
multiple pyranometers. They may send 50 % away for calibration in year one,
and the other 50 % in year two.
What level of accuracy?
IEC 61724-1 requires uncertainties of calibration; and expanded measurement
uncertainties with a coverage factor k of 2.
- Class A: 2 %
- Class B: 3 %
Why not on-site?
Pyranometer calibration equipment is costly, bulky and vulnerable; not easy to
transport.
Also, the on-site availability of the natural sun is not sufficiently reliable
to use for calibration. Even if the sun shines, it may not be sufficiently
stable, or at angles that are too close to the horizon.
In practice, outdoor pyranometer calibration will not attain the 2 %
uncertainty level required for Class A PV system performance measurement. In
some cases, the 3 % requirement of Class B systems will be attained, but this
is generally considered insufficient for utility-scale PV power plants. High-
accuracy solar calibrations are nowadays done at specialised laboratories.
More details on why you must send instruments to a laboratory.
Hukseflux
We are a leading manufacturer, both in technology and market share, of solar radiation sensors. We calibrate pyranometers of all commonly used brands. We can work more efficiently if you supply us with your sensors in batches of 3 or more instruments. You may then benefit from our quantity discounts.
Most popular pyranometer calibration services
Why work with us
- well-established and traceable calibration methods
- fast turnaround times
- quantity discounts
- calibration references for the most common brands and models
- Hukseflux has calibration facilities in the main global economies: USA, EU, China, India, Japan, Singapore, Australia and Brazil
- added service at added cost: temporary replacement instruments available
More about the compliance of pyranometers with the new IEC classification
Hukseflux is specialised in solar radiation measurement. A separate memo
offers comments on the consequences of the new standard concerning the
selection of pyranometers.
Where can I order the IEC standard?
The standard can be purchased from the IEC webshop.
About Hukseflux
Hukseflux is the leading expert in the measurement of energy transfer. We design and manufacture sensors and measuring systems that support the energy transition. We are market leaders in solar radiation and heat flux measurement. Customers are served through our headquarters in the Netherlands, and locally owned representative sales offices in the USA, Brazil, India, China, Southeast Asia and Japan.
Would you like more information? E-mail us at: info@hukseflux.com.
CONTACT
Copyright by Hukseflux. Version 2403. We reserve the right to change specifications without prior notice. For Hukseflux Thermal Sensors go to www.hukseflux.com or e-mail us: info@hukseflux.com.
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