Anton Driesse

Photovoltaic Performance Labs

Global irradiance sensors supply essential information in the business of planning and operating PV Systems. Errors and uncertainty in irradiance measurements propagate to uncertainty about performance and profitability. PV Performance Labs initiated the PVSENSOR project in 2014 to more fully characterize commercial irradiance sensors, with the obj...

(Click on the DOI link to get the full text.) Reference cells are widely used in the photovoltaic (PV) industry to measure irradiance. For field applications and outdoor use, a variety of products are on the market, and they are often perceived as a low-cost alternative to thermopile radiometers. But reference cell characteristics differ substanti...

Reference cells are widely used in the photovoltaic (PV) industry to measure irradiance. For field applications and outdoor use a variety of products are on the market and they are often perceived as low-cost alternatives to thermopile pyranometers. But reference cell characteristics, such as directional and spectral response, fundamentally differ...

PV module operating temperature is the second-most important factor influencing PV system yield—after irradiance—and a substantial contributor to uncertainty in energy system yield predictions. Models commonly used to predict operating temperature in system simulations are based on a simplified energy balance that lumps together different heat loss...

The Photovoltaic (PV) Performance Modeling Collaborative (PVPMC) organized a blind PV performance modeling intercomparison to allow PV modelers to blindly test their models and modeling ability against real system data. Measured weather and irradiance data were provided along with detailed descriptions of PV systems from two locations (Albuquerque,...

Backside irradiance comes from different directions. Structures have a 3D effect blocking the reflected irradiance. Conditions change from one point to another over the PV generator. Different mounting solutions are available. In the case of trackers, the conditions change over time because of sun movement due to tracker movement.

Irradiance transposition models seem to perform well, except the Isotropic with -11.25 W/m² underestimation. Most temperature models could not capture behavior when ΔΤ between module and ambient is negative. Uncertainties due to derate factors: modelers overbudgeted resulting in significant power underestimation; maybe ~10% is appropriate for comme...

PV module operating temperature is the second most important factor influencing system yield, after irradiance. A variety of temperature models are used within yield simulation software to predict module operating temperature, which then determines operating efficiency. Four temperature models are frequently used: PVsyst, Faiman, SAPM and SAM NOCT....

p>The IEC 61853 standard series aims to provide a standardized measure for PV module energy rating, namely the Climate Specific Energy Rating (CSER). For this purpose, it defines procedures for the experimental determination of input data and algorithms for calculating the CSER. However, some steps leave room for interpretation regarding the specif...

p>The IEC 61853 standard series aims to provide a standardized measure for PV module energy rating, namely the Climate Specific Energy Rating (CSER). For this purpose, it defines procedures for the experimental determination of input data and algorithms for calculating the CSER. However, some steps leave room for interpretation regarding the specif...

The IEC 61853 standard series aims to provide a standardized measure for photovoltaic (PV) module energy rating, namely the Climate Specific Energy Rating (CSER). For this purpose, it defines procedures for the experimental determination of input data and algorithms for calculating the CSER. However, some steps leave room for interpretation regardi...

(NREL) is a world-leading solar calibration and measurement facility and maintains and disseminates the World Radiation Reference (essentially the W/m2) for the United States, which is essential for traceable and accurate measurements of solar radiation at all solar generation facilities. SRRL operates two International Organization for Standardiza...

For all measurements, a provision of uncertainty for each measurement point is good practice. So far, a comprehensive methodology for uncertainties for Rotating Shadowband Irradiometers (RSI) has not been established, as the typical methods for calculating uncertainty are oversimplified, too time‐consuming, or both when instrument exhibits signific...

The installation of solar photovoltaic (PV) modules on carports or canopies combines power generation and shaded parking for vehicles in the case of carports, or power generation and shelter and shade for people, animals or goods without significant waste of land. Bifacial technology opens the door to various improvements and even new kinds of solu...

Agrivoltaics is a novel application of solar (PV) photovoltaic power generation where the PV modules are installed in the same field as to where the crops are also cultivated, combining land use. This study is focused on an installation with rows of vertical PV bifacial modules, blurring the classical separation between front and back side and requ...

Several simulation tools have appeared on the market to estimate the bifacial energy gain (BEG) of bifacial photovoltaic (PV) systems. These tools use two main families of methods that provide a quick estimation of the BEG or a detailed analysis of it, but not both. The current study presents an alternative methodology that provides both benefits u...

The installation of solar photovoltaic (PV) modules on carports or canopies is a relatively popular application of PV power generation. This advantageously combines power generation and shaded parking for vehicles in the case of carports, or power generation and shelter and shade for people, animals or goods with little waste of land. In parallel,...

Agrivoltaics is a novel application of solar (PV) photovoltaic power generation where the PV modules are installed in the same field as where crops are also cultivated. This is advantageous because this combines land use while keeping attractive productions for both agricultural crops and power generation. Several configurations currently exist for...

