23 research outputs found
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Energy generation and consumption in Ghana
Electricity consumption in Ghana is estimated to be increasing by 10% per annum due to the demand from the growing population. However, current sources of production (hydro and thermal facilities) generate only 66% of the current demand. Considering current trends, it is difficult to substantiate these basic facts, because of the lack of information. As a result, research into the existing sources of generating electricity, electricity consumption and prospective projects has been performed. This was achieved using three key techniques; review of literature, empirical studies and modelling. The results presented suggest that, current annual installed capacity of energy generation (i.e. 1960 MW) must be increased to 9,405.59 MW, assuming 85% plant availability. This is then capable to coop with the growing demand and it would give access to the entire population as well as support commercial and industrial activities for the growth of the economy. The prospect of performing this research is with the expectation to present an academic research agenda for further exploration into the subject area, without which the growth of the country would be stagnant
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Morphometric analysis of body and claw dimensions of building dwelling UK bat species: to aid knowledge of bat interactions with roosting surfaces
The increasing use of non-woven materials, such as breathable roofing membranes (BRMs) within buildings that either currently contain a bat roost or may do in the future, has led to concerns over bat safety by those involved in bat conservation in the UK. Whilst some information is currently available on the selection of roosts in roofs by bats, along with technical specifications of individual membranes, there is no research that has investigated the interactions between the two. Prior to determining the methods needed to test interactions between bats and BRMs, a series of preliminary investigations were conducted; including research and physical measurements on selected anatomical features of bats commonly found roosting in buildings in the UK. Data on body size and shape were gathered from a combination of experimental measurements of bat specimens (deceased) and information collated from literature. Data on bat claw morphology were collected by applying a method used to measure raptor talons, measurements obtained included; width, length and the curvature (hook ratio) of their claws. The results of this research provide additional information about bat body and claw morphometrics. It was found that bat species/group had a significant effect upon the length, width and curvature of the claws (to varying degrees). Pipistrelle species have the shortest and third narrowest claws, whereas serotines have the longest and widest claws on average. The curvature of the claws does not vary greatly between species; however, more variation was seen in the lower portion of the claws. The results from this research also demonstrate that the current standard industry tests do not represent the fine scale at which a bats claws interact with their roosting surfaces. Consequently, this information can be used to aid the development of industry tests for determining the suitability of BRMs for use in bat roosts
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Energy overview of Botswana: generation and consumption
Botswana has a basic need to explore its energy concept, this being its energy sources, generation and percentage of the population with access to electricity. At present, Botswana generates electricity from coal, which supplies about 29% (on average) of the country’s demand. The other 71% is imported mainly from South Africa (Eskom). Consequently, the dependence of Botswana on imports posses threats to the security of its energy supply. As a result, there is the need to understand the bases for a possible generation expansion that would substantiate existing documentation. In view of this need, this study investigates the existing energy sources as well as energy consumption and production levels in Botswana. The study would be further developed by making projections of the energy demand up until the year 2020. The key techniques that were used include; literature review, questionnaire survey and an empirical study. The results presented indicated that, current dependable operation capacity (i.e. 100MW) should be increased to 2,595 MW or more assuming 85% plant efficiency. This would then be able to meet the growing demand for energy use. In addition, the installed capacity would be able to support commercial and mining activities for the growth of the economy
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Computational fluid dynamics modelling of the air movement in an environmental test chamber with a respiring manikin
In recent years, computational fluid dynamics (CFD) has been widely used as a method of simulating airflow and addressing indoor environment problems. The complexity of airflows within the indoor environment would make experimental investigation difficult to undertake and also imposes significant challenges on turbulence modelling for flow prediction. This research examines through CFD visualization how air is distributed within a room. Measurements of air temperature and air velocity have been performed at a number of points in an environmental test chamber with a human occupant. To complement the experimental results, CFD simulations were carried out and the results enabled detailed analysis and visualization of spatial distribution of airflow patterns and the effect of different parameters to be predicted. The results demonstrate the complexity of modelling human exhalation within a ventilated enclosure and shed some light into how to achieve more realistic predictions of the airflow within an occupied enclosure
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Spatial distribution of CO2 impact on the indoor air quality of classrooms within a university
Indoor air quality (IAQ) remains a public and global concern. While CO2 does not pose health risks to occupants, high CO2 levels indicate insufficient ventilation, potentially accumulating pollutant concentrations. In buildings, occupants are identified as the main source of indoor carbon dioxide (CO2) through exhalation. Standard classrooms may have occupant density between 1.8-2.4m2/person. Therefore, the IAQ of classrooms and lecture theatres remain a concern. This study investigated airflow and contaminant (using CO2 as a proxy) distribution in two classrooms modelled using CFX a Computational Fluid Dynamics (CFD) software, verified against experimental measurements. The model provides the visualization of flow patterns so that the effects of external and internal flow fields in the classroom can be studied. The results show that there are large differences in classroom indoor ventilation performance due to the effects of wind direction and wind speed on building surface wind pressure from outdoor wind speeds. Windward high-pressure surfaces and leeward vortices created by building shading promote indoor air quality in buildings with windcatcher openings. The concentration distribution of CO in the classrooms showed an upward convergence with the thermal plume generated by the respiratory differences of the personnel and the temperature of the lighting equipment. The results of this study have important implications for improving classroom design guidelines for school buildings, especially in terms of ventilation strategies and air quality monitoring
