28 results for Anderson, Timothy Nicholas

  • Investigation of thermal aspects of building integrated photovoltaic/thermal solar collectors

    Anderson, Timothy Nicholas (2009)

    Doctoral thesis
    University of Waikato

    In this study a novel building integrated photovoltaic/thermal (BIPVT) solar collector was developed, tested, modelled and optimised both experimentally and theoretically. Experimental testing found that glazing the prototype collector improved the maximum thermal efficiency by approximately 25% and decreased heat loss, by a factor of two, relative to an unglazed collector. Additionally, the spectral absorptance of a photovoltaic (PV) cell and several coloured absorber samples were characterised. The experimental data was subsequently used in the development and validation of an optimisation model for BIPVT style collectors. Numerical optimisation showed that the collector thermal efficiency could be improved by maximising the geometric fin efficiency, reducing the thermal resistance between the PV cells and the absorber, and by increasing the transmittance-absorptance product of the PV cells and/or the absorber. The results showed that low cost materials, such as mild steel, could be used without significantly affecting the BIPVTs thermal efficiency. It was also shown that there was potential to develop coloured BIPVT collectors with acceptable thermal efficiencies. Finally, the model showed that potentially the air space in an attic could be used rather than traditional insulating materials. Subsequent computational and experimental fluid dynamics studies found that the heat transfer coefficients in a scale-model attic would result in R-values similar to mineral wool type insulation and therefore may provide sufficient insulation of a BIPVT in a cold roof building. In these studies the validity of an existing correlation for natural convection in an attic-shaped enclosure was extended to Grashof numbers in the range 10^7 to 10^9 from its previous range, 2.9 x 10^6 to 9 x 10^6. The use of a single vertically mounted baffle was also found to reduce the natural convection heat transfer coefficients in attic-shaped enclosures. This led to the development of a new generalised correlation that can be used to determine the Nusselt number in an attic-shaped enclosure with regard to the proportions of the baffle. This work has shown that it is possible to achieve satisfactory thermal performance from BIPVT style collectors fabricated from low cost materials such as colour coated mild steel. Further it has demonstrated that there is potential to reduce the cost of such systems by integrating them into a building rather than onto a building.

    View record details
  • Performance of a building integrated solar combisystem

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2010)

    Conference item
    University of Waikato

    Solar combisystems providing both water and space heating to buildings are becoming commonplace in European and North American locations. However, the use of these systems in Australia and New Zealand is still in its infancy. While significant work has been undertaken to characterise the performance of these systems in northern hemisphere locations, this does not necessarily reflect their performance in Australia or New Zealand. This work examines the performance of solar combisystems utilising TRNSYS and F-chart simulations of an integrated solar thermal combisystem installed in a single storey detached dwelling under typical Australian and New Zealand climatic conditions. In doing this, it shows that there is significant scope for increased use of solar combisystems in the cooler climate regions of Australia and New Zealand.

    View record details
  • Investigation of production systems for a building integrated photovoltaic thermal product

    Bura, Sunil Kumar; Duke, Mike; Lay, Mark C.; Anderson, Timothy Nicholas (2007)

    Conference item
    University of Waikato

    Integration of solar energy devices with building products is one of the fastest growing markets in the building industry. Building integrated products are multifunctional and fit into a standard façade or roofing structure. This paper discusses a building integrated photovoltaic thermal collector (BIPVT) capable of generating electrical and thermal energy. Different production methodologies for manufacturing of the BIPVT system are discussed. Prototypes were manufactured as per the researched production methodologies. The optimum production systems for manufacturing the building integrated system were selected from the economic analysis and performance of the manufactured prototypes.

    View record details
  • Performance of a building integrated collector for solar heating and radiant cooling

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2011)

    Conference item
    University of Waikato

    Due to their limited temperature range, unglazed solar collectors have long been relegated to providing low cost heating in applications such as swimming pool heating systems. This limited temperature range is due to heat loss: firstly by convection to the surrounding air and secondly by radiant heat transfer to the cold sky. During the day an unglazed collector can be operated as a standard solar absorber to heat water in a storage tank. However, it is possible to take advantage of radiant cooling of unglazed solar collectors by operating them at night. Under night conditions when there is no solar radiation and the sky temperature is low, the collector can radiate heat to the sky and cool a cold storage tank to provide cooling in the building the following day. This study theoretically and experimentally examines the performance of a building integrated collector for heating and cooling and explores the contribution it can make to heating and cooling loads in typical New Zealand and Australian buildings.

