Jan Remund

• dipl. Natw. ETH
• Head of Department at Meteotest

This fourth edition of the Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications has been prepared under the leadership of the National Renewable Energy Laboratory (NREL) together with a team of worldwide experts that consists of 51 authors from 11 countries working within the framework of the Inter...

The “Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications” provides best practices for obtaining and applying solar resource data across a range of solar technologies, including photovoltaics (PV), solar heating and cooling, and concentrating solar power (CSP). A particular focus is placed on the i...

A firm photovoltaic (PV) plant differs from a conventional unconstrained PV plant in terms of its ability to satisfy load demand on a 24/365 basis. Amongst various firm power enablers, overbuilding & proactive curtailment is the most counter-intuitive yet indispensable one. Although the cost-effectiveness of firm PV plants has been studied numerous...

In several countries, PV capacity has exceeded the country's minimum load. Unlimited feed-in at all times is therefore becoming less and less possible. Curtailment is not a goal. It is a method for increasing the utilization of power grids without exceeding their physical limits. The ratio of annual energy yield to peak power is smaller for PV sy...

Die variable, erneuerbare Stromerzeugung ist in den letzten Jahrzehnten als Ergänzung von abschaltbarer und grundlastfähiger konventioneller Erzeugung stark gewachsen. Mit zunehmender Durchdringung dieser variablen Ressourcen wird das Management der Residuallast immer komplexer und kostspieliger. Die Herausforderung für die netzgekoppelte Solarener...

Grid‐connected photovoltaic (PV) electricity production is steadily growing at the margin of conventional power generation, but its management is becoming more complex. To overcome this challenge, we propose a transformation of variable renewable energy (VRE) resources into firm power generation. Drawing on insights from IEA PVPS Task 16 case studi...

Norway spruce is one of the most important tree species in Central Europe, however, it is facing major problems with recent droughts. In this study we present 37 years (1985-2022) of long-term forest observation data on 82 different forest sites across Switzerland including 134'348 tree observations. The sites consists of managed spruce or mixed fo...

Mit der Energiekrise im Sommer 2022 schärfte sich das Bewusstsein für kommende mögliche Energiemangellagen insbesondere im Winter. Die schnellste Art die Winterstromproduktion in der Schweiz zu erhöhen ist der Bau von alpinen PV-Anlagen. Die Diskussion nahm im Sommer 2022 rasch Fahrt auf und führte zu einem neuen Gesetz [2], welches solche Anlagen...

In this fourth part, guidance for the selection, deployment and mainte-nance of meteorological sensors, power measurements and associated data quality control relevant to real-time forecasting is provided. The full version is available online as OpenAccess here: https://www.sciencedirect.com/book/9780443186813/iea-wind-recommended-practice-for-...

Fluctuations of the incoming solar irradiance impact the power generation from photovoltaic and concentrating solar thermal power plants. Accurate solar nowcasting becomes necessary to detect these sudden changes of generated power and to provide the desired information for optimal exploitation of solar systems. In the framework of the Internationa...

In this paper we compare a state-of-the-art cloud-motion tracking solution against a data-driven solution for photovoltaic (PV) power production to provide insights into their performance drivers. The solutions are MeteoTest's CloudMove, based on cloud-motion tracking from satellite images, and CSEM's data-driven solution based on graph machine lea...

Fourth Edition of the Handbook: Planned Timeline • To help stakeholders stay aware of the latest research in solar resource data, the National Renewable Energy Laboratory (NREL), in collaboration with the International Energy Agency (IEA) Photovoltaic Power Systems Programme (PVPS) Task 16 and the Solar Power and Chemical Energy Systems (SolarPACES...

Solar forecasting constitutes a critical tool for operating, producing and storing generated power from solar farms. In the framework of the International Energy Agency’s Photovoltaic Power Systems Program Task 16, the solar irradiance nowcast algorithms, based on five all-sky imagers (ASIs), are used to investigate the feasibility of ASIs to fores...

We investigate whether photovoltaics (PV) can effectively and economically contribute to a massively renewable energy (RE) power generation future for Switzerland. Taking advantage of the country’s flex-ible hydropower resources, we determine the optimum PV/battery configurations that can meet the country’s growing electrical demand firmly 24x365 a...

