Browsing by Author "Sonneveld, P.J."

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High-Concentration Solar Energy Systems for the Built Environment
Smit, M.A. ; Catau, R.G. ; Sonneveld, P.J. ; Cremer, H.A.P. ; Sluijs, M.V. van der
2018, Part of book or chapter of book (Urban and Transit Planning)
Innovaties in duurzame energie: de oplossing om uit de crisis te komen : Portret: Piet Sonneveld
Sonneveld, P.J.
2014, Article / Letter to editor (Thematische impuls: Energie, vol. 2014, iss. januari, (2014), pp. 60-63)Toen dr. ing. Piet Sonneveld ruim twee jaar geleden als lector Duurzame Energie bij de Hogeschool van Arnhem en Nijmegen (HAN) begon, had hij een stoel, een bureau, een telefoon en een laptop. ‘Voor het onderwijs was wel plaats gereserveerd, maar voor onderzoek was er fysiek, gevoelsmatig en organisatorisch eigenlijk nog geen ruimte. Ik moest het van de grond opbouwen.’
Climate Control of a Greenhouse with Concentrating Solar Power System : International Conference on Agricultural Engineering
Sonneveld, P.J. ; Bochove, I. van
2013, Article in monograph or in proceedings (International Conference on Agricultural Engineering)There are several greenhouses built with solar panels integrated into the roof. In summer time this will operate very well, although broad shadow stripes can result in growth and yield differences. In winter the amount of sunlight is further limited by the solar panels and will result in further reduction of light accession to the cultivation space. As a result, the crops suffer from growth problems. These drawbacks are eliminated by the application of Concentrating Power Systems (CSP) with Fresnel lenses. A Fresnel lens works like a normal lens but is much thinner. When the sun shines, the lens receives both direct and indirect sunlight. The lens will concentrate all direct sunlight, which can be collected as thermal energy in the focal point. This absorbed radiation can be converted with an absorption cooler into cold water for cooling. This cold water can cool the greenhouse without the need of water use. The indirect solar radiation, the diffuse light will not focus and is therefore available as a fairly constant light source in the building or in the greenhouse. The capture of all direct radiation at high intensities will diminish the incoming heat load, which is useful for a better internal climate control of greenhouses and buildings. This lower heat load makes it easier to keep the greenhouse cool with the absorber. In this study the details of energy flows and thermal conversion with absorption cooler is determined. Calculation shows a 47% heat load reduction (from 337 W/m2 to 157 W/m2) with the Fresnel lenses in the covering of the greenhouse. In the case of the collector in focus, only 48% of the captured direct radiation, available as thermal energy, is required to cool the greenhouse further with an absorption cooler. Cooling a greenhouse can result in up to 90% reduction in water consumption of the cultivation. The possibility of light regulation is another important advantage the Fresnel lenses have. The light amount can vary between 15 – 77% of the incoming radiation. The access of the generated energy can be used for extra illumination (light and energy regulation) and/or energy supply and/or a desalination system.
Investigation the Advantages of CPV for Building Integrated PV : 28th European Photovoltaic Solar Energy Conference
Sonneveld, P.J. ; Craats, S. van der ; Sparemberger, A.R. ; Sahedi, J.V. ; Catau, R.G.
2013, Article in monograph or in proceedings (28th European Photovoltaic Solar Energy Conference)The objective of this concept is a significant reduction of energy consumption in greenhouses and buildings with large facades and windows by using available solar energy. The scope of this investigation is to study the advantages of a building integrated CPV system. The basic idea is that a larger fraction of the available solar energy can be converted to useful energy, a better indoor climate and higher crop yield (for greenhouses). The building integrated CPV systems as proposed is able to deliver at least four benefits for buildings: Electrical- and thermal energy generation, illumination by using the remaining diffuse light and better indoor climate circumstances which arise by the removal of the energy-rich direct radiation. Yields for the Dutch climate situation are estimated to be 120 kWh/m2 of electrical energy and 300 kWh/m2 thermal energy, which can be used for energy supply and/or operation of an extra cooling system. These figures can be translated in financial benefits: Calculated payback time is six year for the system that is presented here.
