The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Brian Norton - One of the best experts on this subject based on the ideXlab platform.

Philip C. Eames - One of the best experts on this subject based on the ideXlab platform.

  • DIURNAL REVERSE FLUID FLOW IN THERMOSYPHON EVACUATED TUBE SOLAR WATER HEATERS IN A NORTHERN Maritime Climate
    2007
    Co-Authors: David A.g. Redpath, Philip C. Eames
    Abstract:

    Proprietary evacuated tube solar water heaters have superior thermal performance in Northern Maritime Climates compared with proprietary flat plate solar water heaters. Typically delivering 5-15% more thermal energy per annum, this is, however, achieved with higher capital costs. The adoption of thermosyphon fluid circulation compared with forced circulation systems allows the capital cost of solar water heating systems to be reduced, reliability increased and similar levels of performance to be achieved, for well designed systems. The thermal performance of an evacuated tube solar water heater system utilising thermosyphon fluid circulation subjected to Northern Maritime climatic conditions at the University of Ulster was monitored from the 23 rd of September to 21 st of November 2006. Measurements including collector outlet temperatures, mean bulk tank temperatures, ambient temperatures, and incident solar radiation levels were used to determine diurnal efficiency. The manifold of an evacuated tube solar water heater was inclined at 1˚: the manifold outlet being higher than the inlet. During the monitoring period it appeared that thermosyphon flow did not always occur in the direction expected. It was deduced that flow reversal had occurred when the collector inlet temperature was greater than that of the outlet. Comparison of the calculated diurnal efficiency for the days when flow reversal occurred with those when it did not indicated that flow reversal reduced the mean calculated diurnal efficiency by approximately 13%.

  • annual performance of heat retaining integrated collector storage solar water heaters in a northern Maritime Climate
    Solar Energy, 2001
    Co-Authors: Mervyn Smyth, Philip C. Eames, Brian Norton
    Abstract:

    The annual performance of two full-size integrated collector/storage solar water heaters (ICSSWH) was experimentally determined. The ICSSWHs incorporated a novel heat retaining storage vessel and employed a new technique for the construction and assembly of the encompassing collector unit. Systems A and B were respectively a 1.5 m long ICSSWH unit partially enclosed within the reflector sections and a 1.0 m long ICSSWH unit fully enclosed within the reflector sections. Details of the annual measured performance of the two designs are presented in this paper.

Philip Griffiths - One of the best experts on this subject based on the ideXlab platform.

  • Winter Performance of Certified Passive Houses in a Temperate Maritime Climate: nZEB Compliant?
    Sustainable Building for a Cleaner Environment, 2018
    Co-Authors: Shane Colclough, Philip Griffiths, Neil Hewitt
    Abstract:

    The low-energy Passive House (PH) standard is over 25 years old and has a wealth of peer-reviewed academic publications relating to its performance in continental Europe. However, relatively little has been written about it’s recorded performance in the Temperate Maritime Climate (TMC), such as that prevailing in Great Britain and Ireland. With the requirement to build to the near Zero Energy Buildings (nZEB) standard throughout EU member states by 2020, the PH standard offers a well proven methodology of building the required low energy dwellings. This paper reviews the recorded performance of certified passive houses and compares it with the recorded performance of contemporaneous houses built to the minimum building regulations in Northern Ireland. It then and considers their suitability for achieving the nZEB standard. The metrics being recorded at five-minute intervals for the houses include:

  • Summer performance of certified passive houses In A Temperate Maritime Climate
    2017
    Co-Authors: Shane Colclough, Neil Hewitt, Philip Griffiths
    Abstract:

    The solar resource in Temperate Maritime Climates (TMC) can make a significant contribution to space heating demand given the relatively long space heating season, but is this at the cost of summer overheating? This paper reviews the recorded performance of the certified passive houses with contemporaneous houses built to the minimum building regulations in Northern Ireland. The metrics being gathered at five-minute intervals for the houses are analysed:a. occupancy profileb. indoor air temperaturec. indoor relative humidityd. indoor carbon dioxide concentrationse. outdoor temperaturef. outdoor relative humidityg. wind speedh. barometric pressurei. energy consumptionIn addition “soft” data was also gathered on the inhabitants’ perception of indoor air quality, comfort levels, heating costs etc. for both the passive and non-passive houses.Results & Conclusions. The key metrics are reported upon. In addition to the higher recorded temperatures of the passive houses, it is also seen that the average carbon dioxide concentrations are more uniform in the passive houses compared with the houses complying with the minimum building regulations. Further investigation is needed, however the possibility of high CO2 readings due to insufficient ventilation (compared with the forced ventilation system of passive houses) is targeted for further investigation as part of the ongoing monitoring project.