The Climate-fit.City service ( https://www.climate-fit.city ) provides the best available scientific urban climate data and information for public and private end users operating in cities. Within the Climate-fit.City H2020 project, the benefits of urban climate information for end user communities was demonstrated, considering services in diverse...

European beech is one of the most important deciduous tree species in natural forest ecosystems in Central Europe. Its dominance is now being questioned by the emerging drought damages due to the increased incidence of severe summer droughts. In Switzerland, Fagus sylvatica have been observed in the Intercantonal Forest Observation Program since 19...

Die Photovoltaik entwickelt sich zu einer tragenden Säule der Strom­versorgung. Es lohnt sich deshalb, die Wetter­einflüsse auf den PV-Ertrag zu untersuchen, um Business­pläne zu verfeinern oder die Vernetzung mit anderen Energie­trägern zu optimieren. Langjährige Betriebsdaten des Sonnen­kraftwerks Mont-Soleil wurden dazu mit Meteodaten korreliert...

Sunlight is the fuel for all solar energy generation technologies. For any generation source and its users , knowledge of the quality and future reliability of the fuel is essential for accurate control and analysis of system performance and to determine the financial viability of projects. Information about the resources and forecasts are conclude...

Four solar cycles show the temporal variations of daily TSI in a composite reconstruction of the 1976-2017 time series based on observations from spaceborne radiometers after corrections and gap-filling. The thick line indicates the 27-day moving average (corresponding to the 27-day mean solar rotation period), and the circled numbers refer to the...

Recent advances in Computer Vision and Deep Learning have enabled astonishing results in a variety of fields and applications. Motivated by this success, the SkyCam Dataset aims to enable image-based Deep Learning solutions for short-term, precise prediction of solar radiation on a local level. For the span of a year, three different cameras in thr...

This third edition of the handbook follows only less than four years after the previous edition, published in 2017, and marks the rapid evolution in the field of solar resource assessment and forecasting. It reflects the considerable progress that has occurred since then in the measurement and modeling of solar radiation and related topics. For ins...

The understanding of intra-urban air temperature variations is crucial to assess strategies for cities' adaptation to impacts of present and future anthropogenic climate change. Depending on extensive measurement networks, high-resolution air temperature measurements in urban environments are challenging due to high instrumentation and maintenance...

In this report, we compare the accuracy of several up-scaling methods for regional PV power forecast from 1 up to 3 days-ahead using three different case studies characterized by different sizes of the area of interest and located in two different countries (Netherlands and Italy)

High-accuracy solar radiation data are needed in almost every solar energy project for bankability. Time series of solar irradiance components that spans decades can be supplied by satellite-derived irradiance or by reanalysis models, with very various types of uncertainty associated to the specific approaches taken and quality of boundary conditio...

Der Vortrag zeigt den Stand der Arbeiten im IEA PVPS Task 16 (2017-2023) anhand von ausgewählten activities. Beispielswiese werden die Trend der Globalstrahlung in der Schweiz oder einen Vergleich von Solarkatastern in der Schweiz kurz beleuchtet.

Climate change and the urban heat effect are expected to have a large influence on the energy consumption and thermal comfort of buildings. However, using meteorological data which incorporates effects of climate change and characteristics of cities is not currently a standard practice in building simulation. By default, data of nearby meteorologic...

Photovoltaic power has the temporal and spatial variability associated with the natural intermittency of solar resource. This variability results in potential threats to the grid since it must be able to accommodate safely the foreseeing variability. This chapter gives an overview of the variability scales and its quantification. The smoothing effe...

A new joint Task of IEA Technological Collaboration Programmes PVPS and SolarPACES started in July 2017 and will last till 2020. 21 countries and 54 partners are part of the Task. Many existing partners of IEA SHC Task 46 like NREL or Mines Paristech are part but also new partners-like the Swedish met service SMHI or Energinet (TSO of Denmark). In...

Global irradiation is the main source for photovoltaic (PV) energy production. The knowledge of the incoming solar shortwave irradiation is of major importance for the planning, monitoring and operation of solar energy power plants and grid operations. In this paper we present a validation of the newly developed Meteonorm Satellite Irradiation (MNS...

