Bjørn Petter Jelle

• Professor
• Professor at Norwegian University of Science and Technology

A newly introduced colour correction transmittance factor (CCTF) and an innovative probabilistic-to-deterministic approach were applied to create virtual clones of coloured building-integrated photovoltaic (BIPV) systems. These virtual clones calculate the current at maximum power point () by adjusting the plane-of-array irradiance according to the...

It is postulated that higher levels of ultraviolet (UV) radiation during early stages of prelife forms development accelerated life genesis by increasing the rate of recombination of long chains of ribonucleic acid (RNA) precursors. UV radiation is considered as maybe the most significant factor enabling life genesis within a rational time period o...

Solar energy's penetration at high latitudes has been boosted during recent years, but snow deposits during the winter still limit its exploitation. Therefore, various solutions for snow removal, such as icephobic coatings, increasing panels' tilt angle, and using wind flows, are being attempted to reduce snow and ice accumulation. The novelty of t...

To achieve the ambitious target of climate neutrality of the EU set out within the EU Green Deal, a reduction of energy use in the highly energy consuming building sector is critical. To achieve this, the renovation of existing buildings has been given a key role, starting with the Renovation Wave initiative. In fact, a large proportion of existing...

The world of today is experiencing an ever-increasing interest and focus on material scarcity and abundancy, energy efficiency and renewable and non-polluting energy harvesting. The main driving force of this increasing focus is global warming and climate changes due to emission of greenhouse gases to the atmosphere through various man-made process...

Decay pathogens follow dissimilar metabolic mechanisms to cause irreversible damage to woody tissues. The objective of this study is to perform inter- and intra-species microbial cell structural comparison using attenuated total reflectance Fourier transform infrared spectroscopy. Representative fungi species, causing brown rot and white rot, namel...

Hollow silica nanosphere packings (HSNSPs) can significantly suppress heat conduction through solid and gas phases due to the voids, small interparticle contact areas, and nanosized pores, showing promising potentials towards energy-efficient building applications. The HSNSPs display a two-level structure, where the solid silica nanoparticles form...

Wind-driven rain (WDR) impact is a serious exposure that affects performance of the building envelope components and systems. This study presents results from a laboratory investigation of a testing methodology of WDR intrusion in building-integrated photovoltaic (BIPV) systems. The major aspect proposed in this work is a quantification of water in...

In comparison to conventional thermal insulators, superinsulation materials (SIMs), such as silica aerogel or vacuum insulation panels, provide a similar insulation performance at half to a quarter of the material thickness but this superior thermal insulation performance typically comes at a significantly higher material cost. However, under certa...

For decades, there has been no proper thermodynamic definition of icephobicity. Some claim icephobic properties at an adhesion lower than 100 kPa, whereas others claim it when the accretion of ice is significantly prolonged. Herein we propose to use a terminology based on the type of frozen water deposition and its physical behaviour, separating ic...

The world community is shifting its focus towards energy-efficiency, material scarcity versus abundancy, and renewable and non-polluting energy sources, with an ever increasing awareness that we need to pursue sustainable solutions before it may be too late with respect to man-made climate changes and severe negative environmental impact. Thus, a l...

Wind-driven rain (WDR) exposure is a crucial impact factor to consider for building envelope components and systems. The roof being a climate screen, shields inner structures from various precipitations preventing most of the water from intruding. Although WDR exposure tests are quite common, there is a lack of studies that explore a quantification...

Despite significant advancements in fenestration technology in the last two decades, the thermal transmittance of fenestration products is still significantly higher than that of walls. This corresponds to 60% of the total energy loss of a modern building envelope through the windows. Hence, further development and improvements of fenestration prod...

VO 2 nanoparticleebased thermochromic films have shown great promise for applications in smart windows because of their relatively high luminous transmittance and solar modulation ability. To improve the lifetime of VO 2 nanoparticles, environmentally stable oxide materials such as TiO 2 , SiO 2 , and ZnO have been utilized as protecting shells. Ho...

This review brings together research on the integration aspect of photovoltaic technologies in the building sector. Buildings are among the significant contributors of negative, yet not avoidable, environmental impact. Two primary drivers are pushing the building industry toward sustainability: a goal of lowering the emission levels emitted by the...