  • Financial analysis of an installed small scale seasonal thermal energy store
    Renewable Energy, 2016
    Co-Authors: Shane Colclough, Philip Griffiths
    Abstract:

    The financial viability of an installed solar heating system incorporating a Seasonal Thermal Energy Store (STES) for a house constructed to the low-energy Passivhaus standard is analysed. Details are provided of system costs and the recorded performance for the installation which is located in Galway, Ireland, a location which experiences a Temperate Maritime Climate. Using these figures, a financial Life Cycle Analysis has been undertaken to determine the cost effectiveness of the system in providing space heating and domestic hot water.As part of the life cycle cost analysis the effect of the treatment of the terminal value of the STES was considered. The analysis shows that irrespective of the terminal value attached to the STES, the use of solar thermal energy in combination with an STES offered a more favourable business case than the use of electricity for DHW and space heating over the 40 year time period considered. This shows that a direct space heating and DHW system incorporating STES can be economically viable in a Temperate Maritime Climate in the long term.

  • Seasonal Thermal Energy Storage and the Passivhaus - Lessons from 5 years of monitoring
    2015
    Co-Authors: Shane Colclough, Philip Griffiths, David A.g. Redpath
    Abstract:

    This paper describes the measured performance of a domestic solar heating system with a Seasonal Thermal Energy Store (STES) which is used to meet the DHW and space heating requirements for a house constructed to the Passivhaus standard. Conclusions are drawn about the extent to which solar energy can assist in achieving NZEB in a Passivhaus in Temperate Maritime Climates, and the key lessons from 5 years of monitoring are reviewed. The recorded performance demonstrates the viability of solar thermal installations in helping achieve NZEB when used in combination with a low energy dwelling constructed to the passivhaus standard in a Temperate Maritime Climate.

  • Experimental Investigation of Fluid Flow Regime in Thermosyphon Heat-Pipe Evacuated Tube Solar Water Heaters
    2008
    Co-Authors: David A.g. Redpath, Steve Lo, Philip Griffiths, Herron
    Abstract:

    Previous studies have reported that the adoption of thermosyphon fluid circulation can reduce the capital cost of solar water heating systems. Well designed thermosyphon systems are as effective as pumped systems but with lower capital and running costs. To investigate this; two experiments were undertaken. Firstly a thermosyphon heat-pipe Evacuated Tube Solar Water Heater (ETSWH) was assembled using a proprietary collector and its performance monitored under a northern Maritime Climate. Secondly a transparent physical model was fabricated to the same dimensions as the proprietary collector’s manifold and the internal fluid flow regime was observed using particle imaging velocimetry. The annual monitored performance of the thermosyphon heat-pipe ETSWH demonstrated that this system could supply a solar fraction of 0.4, 0.45 and 0.71 towards the average hot water load of a detached, semi detached and terraced dwelling respectively.

Ralph Gottschalg - One of the best experts on this subject based on the ideXlab platform.

  • Spectral irradiance measurements for photovoltaic systems in Maritime Climates
    2011
    Co-Authors: Michal Krawczynski, Matthias Strobel, Thomas R. Betts, Ralph Gottschalg
    Abstract:

    Variety of materials used to manufacture photovoltaic cells rises the question about methods of accurate reference irradiance measurements, which could be applied on a level of photovoltaic plant deployment. Mismatch between spectral sensitivity of the photovoltaic module and reference sensor used for irradiance measurements increases uncertainty of available energy rating. Significance of spectral mismatch for overall energy production rating depends also on spectral variations of the solar radiation and circumstances of their appearance. Western Europe stays under the influence of Maritime Climate which is characterized by reliable cloud cover and high humidity. Carried campaign provides analysis of the spectral radiation in Maritime Climate and discusses its impact in term of PV systems applications.