    View record details
  • Experimental performance of water cooled building integrated photovoltaic/thermal solar collectors

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2008)

    Conference item
    University of Waikato

    The idea of integrating water cooled photovoltaic/thermal collectors into building structures (BIPVT collectors) to provide electrical and heat energy is an area that has received only limited attention. BIPVT collectors are particularly attractive, as the integration of a single photovoltaic and thermal collector into the long-run roofing structure of a building could provide greater opportunity for the use of renewable solar energy technologies. In this study, the thermal efficiency of a novel low cost water cooled building integrated photovoltaic/thermal (BIPVT) solar collector was experimentally measured. The results show that despite being made of a typical roofing material, the thermal efficiency is not unreasonably affected. Furthermore, it is shown that the measured efficiency is similar to that predicted by the Hottel-Whillier equations.

    View record details
  • Improved electrical efficiency by active cooling of building integrated photovoltaic panels

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2007)

    Conference item
    University of Waikato

    The electrical efficiency of photovoltaic devices can be directly related to the temperature of the photovoltaic cells. The ability to actively cool building integrated photovoltaic solar panels allows their electrical efficiency to be maintained during periods of high solar radiation. Furthermore, the ability to capture and store heat from building integrated photovoltaic panels presents the opportunity for building integrated photovoltaic thermal (BIPVT) solar collectors. In this study a BIPVT solar collector was analysed and key parameters affecting its electrical efficiency were identified.

    View record details
  • Modelling and testing of long range battery electric vehicle performance

    Duke, Mike; Anderson, Timothy Nicholas (2008)

    Conference item
    University of Waikato

    There are two significant issues facing road transport in the medium to long term: the depletion of cheap oil reserves and the need to reduce carbon emissions. A long term solution for passenger cars could be the introduction of battery electric vehicles (BEVs). However, one of the main problems associated with the current generation of BEVs is their short range relative to conventional internal combustion engine (ICE) cars. To investigate this issue, a long range battery electric vehicle, the UltraCommuter (UC), was constructed by the University of Waikato in partnership with HybridAuto Ltd. This paper describes the development, modelling and testing of the UC and its performance in the 2007 World Solar Challenge.

    View record details
  • The emergence of battery electric vehicles: A NZ manufacturing opportunity?

    Duke, Mike; de Fluiter, Travis; Anderson, Timothy Nicholas; Andrews, Deborah (2006)

    Conference item
    University of Waikato

    Personal passenger transport faces several challenges in the coming decades: depletion of cheap oil reserves, increasing congestion, localised pollution, the need for reduced carbon emissions and the long term goal of sustainability. One way of solving some of these problems could be to introduce comfortable, energy efficient, battery electric vehicles. Currently, hybrid vehicles have been presented as a means to reducing the transportation related oil demand. New developments in materials and technologies have made them, cleaner and safer as well as more fuel efficient. However, hybrids will only prolong the use of oil until alternatively fuelled vehicles are developed. One long term alternative is the battery electric vehicle (BEV). A BEV designed to be light, aerodynamic with high efficiency drive train and latest battery technology would have a performance comparable to a typical internal combustion engine vehicle (ICEV). Recent developments in virtual engineering, rapid prototyping and advanced manufacturing might enable low-cost development of niche market BEV’s designed and built in New Zealand for export markets. This work examines the collaborative development of a twin seat BEV using new materials and latest technologies by the University of Waikato’s Engineering Department and a group of NZ and foreign companies. The car will be used to research the potential of BEVs and will also compete in the Commuter Class of the World Solar Challenge in 2007.

    View record details
  • Analysis of a photovoltaic/thermal solar collector for building integration

    Anderson, Timothy Nicholas; Duke, Mike (2007)

    Conference item
    University of Waikato

    The idea of combining photovoltaic and solar thermal collectors (PVT collectors) to provide electrical and heat energy is not new, however it is an area that has received only limited attention. With concern growing over energy sources and their usage, PVTs have become a focus point of interest in the field of solar energy research. Although PVTs are not as prevalent as solar thermal systems, the integration of photovoltaic and solar thermal collectors into the walls or roofing structure of a building could provide greater opportunity for the use of renewable solar energy technologies in domestic, commercial and industrial applications. As such, the design of a novel building integrated photovoltaic/thermal (BIPVT) solar collector is theoretically analysed through the use of a modified Hottel-Whillier model. The thermal efficiency under a range of conditions was subsequently determined and results showing how key design parameters influence the performance of the BIPVT system are presented.