Several simulation tools have appeared on the market to estimate the bifacial energy gain (BEG) of bifacial photovoltaic (PV) systems. These tools use two main families of methods that provide a quick estimation of the BEG or a detailed analysis of it, but not both. The current study presents an alternative methodology that provides both benefits u...

The IEC 61853 photovoltaic (PV) module energy rating standard requires measuring module power (and hence, efficiency) over a matrix of irradiance and temperature conditions. These matrix points represent nearly the full range of operating conditions encountered in the field in all but the most extreme locations and create an opportunity to develop...

The IEC 61853 standard series "Photovoltaic (PV) module performance testing and energy rating" aims to provide a standardized measure for PV module performance, namely the Climate Specific Energy Rating (CSER). An algorithm to calculate CSER is specified in part 3 based on laboratory measurements defined in parts 1 and 2 as well as the climate data...

Accurate measurements of direct normal, diffuse horizontal and global horizontal irradiance (DNI, DHI and GHI) are needed for meteorological studies and are essential for the solar resource assessment at potential solar power plant sites. Often, these potential sites are remote and hence require robust sensors that require minimal maintenance that...

The IEC 61853 PV module energy rating standard requires measuring module power (and hence efficiency) over a matrix of irradiance and temperature conditions. These matrix points represent nearly the full range of operating conditions encountered in the field in all but the most extreme locations, and create an opportunity to develop alternative app...

Simulation software plays a critical role for planning, optimizing and evaluating PV systems—and for gaining investor confidence. Does it matter which software is used? Most, if not all, core calculations are based on the same published models (some of them very old), and most software documentation is open about the models and methods that are imp...

PV Performance Labs and Sandia Labs are working to promote the availability of IEC 61853 matrix measurements for commercial modules, and to develop and demonstrate methods for their use in PV system simulations. Please help us by sharing your data!

Accurate measurements of direct normal, diffuse horizontal and global horizontal irradiance (DNI, DHI and GHI) are needed for meteorological studies and are essential for the solar resource assessment at potential solar power plant sites. Often, these potential sites are remote and hence require robust sensors that require minimal maintenance that...

Quantifying and predicting electricity production from photovoltaic (PV) systems is based on measured or modeled irradiance data. These solar resource data consist of global horizontal irradiance, global tilted irradiance, direct normal irradiance, and diffuse horizontal irradiance, which are either derived from satellite observations validated aga...

Quantifying and predicting electricity production from photovoltaic (PV) systems is based on measured or modeled irradiance data. These solar resource data consist of global horizontal irradiance, global tilted irradiance, direct normal irradiance, and diffuse horizontal irradiance, which are either derived from satellite observations validated aga...

This study evaluates the response times of three types of ISO 9060 First Class pyrheliometers in the laboratory, and more generally, investigates the stabilization of their output signals in response to step changes in irradiance. Observations are similar to, but much more detailed than our previous testing of pyranometers. The link between respons...

Reference solar irradiance spectra are needed to specify key parameters of solar technologies such as photovoltaic cell efficiency, in a comparable way. The IEC 60904-3 and ASTM G173 standards present such spectra for Direct Normal Irradiance (DNI) and Global Tilted Irradiance (GTI) on a 37° tilted sun-facing surface for one set of clear-sky condit...

This paper introduces a concept for global tilted irradiance (GTI) subordinate standard spectra to supplement the current standard spectra used in solar photovoltaic applications, as defined in ASTM G173 and IEC60904. The proposed subordinate standard spectra correspond to atmospheric conditions and tilt angles that depart significantly from the ma...

As part of the PVSENSOR project, we have analyzed the measurement errors in one-minute average values of tilted irradiance for 21 sensor types installed two locations. We report here on the observed directional errors, and on the range and distribution of the errors. We also show how the distribution of the errors changes when the directional error...

We have measured and analyzed the response of 10 photodiode pyranometers and 12 reference cells under clear sky conditions and small incidence angles. After directional, spectral, and temperature corrections we calculated their apparent responsivity factors in relation to a high-quality reference cell. Here, we present how these outdoor responsivit...

Irradiance sensors supply essential information in the business of planning and operating PV Systems. Errors and uncertainty in irradiance measurements propagate to uncertainty about performance and profitability. PV Performance Labs initiated the PVSENSOR project in 2014 to more fully characterize commercial irradiance sensors, with the objective...

Global irradiance sensors supply essential information in the business of planning and operating PV Systems. Errors and uncertainty in irradiance measurements propagate to uncertainty about performance and profitability. PV Performance Labs initiated the PVSENSOR project in 2014 to more fully characterize commercial irradiance sensors, with the obj...

Accurate photovoltaic system performance monitoring is critical for profitable long-term operation. Irradiance, temperature, power, current and voltage signals contain rapid fluctuations that are not observable by typical monitoring systems. Nevertheless these fluctuations can affect the accuracy of the data that are stored. We closely examine el...