A novel structured plastic substrate for light confinement in thin film silicon solar cells by a geometric optical effect
Baggerman, J. ; Swinkels, Gert-Jan ; Sonneveld, P.J. ; Rijn, C.J.M. van ; Schropp, R.E.I. ; Holterman, H.J. ; Hamers, K. ; Rath, J.K. ; Jong, Reinhard de
2012, Article / Letter to editor (Journal of Non-Crystalline Solids, vol. 17, iss. 358, (2012), pp. 2308-2312)We present a novel method to achieve light trapping in thin film silicon solar cells. Unlike the commonly used surface textures, such as Asahi U-type TCO, that rely on light scattering phenomena, we employ embossed periodically arranged micro-pyramidal structures with feature sizes much larger than the wavelength of visible light. Angular resolved transmission of light through these substrates indeed showed diffraction patterns, unlike in the case of Asahi U-type substrates, which show angular resolved scattering. Single junction amorphous silicon (a-Si) solar cells made at 125 °C on the embossed structured polycarbonate (PC) substrates showed an increase in current density by 24% compared to a similar solar cell on a flat substrate. The band gap and thickness of the i-layer made by VHF PECVD are 1.9 eV and 270 nm respectively. A double p-layer (nc-Si:H/a-Si:H) was used to make proper contact with ZnO:Al TCO. Numerical modeling, called DokterDEP was performed to fit the dark and light current–voltage parameters and understand the characteristics of the cell. The output parameters from the modeling suggest that the cells have excellent built-in potential (Vbi). However, a rather high recombination voltage, Vµ, affects the FF and short circuit current density (Jsc) for the cells on Asahi as well as for the cells on PC. A rather high parallel resistance » 1 MO cm2 (obtained from the modeling) infers that there is no significant shunt leakage, which is often observed for solar cells made at low temperatures on rough substrates. An efficiency of more than 6% for a cell on PC shows enormous potential of this type of light trapping structures.
Design of a NIR concentrator system integrated in a greenhouse
Sonneveld, P.J. ; Swinkels, Gert-Jan ; Janssen, H.J.J. ; Tuijl, E.A. van
2012, Article / Letter to editor (Acta Horticulturae, iss. 952, (2012), pp. 523)In this paper the design and development of a new type of greenhouse with an integrated filter for reflecting near infrared radiation (NIR) and a solar energy delivery system is described. Especially the optical parts as the spectral selective film, the properties of the circular reflector and the efficiencies of photo voltaic cells are studied. As a first measure, the spectral selective cover material, which prevents the entrance of NIR radiation, is investigated. It has to block up to 35% of the solar energy outside the greenhouse, which will reduce the needed cooling capacity. The second measure is the integration with a solar energy system. When the NIR reflecting coating is designed as a circular shaped reflector integrated in the greenhouse, the reflected solar energy of a PhotoVoltaic (PV) cell in the focus point delivers electric energy. With a ray tracing computer program the optimal geometry of the reflector was designed with respect to the collecting efficiency. The PV cells mounted in the focal point require cooling due to the high heat load of the concentrated radiation (geometric concentration factor of 30). The properties of different PV materials were investigated to find the optimal cell for this application. Cooled greenhouses are an important issue to cope with the combination of high global radiation and high outdoor temperatures. All parts are integrated in a 100m2 prototype greenhouse which will be applied for the proof of principle.
Greenhouse with a CPV system and NIR reflecting lamellae
Janssen, H.J.J. ; Tuijl, E.A. van ; Swinkels, Gert-Jan ; Sonneveld, P.J. ; Bot, G.