Climate change and the urban heat effect is expected to have a large influence on the energy consumption and thermal comfort of buildings. However, using meteorological data which incorporates effects of climate change and characteristics of cities is not currently a standard practice in building simulation. By default, Typical Meteorological Years...

The IEA Task 16 has been approved at the ExCo meeting in November 2016 in Vienna. The official start of the Task was July 2017. It will go on for three years till June 2020. Task 16 is a joint Task with the TCP SolarPACES (Task V). The Task has been approved by the SolarPACES ExCo in October 2016. It will keep also minimal collaboration with the SH...

The aim of this chapter is to describe the use of satellite-derived surface solar irradiance (SSI) from the continuous optical image acquisition of geostationary meteorological satellites to produce solar power forecasting, typically for intraday time horizons from 0 to 6. h ahead. Different approaches and products of satellite-based SSI retrieval...

A new joint Task of IEA Technological Collaboration Programmes PVPS (Photovoltaic Power Systems Program) and SolarPACES (Solar Power And Chemical Energy Systems) has started in July 2017 and lasts for three years. The PVPS Task 16 will be led by Jan This paper shows the main topics of the work plan. The main goal is to lower uncertainty of resource...

Irradiation data can be confusing at first glance: depending on the source and time period, these vary considerably. On the one hand, this is linked to the data source (soil measurements or satellite data) and on the other hand to climate variability. In the Swiss Plateau the radiation has increased significantly for 30 years. PV plants deliver 10%...

Die Potenziale der Solarwärme und des Solarstroms wurden auf Basis der neusten Datengrundlagen neu berechnet. Diese haben sich seit der letzten gesamtschweizerischen Schätzung des BAFU (2012) stark verbessert – dies v.a. auf Grund des nationalen Solardachkatasters (www.sonnendach.ch). Die Solarpotenzialschätzungen von 2017 liegen deutlich höher als...

Advancing renewable energy technologies will require improvements to our understanding of solar radiation resources. This chapter briefly describes the areas of research and development identified as emerging technology needs. The International Energy Agency (IEA) Photovoltaic Power System (PVPS) Task 16 work plan on “solar resource for high penetr...

Weltweit und in der Schweiz ist der Klimawandel seit der Industrialisierung gut doku- mentiert. Die Temperaturen sind hierzulande seit 1864 um rund 1,8 °C gestiegen, beim Niederschlag ist kein genereller Trend sichtbar. Für die Zukunft bis 2100 modellierten wir Klimadaten basierend auf dem Emissionsszenario A1B und drei verschiedenen re- gionalen...

Le changement climatique que la planète enregistre depuis le début de l’ère industrielle a été largement décrit, tant à l’échelle mondiale qu’en Suisse. Dans notre pays, les tem- pératures ont augmenté de 1,8 °C environ depuis 1864, alors que les précipitations n’ont pas dénoté de tendance générale. En nous fondant sur le scénario d’émission A1B...

Radiation data in one minute time resolution is getting more important nowadays. Especially for modelling self-consumption and batteries it’s needed and for mid or large PV plants it reduces modelling uncertainties. Up to now different models have been published and used - also in Meteonorm 7. Most of them didn’t show convincing quality. Therefore...

Der Ersatz von Strom aus den Kernkraftwerken durch Strom aus erneuerbaren Energien ist ein Thema, das heute sowohl Energieproduzenten, Netzbetreiber wie auch Stromverbraucher beschäftigt. Für die Stromgewin- nung hat die Photovoltaik (PV) von allen erneuerbaren Energien das grösste Potenzial. Da aber Solarstrom unregelmässig anfällt, stellt si...

At any site, the bankability of a projected solar power plant largely depends on the accuracy and general quality of the solar radiation data generated during the solar resource assessment phase. The term “site adaptation” has recently started to be used in the framework of solar energy projects to refer to the improvement that can be achieved in s...

At any site, the bankability of a projected solar power plant largely depends on the accuracy and general quality of the solar radiation data generated during the solar resource assessment phase. The term "site adaptation" has recently started to be used in the framework of solar energy projects to refer to the improvement that can be achieved in s...

