Wilfried van Sark

Wilfried van Sark
Utrecht University | UU · Copernicus Institute of Sustainable Development

Ph.D.

About

435
Publications
170,815
Reads
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11,125
Citations
Citations since 2016
165 Research Items
7197 Citations
201620172018201920202021202202004006008001,0001,2001,400
201620172018201920202021202202004006008001,0001,2001,400
201620172018201920202021202202004006008001,0001,2001,400
201620172018201920202021202202004006008001,0001,2001,400
Introduction
Prof.dr Wilfried van Sark has over 35 years experience in the field of Photovoltaics Solar Energy research and development. Started with solar cell characterization at AMOLF Amsterdam, his work entailed III-V solar cell and processing development, thin film silicon cell and processing development, and more recently basic spectral shifting processes for next generation photovoltaics (up and down conversion) applied to luminescent solar concentrators. Also, he is a recognized expert in performance analysis of photovoltaic modules and systems, and life cycle and market analysis. In addition, deployment of photovoltaics in residential areas has lead to research in building integrated photovoltaics, smart grids with electric mobility and vehicle-to-grid technology, as well as solar forecasting.
Additional affiliations
January 2014 - present
Utrecht University
Position
  • Professor (Associate)
November 2002 - December 2013
Utrecht University
Position
  • Professor (Assistant)
July 1999 - November 2002
Utrecht University
Position
  • Senior Researcher