    View record details
  • A combined optical, thermal and electrical performance model of a Building Integrated Photovoltaic/Thermal Concentrator (BIPVTC)

    Anderson, Timothy Nicholas; Künnemeyer, Rainer; Duke, Mike; Carson, James K. (2011)

    Conference item
    University of Waikato

    The electrical output of concentrating photovoltaic devices is significantly affected by the temperature of the photovoltaic cells. The ability to actively cool photovoltaic cells under concentrated radiation allows their electrical efficiency to be maintained particularly during periods of high solar radiation when concentration offers the maximum benefit. In this study, the design of a novel photovoltaic/thermal solar concentrator for building integration (BIPVTC) is discussed. The optical, thermal and electrical performance of the collector was theoretically modelled and validated with experimental data. The results show that BIPVTC offers improved electrical yields from both concentrating radiation onto the photovoltaic cells and also by actively cooling them.

    View record details
  • "Where did we go wrong?" An examination of students treatment of experimental error in engineering mechanics laboratories

    Anderson, Timothy Nicholas; Torrens, Rob; Lay, Mark C.; Duke, Mike (2008)

    Conference item
    University of Waikato

    The ability of engineers and applied scientists to undertake experimental measurements is a fundamental requirement of the profession. However, it is not simply good enough to be able to perform experiments if we are not able to interpret the results. In this study, reports prepared by mechanical engineering students were examined to determine how students dealt with the disparity between experimental measurements and theoretical results in their Engineering Mechanics laboratories. Analysis of the reports, and discussions with students in their laboratory classes, revealed a superficial understanding or regard for experimental error. This superficial treatment of experimental error is, most likely, due to a number of factors that are discussed. Some possible strategies for addressing the issue are also examined.

    View record details
  • Roofing that generates electricity and heat

    Bura, Sunil Kumar; Duke, Mike; Anderson, Timothy Nicholas; Lay, Mark C. (2008)

    Journal article
    University of Waikato

    Integrating solar energy devices with building products is a rapidly growing market in the building industry. The aim is to make solar devices that integrate into a standard facade, window, roof tile, membrane roof or long run roof. These serve as weatherproofing for a building and also generate electrical and thermal energy.

    View record details
  • An assessment of base load concentrating solar thermal power generation for New Zealand

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2011)

    Conference item
    University of Waikato

    With increasing pressure being placed on traditional energy sources, both in terms of supply and also regulatory, there is an increasing need to explore alternative generation technologies. In global terms, solar energy has the potential to make a significant contribution to worldwide energy demands in the future. This study examines recent developments in the emerging field of concentrating solar thermal power generation and explores the potential for base load electricity generation using this technology in New Zealand.

    View record details
  • Solar energy use for energy savings in dairy processing plants

    Anderson, Timothy Nicholas; Duke, Mike (2007)

    Journal article
    University of Waikato

    New Zealand is one of the world’s largest producers of dairy products and has a climate with high levels of solar radiation; however, the use of solar energy in the dairy processing industry has received limited attention. An examination of historical records found that the annual peak in New Zealand milk production and processing occurs at a time when solar radiation levels are increasing markedly. An F-Chart analysis was used to simulate the performance of large-area arrays of solar collectors and to determine their suitability for heating and cooling in a dairy processing environment. For the study four types of solar collectors were analysed: glazed flat plates, evacuated tubes, evacuated tubes with CPC reflectors and a building-integrated solar collector under development at the University of Waikato (UoW). It was found that of these technologies, both flat plate and evacuated tubes with CPC reflectors could make useful heating and cooling contributions. Furthermore, the solar fraction was determined mainly by the collector area to storage volume ratio. Finally, it was found that the UoW building-integrated solar collector could make a significant contribution to energy use in dairies and may be an attractive future technology for the industry.

    View record details
  • Measurement of natural convection heat transfer in an attic shaped enclosure

    Anderson, Timothy Nicholas; Duke, Mike; Mike, James (2008)


    University of Waikato

    Heat transfer by natural convection in triangular enclosures is an area of significant importance in applications such as the design of greenhouses, attics and solar water heaters. However, given its significance to these areas it has not been widely examined. In this study, the natural convection heat transfer coefficients for air in an attic shaped enclosure were determined for Grashof Numbers over the range of 10⁷ to 10⁹. It was found that the measured heat transfer coefficients could be predicted to within 5% by Ridouane and Campo’ (2005) equation (Eqn. 1) for natural convection in a triangular enclosure previously developed for Grashof Numbers in the range 10⁵ and 10⁶. Nu= 0.286A⁻⁰•²⁸⁶ Gr¼ (1) As such, it is suggested that this equation may be suitable for predicting the natural convection heat transfer coefficients in full scale attic enclosures.