  • The effect of spectral variations on the performance parameters of single and double junction amorphous silicon solar cells
    Solar Energy Materials and Solar Cells, 2005
    Co-Authors: Ralph Gottschalg, David Infield, Thomas R. Betts, Michael J. Kearney
    Abstract:

    We present the results of an experimental investigation into the effects of spectral variations in a Maritime Climate on the performance parameters of single and double junction amorphous silicon solar cells. Such considerations are important for accurate modelling of system performance. It is shown that one can distinguish between two effects: a primary effect that results from variations in the total irradiance in the spectrally useful range of the device, and a secondary (mismatch) effect observed in double junction devices that is related to details of device structure. Results showing the impact on the short-circuit current, the current at the maximum-power-point, the fill factor and the overall efficiency are discussed.

  • PV modules real operating performance in the UK, a temperate Maritime Climate
    2004
    Co-Authors: S.r. Williams, Ralph Gottschalg, David Infield
    Abstract:

    This paper looks at PV modules real operating performance in the UK, a temperate Maritime Climate.

  • experimental study of variations of the solar spectrum of relevance to thin film solar cells
    Solar Energy Materials and Solar Cells, 2003
    Co-Authors: Ralph Gottschalg, David Infield, M J Kearney
    Abstract:

    Abstract The influence of variations in the incident solar spectrum on solar cells is often neglected. This paper investigates the magnitude of this variation and its potential influence on the performance of thin film solar cells in a Maritime Climate. The investigation centres on the analysis of a large number of measurements carried out in Loughborough, UK, at 10 min intervals over a period of 30 months. The magnitude of the spectral variation is presented both on a daily and a seasonal basis. Of the different thin film materials studied, amorphous silicon is shown to be the most susceptible to changes in the spectral distribution, with the “useful fraction” of the light varying in the range +6% to −9% of the annual average, with the maximum occurring in summer time.

  • Performance of photovoltaic modules in a temperate Maritime Climate
    2003
    Co-Authors: S.r. Williams, Ralph Gottschalg, David Infield
    Abstract:

    The energy production of photovoltaic modules is a topic of growing importance. Under real operating conditions two modules with the same name-plate efficiency may have very different energy productions, despite being installed at the same site. In this paper we investigate the performance of a variety of modules (crystalline, polycrystalline and single and multi junction amorphous silicon and cadmium telluride) installed in Loughborough in the UK. The paper investigates the reasons for the significant difference in performance of modules of the same technology and efficiency. The analysis is carried out on the basis of influence of device temperature, magnitude of irradiance, incident spectrum and age of device.

Mervyn Smyth - One of the best experts on this subject based on the ideXlab platform.

  • Cost-effective novel solar water heating developments for retrofit applications
    International Journal of Ambient Energy, 2009
    Co-Authors: M. Ramirez, Jayanta Deb Mondol, Mervyn Smyth, Aggelos Zacharopoulos, Patrick Quinlan
    Abstract:

    SYNOPSIS The retrofit solar water heating market represents the greatest single area in the UK where significant application of solar energy capture can be achieved. However, many barriers exist to wide-scale implementation. Cost-effectiveness is by far the greatest single factor, created by high installation cost and reduced solar collection due to the typical prevailing solar conditions in a Northern Maritime Climate. The installation of a solar water heating system typically requires disruption to the existing domestic hot water system, quite often including disruption to the auxiliary space heating system as well. Finally, the typical installation produces a certain amount of waste arising from the removal of existing components that have been, prior to the solar water heating installation, in perfectly good working order. Two alternative novel retrofit solutions have been identified and their advantages over current installation practice presented. Both systems have been shown to offer a substantial ...

  • annual performance of heat retaining integrated collector storage solar water heaters in a northern Maritime Climate
    Solar Energy, 2001
    Co-Authors: Mervyn Smyth, Philip C. Eames, Brian Norton
    Abstract:

    The annual performance of two full-size integrated collector/storage solar water heaters (ICSSWH) was experimentally determined. The ICSSWHs incorporated a novel heat retaining storage vessel and employed a new technique for the construction and assembly of the encompassing collector unit. Systems A and B were respectively a 1.5 m long ICSSWH unit partially enclosed within the reflector sections and a 1.0 m long ICSSWH unit fully enclosed within the reflector sections. Details of the annual measured performance of the two designs are presented in this paper.