Publications

Publications (435)
Article
In line with the Dutch Climate Agreement, multiple energy transition scenarios have been constructed for 2030 and 2050. To various extents, they project a shift towards decentralized and intermittent renewable electricity generation (wind and solar) and widespread deployment of electric vehicles and heat pumps. These developments impose challenges...
Conference Paper
Full-text available
Electric vehicles have significant potential to reduce their charging costs by participating in electricity markets through electric vehicle smart charging. However, one of the main barriers for electric vehicle participation in an electricity market is the high uncertainty in their availability at the market gate closure time. Not accounting for t...
Article
Electricity generation with photovoltaic (PV) solar energy technology requires significant amounts of space; a particular point of discussion in a densely populated country like the Netherlands. Therefore, we developed a new analytical framework to analyse potential electricity generation for specific PV typologies on 43 different land utilisation...
Article
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...
Article
Full-text available
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...
Article
In this study we introduce an open-source dataset holding power measurements of 175 residential photovoltaic (PV) systems that are distributed throughout the province of Utrecht, the Netherlands. The dataset features power measurements with a high temporal resolution, i.e. 1-min, for the period January 2014 until December 2017 (over 260 million dat...
Article
In photovoltaic power ratings, a single solar spectrum, AM1.5, is the de facto standard for record laboratory efficiencies, commercial module specifications, and performance ratios of solar power plants. More detailed energy analysis that accounts for local spectral irradiance, along with temperature and broadband irradiance, reduces forecast error...
Article
Full-text available
The luminescent solar concentrator (LSC) as energy harvesting window is an emerging technology in the realm of building integrated photovoltaics. Using recent advancement for assessing the balance between transmitted color quality and potential electricity generation, this paper optimizes theoretical luminophore absorption spectra for the highest p...
Article
Full-text available
In this paper, the effect of dynamic albedo on modelling energy generation of a floating offshore photovoltaic system is quantified, for a system assumed to be installed at the North Sea. The dynamic albedo is modeled as a function of solar irradiation, wind speed and solar zenith angle at an hourly time resolution. The energy output of a floating...
Article
Full-text available
Rapid integration of photovoltaic systems and electric vehicles in low-voltage grids increasingly causes grid congestion. To avoid costly grid reinforcements, distribution system operators are looking into applying electric vehicle smart charging algorithms to shift part of the load to off-peak hours. However, multiple barriers hamper the large-sca...
Article
Full-text available
Fluctuating electricity prices offer potential economic savings for the consumption of electricity by flexible assets such as Electric Vehicles (EVs). This study proposes an operational bidding framework that minimizes the charging costs of an EV fleet by submitting an optimized bid to the day-ahead electricity market. The framework consists of a b...
Article
Full-text available
Low-lying coastal areas and archipelago countries are particularly threatened by the impacts of climate change. Concurrently, many island states still rely on extensive use of imported fossil fuels, above all diesel for electricity generation, in addition to hydrocarbon-based fuels to supply aviation and marine transportation. Land area is usually...
Article
Fair and meaningful device performance comparison among luminescent solar concentrator-photovoltaic (LSC-PV) reports cannot be realized without a general consensus on reporting standards in LSC-PV research. Therefore, it is imperative to adopt standardized characterization protocols for these emerging types of PV devices that are consistent with ot...
Chapter
Accurate forecasts of the electric power generation by solar Photovoltaic (PV) systems are essential to support their vast increasing integration. This study evaluates the interdependence of 14 predictor variables and their importance to machine learning models that forecast the day-ahead PV power production. To this purpose, we use two feature sel...
Article
Hydrogen is deemed necessary for the realization of a sustainable society, especially when renewable energy is used to generate hydrogen. As most of the photon-driven hydrogen production methods are not commercially available yet, this study has investigated the techno-economic and overall performance of four different solar-to-hydrogen methods and...
Article
Full-text available
Transient clouds cause rapid changes in the power output of Photovoltaic (PV) solar systems. These ramp rates may lead to power quality problems, such as voltage fluctuations, in the low-voltage (LV) electricity grid. This paper firstly assesses the impact of a growing number of distributed PV systems on the voltage profile in a LV grid by consider...
Article
Full-text available
Accurate forecasts of the power production of distributed photovoltaic (PV) systems are essential to support grid operation and enable a high PV penetration rate in the electricity grid. In this study, we analyse the performance of 12 different models that forecast the day-ahead power production in agreement with market conditions. These models inc...
Article
Over the past years, a new technology has emerged in the solar photovoltaics market: building-integrated photovoltaics (BIPV). Even though this technology has a lot of potential, the diffusion of BIPV has remained rather limited, globally and also in the Netherlands. In this paper, the Technological Innovation System (TIS) approach is used to analy...
Article
This paper presents a classical estimation problem for calculating the energy generated by photovoltaic solar energy systems, on a daily, annual, regional and national basis. Our methodology relies on two data sources: PVOutput, an online portal with solar energy production measurements, and modelled irradiance data available for large parts of Afr...
Chapter
This article provides an overview of the various aspects of photovoltaic (PV) system components and design. The basic theory of PV cell, module, and inverter performance is described, including how this knowledge is applied in PV system design. Typical steps in PV system design and project development are discussed, and some examples of typical PV...
Preprint
In comparisons of solar photovoltaic performance, variation in the spectrum of sunlight is often neglected. A single spectrum, AM1.5, is used as the standard condition both for comparison of competing solar cell technologies and evaluation of energy generation from solar power plants. The addition of solar spectrum variation provides a more relevan...
Article
Outdoor music festivals and construction sites are relying on temporary power installations for electricity supply. Diesel generators are still the dominant source for these applications. Cost and diesel consumption data are gathered from different field applications, to simulate different configurations of diesel generators in parallel, based on h...
Article
Full-text available
In this paper we propose a low-cost method to capture and purify CO2 from ocean water indirectly from the atmosphere. Atmospheric CO2 dissolves in seawater following Henry’s law. In Open Cycle OTEC (OC-OTEC), being a heat engine, large quantities of water are used to generate electricity from temperature differences in the ocean. CO2 and other gase...
Article
Full-text available
Partial shading is widely considered to be a limiting factor in the performance of photovoltaic (PV) systems applied in urban environments. Modern system architectures combined with per module deployment of power electronics have been used to improve performance especially at heterogeneous irradiance conditions. In this work another approach is use...
Article
Full-text available
In many areas in the world, the high voltage (HV) electricity grid is saturated, which makes it difficult to accommodate additional solar photovoltaic (PV) systems connection requests. In this paper, different scenarios to increase the installed PV capacity in a saturated grid are assessed on the basis of the net present value (NPV). The developed...
Article
Full-text available
Geographic information system (GIS) based tools have become popular for solar photovoltaic (PV) potential estimations, especially in urban areas. There are readily available tools for the mapping and estimation of solar irradiation that give results with the click of a button. Although these tools capture the complexities of the urban environment,...
Article