Developing easy-to-install energy-efficient window retrofitting materials is important for reducing the heating and cooling loads of buildings. However, it is very challenging to achieve window retrofits that are simultaneously thermally insulating, visible-light transparent, and dynamically switchable in solar transmission. Here, a visibly transpa...

Tungsten oxide (WO3) thin films with various thicknesses of approximately 36, 72, 108, and 180 nm were prepared using radio frequency sputtering method. Film thickness can be controlled at nanoscale. In addition, X‐ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy were utilized for investigating morphologies...

Vanadium dioxide (VO2)–based thermochromic films are of great interest for energy-saving smart windows as they can dynamically change the solar transmittance as the ambient temperature changes. However, VO2 is thermodynamically unstable and could be easily oxidized by the oxygen and moisture in the ambient air. In this work, a durability-enhanced V...

Hollow silica nanospheres (HSNS) have been the subject of intense studies as a possible building block that may successfully bring about nano insulation materials (NIM) with substantially reduced thermal conductivity. The reported thermal conductivity values of the HSNS are currently ranged between 20 and 90 mW/(mK). In this work, we have investiga...

Building integrated photovoltaics (BIPV) has attracted increased commercial interest in recent years due to a growing focus on efficient utilization of land area and local renewable energy generation. Aesthetic aspects must be considered when photovoltaic panels are applied as building elements. Colours can be added by reflecting some of the sunlig...

As building integrated photovoltaics (BIPV) are becoming increasingly popular, the demand for optimized utilization will be increasing with respect to efficiency, aesthetics and reliability. In cold climate regions, we predict that there will also be a growing focus on how to avoid snow and ice formation on the exterior surfaces of BIPV. During the...

As the world’s focus is turned even stronger toward miscellaneous energy efficiency and saving aspects, the development of new high-performance thermal insulation materials for building applications will play an important role in this regard. The aim of the presented study is to develop an understanding for the governing thermal transport mechanism...

Highly transparent and low thermal conductivity materials have attracted great interest for the applications in window insulation in recent years. Accurate characterization of the thermal properties including thermal transmittance (U-value) and thermal conductivity of window insulation materials is very important for developing next-generation mate...

Understanding the heat transfer through confined systems at nanometer scale is of both scientific interest and technical importance. We report in this paper, a case study on the thermal conductivity of amorphous silica nanoparticles. It is found that the solid-state thermal conductivity of amorphous silica nanoparticles is size-dependent and can be...

In this study, we demonstrated that low density organosilica monoliths (LDM) containing hollow silica nanospheres (HSNS) may have a great potential for the use as thermal insulation materials. First, hydrophilic and hydrophobic HSNS have been prepared by a simple sol-gel method and have an average diameter centered around 120 nm and a shell thickne...

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Multipane glazing and windows may represent a possible way to lower energy consumption related to heating and cooling. In this study, a multipane glazing structure, more specifically a 6-pane glazing, has been constructed and investigated with regard to various properties and possibilities. The general configuration of the 6-pane glazing is describ...

Construction of a model of the measurement system (prototypes of its elements): • scanner for the drone • markers system. Development and construction of a measuring platform model for UAV and a model of a self-fixing marker for remote laser determination of geometric parameters of thesinkholesandgroundsubsidences. Conducting field tests of prototy...

The model of a remote measurement system suitable for use on mobile unmanned aerial platforms is discussed in order to provide data for mapping spatial parameters of anthropogenic landscape forms, mainly outcrops, sinkholes, subsidence basins around urbanized industrial areas, especially those covered by past and ongoing mining activities. The resu...

Aerogels represent one of the high-performance state-of-the-art thermal insulation materials of today. The low thermal conductivity of aerogels arises from the air-filled low density silica skeleton material with a typical air concentration as high as 95-99 vol%. Thermal conductivity values for commercial aerogel products are typically ranging betw...

Aerogels may have a promising future as a high-performance thermal insulation material in building envelopes, where the aerogel material achieves its very low thermal conductivity from its air-filled low density silica skeleton material with a typical air concentration as high as 95-99 vol%. An unique feature of aerogels is that they may be produce...

It is postulated that higher levels of UV radiation during early stages of prelife forms development accelerated life genesis increasing the rate of recombination of long chains of RNA precursors. UV radiation is considering as the most significant factor enabling life genesis within rational time period of less than 1 billion year. Later, increasi...