In the framework of the IEA SHC Task 46 “Solar Resource Assessment and Forecasting” we compare solar global horizontal irradiance forecasts based on numerical weather predictions for a variety of different models. These include direct model output of several numerical weather prediction models, a rapid update cycle model assimilating satellite deri...

Accurate knowledge of the future state of direct normal irradiance (DNI) is needed for the successful operation of concentrated solar technologies like concentrating solar power (CSP) or concentrating photovoltaics (CPV). For different applications within a power plant forecast horizons of 0 to 4 hours with spatial resolutions from meters to kilome...

Due to the strong growth in photovoltaics (PVs), forecasting is gaining importance. At present, most forecasts are based on numerical weather prediction (NWP) models without cloud assimilation. These models lack the ability to forecast the exact position of clouds, which is needed for single-point forecasts. Nowcasting methods, based on current inf...

The increasing penetration of PV systems in the distribution network creates new opportunities but also raises several issues for the grid operation. New challenges, arising from the variable nature of solar energy generation, must be tackled in order to keep a stable and balanced power grid. In this study, short term variability in power output d...

State and development of drought in Swiss forests Climate scenarios for the 21st century for Switzerland show increasing temperatures and more frequent weather extremes and the risk of drought will become more important. The objective of the study was the calculation of indicators which allow the estimation and evaluation of drought risks on a regi...

Indicators for quantitative assessment of drought risks in beech and Norway spruce forests The application of climate models to forecast future forest development asks for quantitative drought-response relationships, with the term “drought” first needing a definition. The long-term data series of an intercantonal forest observation program allowed...

Finanzielle aspekte und Fragen der Stromspeicherung Der Ersatz von Strom aus den Kernkraftwerken durch Strom aus erneuerbaren Energien soll in den nächsten Jahrzehnten erfolgen. Dabei stellen sich hauptsächlich zwei Fragen: Wie soll die Speicherung der unregelmässig anfallenden erneuerbaren Beiträge erfolgen? Und was sind die finanziellen Belastung...

In a first phase, until 2023, around 9 TWh/year, of nuclear current will have to be replaced by other sources. Authors suggest as replacement 5.2 TWh/year from Photovoltaics, and the remainder mainly from other renewable sources. Consequences of this strategy on Current Storage Requirements and on FIT costs will be detailed.

Zusammenfassung Aufgrund von langjährigen Waldbeobachtungsdaten aus der Schweiz wurden ver-schiedene Trockenheitsindizes berechnet, verglichen und für eine quantitative Anwendung in Klimaszenarien evaluiert. Der Grundflächenzuwachs konnte am besten mit Indikatoren der Standortswasserbilanz erklärt werden, ebenso die Buchenmortalität, während für di...

In this paper we present the CloudMove forecast system for shortest term solar radiation forecasting for entire Europe for the next six hours. The system is based on satellite images from Meteosat Second Generation and numerical weather prediction model for wind field predictions. The clearness index is determined for each pixel. This cloud pattern...

During the past four years, national experts from 11 institutions around the world have worked together within Subtask 3 – High penetration solutions for central PV generation scenarios – in order to identify best practice scenarios for a technically and economically improved grid integration of PV focusing on aspects at a power system level. The s...

The field of solar and photovoltaic (PV) forecasting is rapidly evolving. The current report provides a snapshot of the state of the art of this dynamic research area, focusing on solar and PV forecasts for time horizons ranging from a few minutes ahead to several days ahead. Diverse resources are used to generate solar and PV forecasts, ranging fr...

The paper presents the main goals and achievements of the Smart Grids ERA-NET project named “Efficient identification of opportunities for Distributed Generation based on Smart Grid Technology (SmartGen)” during the second stage of project implementation. A description of Smart Grid Technology (SGT) models developed within the framework of the proj...

A solar cadastre provides a perfect data source for a small scale analysis of the solar potential. Based on the data from the solar cadastre grid simulations for parts of the distribution grid were performed. The results of the grid simulations show that the voltage increase becomes critical in most cases. However, taking into account reactive powe...