Full-text available
The IEA PVPS Task 13 group, experts who focus on photovoltaic performance, operation, and reliability from several leading R&D centers, universities, and industrial companies, is developing a framework for the calculation of performance loss rates of a large number of commercial and research photovoltaic (PV) power plants and their related weather...
Article
Full-text available
In this paper, a techno-economic analysis is performed to assess the feasibility of adding an offshore floating solar farm to an existing Dutch offshore wind farm in the North Sea, under the constraint of a certain fixed cable capacity. The specific capacity of the cable that connects the offshore park to the onshore grid is not fully used due to t...
Article
Full-text available
Partial shading is widely considered to be a limiting factor in the performance of photovoltaic (PV) systems applied in urban environments. Modern system architectures, combined with per module deployment of power electronics, have been used to improve performance, especially at heterogeneous irradiance conditions, but they come with a high investm...
Chapter
A luminescent solar concentrator consists of a waveguide collector and solar cells connected to the waveguide sides or bottom. Luminescent centers, such as organic dye molecules and nanoparticles absorb incoming photons and emit red-shifted photons that are mostly trapped inside the waveguide due to total internal reflection and finally coupled out...
Chapter
The field of product-integrated photovoltaics (PIPV) covers all applications where products are powered by a photovoltaic generator mounted on the device. This article presents the current state of the art of PIPV and experiences for various product categories. Applications such as arts, business-to-business and consumer devices, Internet of Things...
Chapter
This article provides an overview of the various aspects of floating photovoltaic (FPV) system components and design, both for onshore and offshore applications. These include global growth, market, and potential. Special attention is given to experimental and modeled performance advantages as well as to the role of FPV systems in hybrid renewable...
Chapter
Power generation from solar and wind energy systems is highly variable due to its dependence on meteorological conditions. An efficient use of these fluctuating energy sources requires reliable forecast information for management and operation strategies. We give an overview of different applications and state-of-the-art models for solar photovolta...
Chapter
This chapter provides a concise overview of the developments in photovoltaic (PV) solar energy. It has taken nearly 60 years for the PV industry to develop into a 100 billion business, and it will another 10 of years to reach a trillion-dollar level, which is much needed for a transition to a society based on renewable energy sources. The complete...
Chapter
A variety of factors, including government activities, have enabled over three orders of magnitude reduction in the cost of photovoltaics (PV) over the past six decades. No single determinant predominantly explains the improvement to date; R&D, economies of scale, learning by doing, and knowledge spillovers from other technologies have all played a...
Technical Report
Full-text available
The photovoltaic (PV) energy rating is related to the energy yield performance of a PV module. Unlike the power rating, which is only related to the performance at a single operating point at 25°C, 1000 W/m , and AM1.5 spectrum (Standard Test Conditions, STC), the energy rating considers several characteristics of the PV module that affect the amou...
Article
Full-text available
The Capacity Value Ratio (CVR), or the part of its capacity that a technology can supply during peak residual load hours, is an important concept in the context of future resource adequacy. Especially for distributed resources, this is still underexplored territory. In this research, we investigate the peak reduction potential on both the distribut...
Conference Paper
Full-text available
The business case of vehicle-to-grid (V2G) technology and its potential to provide grid services is heavily dependent on the round-trip efficiency of this technology. Surprisingly, very little empirical research is conducted to determine the V2G round-trip efficiency of electric vehicles currently available in the market, resulting in a wide range...
Article
Full-text available
With high electric vehicle (EV) adoption, optimization of the charging process of EVs is becoming increasingly important. Although the CO2 emission impact of EVs is heavily dependent on the generation mix at the moment of charging, emission minimization of EV charging receives limited attention. Generally, studies neglect the fact that cost and emi...
Article
Full-text available
This paper explores a future perspective to foster the provision of balancing services to the electricity grid by distributed assets. One recent test case, initiated by the Dutch Transmission System Operator (TSO), was to operate an Electric Vehicle (EV) fleet on the automatic Frequency Restoration Reserve (aFRR) market, which entails fast and auto...
Preprint
Full-text available
The transition towards a sharing economy and the increasing electrification of the transport sector are occurring simultaneously. Consequently, we can expect more car sharing schemes using electric vehicles (EVs) to emerge in coming years. Numerous studies looked into the grid impact of EV charging and its potential to provide ancillary services, b...
Article
Full-text available
For the optimization of solar‐to‐electricity conversion efficiency of luminescent solar concentrators (LSCs) luminophores are treated as isotropic emitters. As rod‐shaped nanocrystals are being developed, their anisotropic emission properties may be beneficial for LSC efficiency, as it is expected that escape cone losses can be reduced by proper al...
Article
Characterizing short-term variability of generated solar power is important for the integration of photovoltaic (PV) systems into the electrical grid. Using different kinds of high frequency, in-situ observations of both irradiance and generated PV power, we quantify insights on temporal averaging effects on the highest observed peaks and ramp rate...
Article
Full-text available
A key challenge for the roll-out of public charging infrastructure is that electric vehicles are needed to function both as a clean mode of transportation and as part of a sustainable electricity system, while being cost-effective. Translating these high-level policy goals to a coherent roll-out strategy is not trivial. We address this by analyzing...
Technical Report
Full-text available
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)
Article
Full-text available
The purpose of this study is to model, simulate, and compare the performance of a photovoltaics system on land and at sea. To be able to have a fair comparison the effect of sea waves, wind speed and relative humidity are considered in this model. The sea waves are modeled in the frequency domain, using a wave spectrum. The irradiation on a tilted...
Article
Full-text available
Urban environments can be key to sustainable energy in terms of driving innovation and action. Urban areas are responsible for a significant part of energy use and associated greenhouse gas emissions. The share of greenhouse gas emissions is likely to increase as global urban populations increase. As over half of the human population will live in c...
Article
Full-text available
In this paper, an integrated blockchain-based energy management platform is proposed that optimizes energy flows in a microgrid whilst implementing a bilateral trading mechanism. Physical constraints in the microgrid are respected by formulating an Optimal Power Flow (OPF) problem, which is combined with a bilateral trading mechanism in a single op...
Article
Full-text available
While the large-scale deployment of photovoltaics (PV) for generating electricity plays an important role to mitigate global warming, the variability of PV output power poses challenges in grid management. Typically, the PV output power is dependent on various meteorological variables at the PV site. In this paper, we present a systematic approach...
Article
Full-text available
The need to limit climate change has led to policies that aim for the reduction of greenhouse gas emissions. Often, a trade-off exists between reducing emissions and associated costs. In this paper, a multi-objective optimization framework is proposed to determine this trade-off when operating a Community Energy Storage (CES) system in a neighbourh...
Article
Full-text available
Cloud transients cause rapid fluctuations in the output of photovoltaic (PV) systems, which can significantly affect the voltage levels in a low-voltage (LV) grid with high penetration of PV systems. These voltage fluctuations may lead to violation of the existing power quality standards. This study estimates the impact of rapid PV output fluctuati...