It is postulated that higher levels of UV radiation during early stages of prelife forms development accelerated life genesis increasing the rate of recombination of long chains of RNA precursors. UV radiation is considering as the most significant factor enabling life genesis within rational time period of less than 1 billion year. Later, increasi...

In the building sector, various adhesive materials are experiencing an increased usage for sealing of overlaps and joints between most commonly used building materials, around penetrations, pipes and windows for increasing the moisture tightness and the airtightness of buildings. Among the adhesive materials are adhesive tapes that are used to ensu...

Hollow silica nanospheres (HSNS) show a promising potential to become good thermal insulators with low thermal conductivity values for construction purposes. The thermal conductivity of HSNSs is dependent on their structural features such as sizes (inner diameter and shell thickness) and shell structures (porous or dense), which are affected by the...

The energy consumption in buildings contributes substantially to the worldwide energy use and greenhouse gas emissions. One of the crucial elements defining energy consumption is the building envelope, which in modern designs includes growing share of fenestration. Due to recent improvements of windows and walls, the thermal bridging effects occurr...

This literature study examines previous studies of the optical properties of snow, and attempts to tie them together with studies on the effects of shading on photovoltaic solar panels. The study presents some information on the general properties of snow and ice, including geographic extent and some conditions of snow and ice formation. General op...

Single-crystalline sodium tungsten bronze (Na-WO3) nanorods with typical diameters of 10–200 nm and lengths of several microns have been prepared via a simple hydrothermal method. The as-prepared Na-WO3 nanorods crystallize in a hexagonal structure and elongate along the <001> crystallographic direction. The as-prepared Na-WO3 nanorods have eight d...

The market share for fibre reinforced aerogel insulation materials is expected to increase as production costs are lowered, and in this context, the development of layered products with integrated aerogel is highly interesting. The effect of uniaxial compression and humidity on the thermal conductivity of commercially available aerogel insulation b...

Building Integrated Photovoltaics: A Review of Materials Science Challenges and Opportunities.

State-of-the-art thermal insulation solutions like vacuum insulation panels (VIP) and aerogels have low thermal conductivity, but their drawbacks may make them unable to be the thermal insulation solutions that will revolutionize the building industry regarding energy-efficient building envelopes. Nevertheless, learning from these materials may be...

Building integrated photovoltaics (BIPV) are becoming more common every day. They are used everywhere, from the cabin in the mountains to the modern apartment building, and with more common use, strengths and weaknesses begin to reveal themselves more and more. In the regions of the world experiencing a colder climate, ice and snow coverage present...

Building Integration of Photovoltaics at Nordic Climate Conditions

The Quest for Nano Insulation Materials Applying Hollow Silica Nanospheres

Sacrificial polystyrene (PS) templates have been used for synthesis of silica-based nano insulation materials (NIM). The PS was synthesized by a simple procedure where parameters as polyvinylpyrrolidone/styrene ratio and potassium persulfate amount were adjusted. Thereafter the PS templates were coated with silica by using tetraethyl orthosilicate...

Calcined clay is a Type Q supplementary cementing material according to EN197-1:2000. It possesses lower thermal conductivity than cement. To further improve its thermal insulation property, polymer-calcined clay complexes (PCCs) were produced in a one-pot synthesis. Two contrasting polymers, polystyrene (PS) and polyethylene glycol (PEG), were emp...

Advanced Materials Technologies - Development of New Materials within ZEB.

High-performance nano insulation materials (Hi-Per NIM) may be developed by exploiting the Knudsen effect for reduced thermal conductivity and thus making air-filled nanoporous thermal insulation materials with a nanoporous air-filled structure. NIMs with very low thermal conductivity values will enable the use of normal or thin wall thicknesses in...

The world’s attention towards energy-efficient and zero emission buildings is increasing, where one key aspect among others is to utilize non-polluting and renewable energy sources. Building integrated photovoltaics (BIPV) represent an interesting solution both for existing and new buildings. For the development of new BIPV products, it is importan...

Phase change materials (PCM) have received considerable attention over the last decade for use in latent heat thermal storage (LHTS) systems. PCMs give the ability to store passive solar and other heat gains as latent heat within a specific temperature range, leading to a reduction of energy usage, an increase in thermal comfort by smoothing out te...