2012, Article / Letter to editor (Acta Horticulturae, iss. 927, (2012), pp. 43)In previous research a new type of greenhouse with an integrated concentrated photovoltaic system (CPV) was developed based on a circular covering geometry and an integrated filter for reflecting the near infrared radiation (NIR) of the greenhouse and exploiting this radiation in a solar energy system. The performance of the system was promising. In this study further optimalisation of the CPV system is made to avoid the large construction for solar tracing and the high investment. Hereto all parts for the solar concentrating system will be integrated into the greenhouse. The NIR-reflector material is carried out as a NIR-reflective lamellae system and the CPV-module is mounted into the ridge. In this paper the results of the optimization process of the CPV system based on NIR reflecting lamellae is presented. The optimization process is based on a maximal total annual electricity production and is performed with a ray tracing model and actual radiation data. Results show that the optimization of the lamellae greenhouse can be seen from a theoretical and a practical point of view. Theoretically, the number of lamellae for the investigated concept must be high (>100) and focus with a generic focal length of 3.5 m and glazing bars must be avoided. Then the maximal annual electricity output can be over 26 kWh/m2. In practice, mechanical restrictions, plant conditions and costs will determine the implementation. The proposed CPV-system has positive side-effects like reducing the heat load (and the need for cooling) during summer and blocking of the direct radiation which can be harmful for some crops. With this, the feasibility of the system depends greatly on local conditions which require a tailor-made economic analysis.
Up scaling and test results of an advanced Fresnel greenhouse
Tuijl, E.A. van ; Janssen, H.J.J. ; Zwart, H.F. de ; Sonneveld, P.J. ; Swinkels, Gert-Jan
2012, Article / Letter to editor (Acta Horticulturae, iss. 952, (2012), pp. 531)A greenhouse with Fresnel lenses in the south facing roof and a receiver for concentrated Photovoltaics with water cooling (CPVT system) will result in electrical and thermal energy output from the solar energy excess entering a greenhouse. The PV system converts about half of the direct radiation into heat and electricity. During periods with direct radiation this will significantly reduce the heat load on the greenhouse. For an optimal performance the roof elements must be asymmetric with a steep inclination at the north side (the exact angle of course depends on the latitude of the building site). The Fresnel lens structure is best oriented in upwards direction. In the current design, two lenses are placed in the inner space of a double glass. This prevents pollution and condensation on the lenses. By the upward facing of the lens structure, the focus quality is preserved over a much broader range of angles of incidence compared to a lens with downward facing structures. Each PMMA lens with a size of 1.20×1.52 m is composed of 12 ‘tiles’ for easy production. The focal distance of the lens is 1,875 m and the geometrical concentration factor is 50×. This means that in most cases the focus line is thinner than 3 cm. The performance of the lens with respect to the shape of the focal area and the position of the focal line has been analyzed with ray tracing techniques. From this analyses and by the development of a smart tracking system only two motors can bring the receivers in the required positions. One motor controls the distance between lens and receiver and the other controls the translocation of the receivers parallel to the lens. The second conclusion was that the positions of the focal line are within the bounds of the greenhouse construction for almost the whole year. Only in winter, in the early morning and at the end of the day, the focal line will be unreachable. The 480 m2 greenhouse, with the LCPVT system based on Static Fresnel lenses and a 40 m CPVT-module and a 200 m CT-module, is designed by Bode Project Engineering and constructed by Technokas in Bleiswijk the Netherlands.
Utilization of geometric light trapping in thin film silicon solar cells: simulations and experiments, Progress in Photovoltaics: : Research and Applications
Rijn, C.J.M. van ; Rath, J.K. ; Schropp, R.E.I. ; Sonneveld, P.J. ; Baggerman, J. ; Jong, Reinhard de
2012, Article / Letter to editor (Progress in Photovoltaics: Research and Applications, (2012))In this study, we present a new light absorption enhancement method for p-i-n thin film silicon solar cells using pyramidal surface structures, larger than the wavelength of visible light. Calculations show a maximum possible current enhancement of 45% compared with cells on a flat substrate. We deposited amorphous silicon (a-Si) thin film solar cells directly onto periodically pyramidal-structured polycarbonate (PC) substrates, which show a significant increase (30%) in short-circuit current over reference cells deposited on flat glass substrates. The current of the cells on our pyramidal structures on PC is only slightly lower than that of cells on Asahi U-type TCO glass (Asahi Glass Co., Tokyo, Japan), but suffer from a somewhat lower open circuit voltage and fill factor. Because the used substrates have a locally flat surface area due to the fabrication process, we believe that the current enhancement in the cells on structured PC can be increased using larger or more closely spaced pyramids, which can have a smaller flat surface area.