This article combines and discusses three independent validations of global horizontal irradiance (GHI) multi-day forecast models that were conducted in the US, Canada and Europe. All forecast models are based directly or indirectly on numerical weather prediction (NWP). Two models are common to the three validation efforts - the ECMWF global model...

Wir präsentieren hier Ergebnisse aus einem gemeinsamen Projekt von Meteotest mit dem städtischen Energieversorger energie wasser bern (ewb). Mit Hilfe der PV-Leistung aus einem Solarkataster und den verfügbaren Netz-und Verbrauchsdaten konnten detaillierte Netzsimulationen durchgeführt werden. Die Netzsimulationen zeigen, dass PV-Einspeisung in gro...

In diesem Bericht wird untersucht, wie sich die Variabilität des deutschen Strombedarfs in Abhängigkeit von der installierten Leistung der Photovoltaik (PV) verändert. Die Untersuchung zeigt, dass die Variabilität der Stromnachfrage im Moment einen absoluten Tiefpunkt durchläuft. Dies deshalb, weil die momentan in Deutschland installierte PV-Leistu...

Ein Szenario, das den Atomstrom zu 70% durch Solarenergie ersetzt, ist realistisch und möglich, ohne die Versorgungssicherheit im Winter zu gefährden, sofern die übrigen 30% durch Windkraft und Biomasse gedeckt werden. Der zusätzliche Speicherbedarf für das Winterhalbjahr bleibt moderat, da sich die Sonnenenergie und die Produktion der Laufwasserkr...

Ein Szenario, das den Atomstrom zu 70% durch Solarenergie ersetzt, ist realistisch und möglich, ohne die Versorgungssicherheit im Winter zu gefährden, sofern die übrigen 30% durch Windkraft und Biomasse gedeckt werden. Der zusätzliche Speicherbedarf für das Winterhalbjahr bleibt moderat, da sich die Sonnenenergie und die Produktion der Laufwasserkr...

Forecast of solar radiation gets more and more important. For regions with more than 1 – 2% of the electricity produced by PV the regional forecasts are needed for the grid integration. At the moment different forecast models are available and the market grows fast. In order to give an overview of the models and give some level of uncertainties a q...

Forecast of solar radiation gets more and more important. For regions with more than 1 – 2% of the electricity produced by PV the regional forecasts are needed for the grid integration. At the moment different forecast models are available and the market grows fast. In order to give an overview of the models and give some level of uncertainties a q...

The high growth rate of photovoltaic (PV) installations leads to the question about the consequences for grid integration and management. As a case study, we present an analysis of the first limits for the amount of PV electricity in the utility grid of the greater Zurich area. The first limit is found at an amount of 6% of the yearly electricity g...

Knowledge of the solar energy resource is essential for the planning and operation of solar energy systems. In past years there has been substantial European and national funding to develop information systems on solar radiation data, leading to the situations that several data bases exist in parallel, developed by different approaches, various spa...

With growing installations of solar power plants and integration into the electricity grid there is a demand for forecasting the energy production on a short-term basis for the entire electricity management. Within IEA SHC Task 36, which ran from mid 2005 until mid 2011, METEOTEST made tests in the Alpine region with its operational numerical weath...

The global climatological database Meteonorm (www.meteonorm.com) is widely used as meteorological input for simulation of solar applications and buildings. It's a combination of a climate database, a spatial interpolation tool and a stochastic weather generator. Like this typical years with hourly or minute time resolution can be calculated for any...

The knowledge of the means, variations and trends of global radiation is important for planning solar applications. This analysis is focused on long time series of global radiation with a duration of at least 40 years within the period 1950 - 2009. Like this work lies in-between the analysis for worldwide (satellite) data with approx. 20 years of d...

This analysis is focused on long time series of global radiation with a duration of at least 40 years within the period 1950 - 2009. Like this work lies in-between the analysis for worldwide (satellite) data with approx. 20 years of duration and those for some few sites with very long measurements. A total of 24 sites based on Global Energy Balance...

Knowledge of the solar resource is essential for the planning and operation of solar energy systems. A number of data bases giving information on solar resources have been developed over the past years. The result is a fragmentation of services each having each own mechanism of access and all are giving different results due to different methods, i...