    View record details
  • Performance of coloured solar collectors

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2009)

    Conference item
    University of Waikato

    The use of solar collectors with coloured absorbers for water heating is an area of particular interest when considering their integration with buildings. By matching the absorber colour with that of the roof or façade of the building, it is possible to achieve an architecturally and visually pleasing result. Despite the potential for the use of coloured absorbers very little work has been undertaken in the field. In this study, the thermal performance of a series of coloured, ranging from white to black, water heating solar collectors is examined. Subsequently, the annual solar fraction for typical water heating systems with coloured absorbers is calculated. The results show that coloured solar collector absorbers can make noticeable contributions to heating loads. Furthermore, although their thermal efficiency is lower than highly developed selective coating absorbers, they offer the advantage of sensitive integration with buildings.

    View record details
  • Development of a building integrated photovoltaic/thermal solar collector based on steel roofing

    Anderson, Timothy Nicholas; Bura, Sunil Kumar; Duke, Mike; Carson, James K.; Lay, Mark C. (2008)

    Conference item
    University of Waikato

    The use of onsite renewable energy cogeneration from structural building elements is a relatively new concept, and one that is gaining considerable interest in the building industry. In this study the design, development, testing and production methods for a novel building integrated photovoltaic/thermal (BIPVT) solar energy cogeneration system are examined and discussed. During the analysis of the design, adhesives (ADH), resistance seam welding (RSW) and autoclaving (ATC) were identified as the most appropriate for fabricating BIPVT panels for roofing and façade applications. Of these manufacturing methods ADH was found to be most suitable for low volume production systems due to its low capital cost. Furthermore, a prototype panel was fabricated using ADH methods and exhibited good thermal performance. In addition it was shown, using experimental testing, that the performance of a BIPVT could be theoretically predicted using a one-dimensional heat transfer model. Furthermore, the model was used to suggest further improvements that could be made to the design. Finally, a transient simulation of the BIPVT was performed in TRNSYS and was used to illustrate the long term benefits of the system.

    View record details
  • A typical meteorological year for energy simulations in Hamilton, New Zealand

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2007)

    Journal article
    University of Waikato

    Typical Meteorological Year (TMY) data is used extensively in building energy simulations and solar energy analysis. TMY data for New Zealand, however, is relatively limited and no such data existed for Hamilton. Ten years of hourly meteorological data was analysed, and a TMY was developed. Simulations using the TMY data were conducted to determine the performance of a solar pool-heating system. It was found that the TMY was able to predict the annual performance of this system to within 2% of the long-term mean. It is intended that this TMY could be used to perform simulations on building energy use and solar heating systems in Hamilton.

    View record details
  • The potential for battery electric vehicles in New Zealand

    Duke, Mike; Anderson, Timothy Nicholas (2008)

    Conference item
    University of Waikato

    Several challenges are facing personal transport in New Zealand; the need to reduce carbon emissions, the depletion of cheap oil reserves, increasing congestion, localised pollution and the need for long term sustainability. One possible solution to replace petrol/diesel cars could be the mass deployment of cost competitive, comfortable, attractive, energy efficient battery electric vehicles (BEVs). This paper first discusses the social and technical barriers that have hindered the development of this type of electric vehicle and secondly, how they can now be overcome. The electricity supply for a New Zealand fleet of 2 million battery electric cars is also discussed.

    View record details
  • Designing a low cost solar collector system for process industry applications

    Anderson, Timothy Nicholas; Duke, Mike; Carson, James K. (2008)

    Conference item
    University of Waikato

    New Zealand is a large producer and processor of primary products and has a climate with high levels of solar radiation. However, the use of solar energy for heating and cooling in the processing industries has received limited attention. For this study, the design of a low cost solar collector is analysed and discussed. Furthermore, the methods for integrating the collector into water heating and cooling systems in a hypothetical processing environment are examined. An F-Chart analysis is used to simulate the performance of large-area arrays of the solar collector and to determine its potential contribution to heating and cooling loads. The study shows that for a storage-based system, the contribution of solar energy is determined mainly by the collector area to storage volume ratio. It is suggested that this low cost collector could make a significant contribution to energy use in processing plants and may be an attractive future technology.

    View record details