Tijd voor duurzame energie : Intreerede lector Piet Sonneveld
Sonneveld, P.J.
2012, Inaugural lecture Er is veel maatschappelijke aandacht voor duurzame energie. Vooral omdat duurzame energie een belangrijke bijdrage kan leveren aan de oplossing van de klimaatproblematiek. Er zijn diverse indicatoren die aangeven dat klimaatverandering optreedt. De drie belangrijkste indicatoren voor klimaatverandering zijn de CO2-concentratie in de atmosfeer, de gemiddelde temperatuur op aarde en het ijsoppervlak op aarde.
Energy performance of a concentrated photovoltaic energy system with static linear Fresnel lenses integrated in a greenhouse
Tuijl, E.A. van ; Sonneveld, P.J. ; Campen, J. van ; Swinkels, Gert-Jan ; Janssen, H.J.J. ; Bot, G.
2011, Article / Letter to editor (Solar Energy, vol. 2011, iss. 85, (2011), pp. 432-442)A new type of greenhouse with linear Fresnel lenses in the cover performing as a concentrated photovoltaic (CPV) system is presented. The CPV system retains all direct solar radiation, while diffuse solar radiation passes through and enters into the greenhouse cultivation system. The removal of all direct radiation will block up to 77% of the solar energy from entering the greenhouse in summer, reducing the required cooling capacity by about a factor 4. This drastically reduce the need for cooling in the summer and reduce the use of screens or lime coating to reflect or block radiation. All of the direct radiation is concentrated by a factor of 25 on a photovoltaic/thermal (PV/T) module and converted to electrical and thermal (hot water) energy. The PV/T module is kept in position by a tracking system based on two electric motors and steel cables. The energy consumption of the tracking system, ca. 0.51 W m-2, is less than 2% of the generated electric power yield. A peak power of 38 W m-2 electrical output was measured at 792 W m-2 incoming radiation and a peak power of 170 W m-2 thermal output was measured at 630 W m-2 incoming radiation of. Incoming direct radiation resulted in a thermal yield of 56% and an electric yield of 11%: a combined efficiency of 67%. The annual electrical energy production of the prototype system is estimated to be 29 kW h m-2 and the thermal yield at 518 MJ m-2. The collected thermal energy can be stored and used for winter heating. The generated electrical energy can be supplied to the grid, extra cooling with a pad and fan system and/or a desalination system. The obtained results show a promising system for the lighting and temperature control of a greenhouse system and building roofs, providing simultaneous electricity and heat. It is shown that the energy contribution is sufficient for the heating demand of well-isolated greenhouses located in north European countries.
Effect of condensation on light transmission and energy budget of seven greenhouse cover materials
Mohammadkhani, V. ; Swinkels, Gert-Jan ; Stanghellini, C. ; Sonneveld, P.J. ; Bruins, M.A.
2011, Article / Letter to editor (Acta Horticulturae, iss. 952, (2011), pp. 249-254)Model calculations and the few data that are available show that over 100 L water condense yearly on each square meter of a greenhouse cover. It is known that the presence of condensate reduces light transmission. This effect is suppressed to some extent by adding film-forming (anti-drop) additives to plastic film covers and surface structures or coatings on hard cover materials. There is a need, therefore to assess the effect of the surface treatment on the loss of light. On the other hand, condensation releases the energy that was used for evaporation, thereby warming-up the cover and somewhat decreasing the heating requirement of the greenhouse. The amount of condensation energy that is recovered may be expected to depend on the external and internal climate conditions. In this work we analysed the effect of condensation on light transmission and energy budget of a greenhouse, with seven different cover materials. Various internal vs external conditions were created by placing the model greenhouse (about 3?4 m) in a large climate chamber. Each experiment was repeated for two temperature differences between inside and outside (10 and 20°C) and two air movements in the greenhouse (7.5 and 15 cm s-1). Light transmissivity was reduced by 9% on average, with large differences among materials. Anti-drop coatings did suppress this effect, as did a surface structure meant to increase light diffusivity of the material. As far as energy is concerned, the overall heat transfer coefficient (U-value) of the greenhouse increased by an average of 16% (single layers) or 12% (double layer covers) when wet. Obviously there was an effect of the temperature difference on the U-value, which was found to be consistent with the heat transfer theory, whereas little effect was found of the air movement within the house.