The performance of photovoltaic systems must be monitored accurately to ensure profitable long-term operation. The most important signals to be measured—irradiance and temperature, as well as power, current and voltage on both DC and AC sides of the system—contain rapid fluctuations that are not observable by typical monitoring systems. Nevertheles...

Wichtigste Eingangsgröße von Ertragsgutachten für Photovoltaikanlagen ist die prognostizierte mittlere Globalstrahlung am Standort. Die Globalstrahlung auf der Erdoberfläche unterliegt allerdings langfristigen Veränderungen, einem Phänomen, bekannt unter dem Namen „Global dimming and brightening“ [1]. Nach einem Rückgang der Globalstrahlung seit de...

Solar resource assessments use solar radiation data from past observations to estimate the average annual solar radiation over the expected lifetime for a solar energy system. However, solar radiation at the Earth’s surface is not stable over time but undergoes significant long-term variations often referred to as “global dimming and brightening”....

Ertragsgutachten für PV-Anlagen vor dem Hintergrund von Global Dimming and Brightening

Today’s PV systems tend to get larger, so even small improvements in Performance Ratio (PR) may lead to remarkable financial benefits. The PR depends on several design decisions, and in most cases, the advantage of a design decision may be confirmed in advance by simulation only. To validate system simulation models for this purpose, we compare hig...

The main purpose of PV system performance monitoring is to determine whether the system is operating as expected. This requires measuring the actual output of the system as well as the conditions under which it is operating. Solar radiation intensity in the plane of the array (POA) is by far the most important operating condition and is the basis f...

As the solar industry matures, custom designed projects are giving way to standardized installation practices that expose PV arrays to a variety of non-ideal conditions. In the search for solutions, lower module prices are shifting the attention to system integration components and techniques. While the susceptibility of conventional system design...

This report summarizes the uncertainties associated with the prediction of long-term photovoltaic (PV) yield. The report addresses mainly uncertainties facing large-scale PV developers, although some of the conclusions may also be applicable to small systems. The uncertainties facing developers include factors such as expected yield, government po...

Mismatch losses due to non-uniform conditions such as partial shading are the focus of much attention. New products aimed at reducing those losses in long series strings introduce system complexities while promising substantial performance gains. A simpler strategy to combat mismatch losses is to reduce the number of modules in series, and increase...

The simulation of photovoltaic (PV) power systems relies on appropriate models of the PV array, power conversion electronics, operating conditions and sometimes, energy storage and loads. This paper presents a model of intermediate complexity for grid-tie inverters that can capture many differences between specific products, yet remains generic eno...

It has been noted that the models typically used to represent inverters in simulation and design tools at the present are inadequate because they do not capture the variations in electrical efficiency over the full range of operating conditions. Data to develop more detailed models have been scarce in the past, but are now increasingly available fr...

Maximum Power Point Tracking methods control the operating voltage of photovoltaic arrays in order to maximize their power output. This paper presents a method to evaluate the effectiveness of such methods continuously in operating photovoltaic power systems, and hence, under real-world conditions. When operating, the maximum power cannot be measur...

The 20-kW photovoltaic array on the facade of Goodwin Hall, Queen's University has been operating nearly continuously since July 2003 and its performance and operating conditions have been recorded in detail since that time. Analysis of the data revealed some shortcomings in the measurement process but also gave insight into different aspects of sy...

The 20-kW photovoltaic array on the facade of Goodwin Hall, Queen's University has been operating nearly continuously since July 2003 and its performance and operating conditions have been recorded in detail since that time. Analysis of the data revealed some shortcomings in the measurement process but also gave insight into different aspects of sy...

Photovoltaic cells convert energy from sunlight directly into electricity without moving parts or chemical reactions. The technology of photovoltaic cells and of the components that make up photovoltaic systems continues to evolve and mature, but it is already the technology of choice to provide electricity in many situations. This article provides...

A 20 kW grid-connected PV array, one of the larger systems in Canada, was installed on the Queen's University campus in Kingston during the first half of 2003. Planning for the array began more than 18 months earlier with the identification of an appropriate façade having good exposure to both solar radiation and passers-by. From its inception, the...

A 20 kW grid-connected PV array, one of the larger systems in Canada, was installed on the Queen's University campus in Kingston during the first quarter of 2003. Planning for the array began more than 18 months earlier with the identification of an appropriate façade. The initial design consisted of 330 panels mounted as awnings above the windows...

In this paper we investigate a new relationship between duration of sunshine and solar radiation on the earth’s surface that was derived recently by Suehrcke (Solar Energy, 68(5) (2000) 417). We test the relationship using over 70,000 measured monthly sunshine and radiation data from nearly 700 sites compiled by the World Radiation Data Center. We...

This paper presents a tempo tracking system adaptable to different styles of music. The system analyzes tonal music having a rhythmic structure based on a simple meter. The focus is on tracking gradual tempo changes during the live performance of a piece of music. A musician using the system plays an instrument connected to the computer through a...