The application potential of silver (Ag) nanoparticles as low-emissivity (low-e) coating materials has been discussed. Ag nanoparticles with an average diameter of about 50 nm were prepared via a wet-chemical method and applied on the surface of glass by spin coating. The as-prepared Ag nanoparticle films showed a typical surface emissivity of abou...

Advanced Materials Technologies - New Materials from ZEB.

Thermal conductivity and thermal diffusivity of ionic liquids (ILs) are investigated in this work. A hot disk method for ILs thermal conductivity and thermal diffusivity measurement is utilized. Firstly, the thermal conductivity of water is measured to check the reliability of the hot disk method. In addition, the thermal conductivity of pure ILs,...

Human beings are at a continuous learning process at various levels and with different motivations during their whole lifetime. Puzzle solving may beneficially be applied to increase the motivation, enhance the mastering apprehension, promote the creative processes, expand the ability to engage and solve miscellaneous challenges from various viewpo...

The recent building practices have shown that aerogel glazings can be used as a multifunctional building envelope component for different purposes. Nevertheless, the distinctive physical properties and energy performance of aerogel glazings suggest that building integration of aerogel glazings may create architectural challenges, aesthetic problems...

Today energy-efficient and energy-harvesting buildings experience an ever-increasing interest and demand. Building integrated photovoltaics (BIPV) may in this respect represent a powerful and versatile tool for reaching the goal of zero energy and zero emission buildings. The BIPV systems replace the outer building envelope skin, thus serving simul...

Thermal building insulation materials and solutions with their advantages and disadvantages have been treated. Both traditional, state-of-the-art and possible materials and solutions beyond these have been investigated. Examples of these are mineral wool, expanded polystyrene, extruded polystyrene, polyurethane, vacuum insulation panels, gas insula...

Electrochromic Materials Utilized for Smart Window Applications in Energy-Efficient Buildings.

Partial replacement of ordinary Portland cement with calcined clay as binder in the aerogel incorporated mortars (AIM) was shown to decrease their thermal conductivities while maintaining the mechanical strength. It was found that at an aerogel loading of between 40 vol% and 80 vol%, replacement of cement with calcined clay lowered the thermal cond...

A Review of Materials Science Research Pathways and Opportunities for Building Integrated Photovoltaics.

The building constructions investigated in this work are pitched wooden roofs with exterior vertical drainpipes and wooden load-bearing system. The aim of this research is to further investigate the building defects of pitched wooden roofs and obtain an overview of typical roof defects. The work involves an analysis of the building defect archive f...

Research within materials science photovoltaics (PV) technologies may enable and accelerate the development of highly innovative and efficient building integrated photovoltaics (BIPV) materials and systems. Sandwich, wavelength-tuned, dye sensitized, material-embedded concentrator, flexible (e.g. copper indium gallium selenide CIGS and cadmium tell...

Avoiding Snow and Ice Formation on Exterior Solar Cell Surfaces - A Review of Research Pathways and Opportunities.

A crucial property for double-glazed sealed insulating window panes is to maintain their thermal insulating properties and thus low U-values. However, degradation and thus subsequent reduction or loss of low-conductance gas concentration may occur in the sealed glazing units by their exposure to outdoor climate. The choice of spacers is important t...

Building integrated photovoltaics (BIPV) offer an aesthetical, economical and technical solution to integrate solar cells harvesting solar radiation to produce electricity within the climate envelopes of buildings. Photovoltaic (PV) cells may be mounted above or onto the existing or traditional roofing or wall systems. However, BIPV systems replace...

Vacuum insulation panels (VIP) represent a state-of-the-art high-performance thermal insulation solution. The pristine non-aged centre-of-panel thermal conductivity value for a VIP can be as low as 0.002– 0.004 W/(mK) depending on the core material. Normally, declared average values accounting for thermal bridge effects and ageing during e.g. 25 ye...

Building integrated photovoltaics (BIPV) represent a powerful and versatile tool for achieving the ever increasing demand for energy-efficient and energy-harvesting buildings of the near future. The BIPV systems offer an aesthetical, economical and technical solution to integrate solar cells harvesting solar radiation to produce electricity being a...

Cool colored materials like membrane sheets and dried coatings exhibit higher reflectances in the near infrared region compared to conventional materials of the same color and are therefore desirable, as they provide energy economy and thermal comfort in cooling-dominated climates. They can also make reflective envelopes durable, owing to their low...