Lenses Based Concentrated PV system in a Greenhouse
Fresnel, A. ; Tuijl, E.A. van ; Janssen, H.J.J. ; Sonneveld, P.J. ; Swinkels, Gert-Jan
2011, Article / Letter to editor (Acta Horticulturae, iss. 893, (2011), pp. 343-350)The scope of this investigation is the development and testing of a new type of greenhouse with an integrated linear Fresnel lens, receiver module and an innovative system for tracking to exploiting all direct radiation in a solar energy system.
CPV System with Static Linear Fresnel Lenses in a Greenhouse
Sonneveld, P.J. ; Zahn, H. ; Swinkels, Gert-Jan
2010, Article / Letter to editor (AIP Conference Proceedings, iss. 1277, (2010), pp. 264-267)A new CPV system with a static linear Fresnel lens, silicon PV module suitable for concentrated radiation and an innovative tracking system is integrated in a greenhouse covering. The basic idea of this horticultural application is to develop a greenhouse for pot plants (typical shadow plants) which don’t like high direct radiation. Removing all direct radiation will block up to 77% of the solar energy, which will reduce the necessary cooling capacity. The solar energy focused on the Thermal Photovoltaic (PV/T) module generates electric and thermal energy. The PV/T module is tracked in the focal line and requires cooling due to the high heat load of the concentrated radiation (concentration factor of 50 times). All parts are integrated in a greenhouse with a size of about 36?m2. The electrical and thermal yield is determined for Dutch climate circumstances. Some measurements were performed with a PMMA linear Fresnel lens between double glass. Further improvement of the performance of the CPV-system is possible by using a PDMS lens directly laminated on glass and using AR-coated glass. This lens is developed with ZEMAX and the results of the Ray-tracing simulations are presented with the lens structure oriented in an upwards and downwards position. The best performance of the static linear Fresnel lens is achieved with upwards orientation of the lens structures. In practice this is only possible with the Fresnel lens placed between a double glass structure, which will keep the lens clean and free of water.
CPV system based on NIR reflecting lamellae integrated into a greenhouse: Optimizing of Optics
Sonneveld, P.J. ; Swinkels, Gert-Jan
2010, Article / Letter to editor (Advances in Science and Technology, 5th Forum on new materials Part C, iss. 74, (2010), pp. 297-302)In an previous research project a new type of greenhouse with an integrated concentrated photovoltaic system (CPV) was developed which has an integrated filter for reflecting the near infrared radiation (NIR) to the greenhouse and exploiting this radiation in a solar energy system. The performance of the system was promising. In this study further optimalisations of the CPV system are made to avoid the large construction for solar tracting. Hereto all parts will be integrated into the greenhouse. The NIR-reflector material is carried out as a NIR-reflective lamllea system and the CPV–module is mounted into the ridge. In this paper the results of the optimization process of the CPV system based on NIR reflecting lamellae is presented. The optimization process is based on a maximal total annual electricity production and is performed with a ray tracing model and actual radiation data. Results show that the optimization of the lamellae greenhouse can be seen from a theoretical and a practical point of view. Theoretically, the number of lamellae for the investigated concept must be high (>100) and focus with a generic focal length of 3.5 m and glazing bars must be avoided. Then the maximal annual electricity output can be over 26 kWh/m². In practice, mechanical restrictions, plant conditions and costs will determine the implementation. The proposed CPV-system has positive side-effects like reducing the heat load (and need for cooling) during summer and blocking of the direct radiation which can be harmful for some crops. With this, the feasibility of the system depends greatly on local conditions which require a tailor-made economical analysis
Feasibility study for combining cooling and high grade energy production in a solar greenhouse
Flamand, G. ; Bot, G. ; Swinkels, Gert-Jan ; Sonneveld, P.J.
2010, Article / Letter to editor (Biosystems Engineering, iss. 105, (2010), pp. 51-58)Throughout the world greenhouse horticulture is expanding and intensifying. The expansion is driven by the much higher production levels that are achieved in greenhouses compared to open fields. This provides increased income for farmers and a positive effect on rural development. Intensification is driven by the demand for better control of the production process resulting in higher yield but, more importantly, higher product quality. As a result products can meet the standards of the fast expanding consumer market for high quality fresh products, driven by the booming new economies. However greenhouse horticulture also faces major problems. In northern countries, with cold winter climates, greenhouses have to be heated for optimal growing conditions so energy supply is an important issue. In the southern countries with the combination of high global radiation and high outdoor temperatures during summer, cooling of greenhouses is needed during this period. Solutions for energy supply in winter and cooling in summer can be combined applying seasonal storage of excess solar energy and exploiting this for heating in winter. The advantage of this system is cheaper cooling, and energy savings of about 35% compared to heating by furnace. The disadvantage is that the excess solar energy is converted to low grade thermal energy which is stored at a temperature level of about 18 °C. This can only be exploited for heating in winter by a heat pump, driven by high grade energy such as electricity. Here, the feasibility of a novel approach is investigated of a greenhouse design combining cooling with energy supply in such a way that excess solar energy is directly converted to high grade electric energy. A prototype greenhouse according to this design is under construction. In a following paper the experimental results of this prototype greenhouse will be presented.
Measurements on a solar greenhouse combining cooling and electrical energy production
Tuijl, E.A. van ; Sonneveld, P.J. ; Janssen, H.J.J. ; Campen, J. van ; Bot, G. ; Swinkels, Gert-Jan
2010, Article / Letter to editor (Biosystems Engineering, iss. 106, (2010), pp. 48-57)Performance results are given of a new type of greenhouse, which combines reflection of near infrared radiation (NIR) with electrical power generation using hybrid photovoltaic cell/thermal collector modules. Besides the generation of electrical and thermal energy, the reflection of the NIR will result in improved climate conditions in the greenhouse. In a previous paper (Sonneveld, P. J., Swinkels, G. L. A. M., Bot, G. P. A., & Flamand, G. (2010). Feasibility study for combining cooling and high grade energy production in a solar greenhouse. Biosystems Engineering, 105, 51–58) a design and feasibility study of this electricity-producing greenhouse was presented. After the description of the construction of this greenhouse, the peak power for Dutch climate circumstances is determined based on the amount of electrical and thermal energy (hot water) produced. The typical yearly yield of this greenhouse system is determined as a total electrical energy of 20 kW h m-2 and a thermal energy of 160 kW h m-2. Improvements are possible in the spectral range of the NIR film and in the focusing unit of the system. In future the improved electricity-producing greenhouse system could generate 31 kW h m-2 of electrical energy and 270 kW h m-2 of thermal energy, so it could operate independent of fossil fuels.
Design of a Solar Greenhouse with Energy Delivery by the Conversion of Near Infrared Radiation - Part 1 Optics and PV-cells
Swinkels, Gert-Jan ; Sonneveld, P.J. ; Bot, G.
2009, Article / Letter to editor (Acta Horticulturae, iss. 807, (2009), pp. 47-53)In this paper the design and development of a new type of greenhouse with an integrated filter for reflecting near infrared radiation (NIR) and a solar energy delivery system is described. Especially the optical parts as the spectral selective film, the properties of the circular reflector and the efficiencies of photo voltaic cells are studied. As a first measure, the spectral selective cover material, which prevents the entrance of NIR radiation, is investigated. It has to block up to 35% of the solar energy outside the greenhouse, which will reduce the needed cooling capacity. The second measure is the integration with a solar energy system. When the NIR reflecting coating is designed as a circular shaped reflector integrated in the greenhouse, the reflected solar energy of a PhotoVoltaic (PV) cell in the focus point delivers electric energy. With a ray tracing computer program the optimal geometry of the reflector was designed with respect to the collecting efficiency. The PV cells mounted in the focal point require cooling due to the high heat load of the concentrated radiation (geometric concentration factor of 30). The properties of different PV materials were investigated to find the optimal cell for this application. Cooled greenhouses are an important issue to cope with the combination of high global radiation and high outdoor temperatures. All parts are integrated in a 100m2 prototype greenhouse which will be applied for the proof of principle.

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