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Bridging the gap between energy consumption and the indoor environmental quality of a 1960s-educational building
The fundamental purpose of a building has evolved from merely providing protection from external environmental climate to more emphasis on integrating building services through building regulations to provide the synergy of comfort, efficiency and safety to the indoor environment. This research recognizes the rising demand and increasing quality of indoor environmental quality (IEQ) in the modern society compared to the acceptable level of previous traditional buildings. Generally due to its varied operations, educational buildings, in this case University libraries have its own set of challenges and barriers such as minimizing damages and decay of books and maintaining indoor conditions with an oversight of providing good IEQ to occupants. This paper presents a detailed evaluation of a 1960s-educational library with 24-hour access at the University of Reading. Through in-situ measurements, modelling and simulations of the building’s energy consumption, IEQ parameters and occupancy patterns, investigations have been performed. Varied scenarios using the Integrated Environmental Solution (IES) software were also investigated. The findings illustrate that due to mixed façade configuration (i.e. sandstone and bricks) there is the unflinching need to balance aesthetics of the facade and functionality of a building to reduce excessive energy use via heating, without compromising on occupant comfort and well-being Although it is envisaged that refurbishing the library building will provide energy savings of up to 40%, this is farfetched and can only be achieved at the detriment of occupant comfort levels as evident in the simulation results, where these savings could not be realised. This paper further discusses the methods, scenarios, and results of ensuring good IEQ, comfort and energy efficiency are not been seen as mutually exclusive. This study forms part of ongoing research into the impact of educational buildings
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The impact of green facades and vegetative cover on the temperature and relative humidity within model buildings
Vertical greening solutions such as direct greening are gaining popularity due to their relatively low cost and minimal ground footprint. However, concerns about increases in relative humidity (RH) can reduce implementation.
The impact of several widely-used plant species (Hedera helix, Parthenocissus tricuspidata and Pileostegia viburnoides) on the internal/external temperature and RH on the south-facing wall of replicated experimental model ‘buildings’ was studied during summer and winter. All plant species reduced the air temperature internally/externally during the summer daytimes by at least 1 oC compared to bare ‘buildings’. Hedera produced the greatest cooling effect internally and externally, by 7.2 oC and 5.7 oC respectively. All plant species reduced daily variation in external RH and external/internal temperature during summer; Hedera reduced variation most and Pileostegia least. During night-time in both seasons, the temperature behind Hedera foliage typically remained higher, which could reduce the risk of freeze-thaw damage in winter.
The RH was not significantly elevated by vegetation except during warm afternoons in summer and winter. During warm afternoons, the external RH was significantly higher only behind the Hedera foliage compared to the bare ‘buildings’, 11% and 3.7% , summer and winter respectively. However, inside all vegetated ‘buildings’ the RH was at least 11% higher compared to the bare ‘buildings’ during summer. Yet, in winter the internal RH was 5.7% lower in the Hedera-covered compared to the bare ‘buildings’. Current building standards would prevent the transfer of external RH in this range internally, as the walls include protective layers such as damp-proof membranes
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Barriers of solar energy uptake and the potential for mitigation solutions in Barbados
Understanding the barriers that inhibit the deployment of renewable energy technologies to achieve long-term reductions in carbon emissions from the use of fossil fuels is paramount to Barbados. Although there are targets towards renewable energy (solar, wind, biomass, geothermal) uptake, the share of these technologies in the energy mix does not exist in Barbados due to the total dependence on fossil fuels. In this paper, a review of potential challenges and the main problems for deployment of alternative energy sources is presented. Through interviews, questionnaires with a focus group of key personnel’s, the paper documents the lack of renewable energy sources (with emphasis on solar energy) as one of the main alternatives to meet the carbon emission targets set by the country. The barriers and challenges facing the implementation of solar energy deployment have been clarified. From the results, it is evident that significant policy barriers still exist at the country level, which has reduced the effectiveness of a concerted national effort to deploy renewables. The current policy landscape which benefits from fossil fuel imports, the lack of technical know-how and the lack of research and development in the renewable energy space are amongst the key barriers identified. The paper also outlines the key policy’s frameworks, regulatory environment and the lack of incentives, which encompasses the renewable energy sector, and presents a critical analysis of the barriers faced by the industry. A mitigation framework is proposed to bridge the gap of solar energy (renewable energy) deployment
Energy generation and consumption in Ghana
Electricity consumption in Ghana is estimated to be increasing by 10% per annum due to the demand from the growing population. However, current sources of production (hydro and thermal facilities) generate only 66% of the current demand. Considering current trends, it is difficult to substantiate these basic facts, because of the lack of information. As a result, research into the existing sources of generating electricity, electricity consumption and prospective projects has been performed. This was achieved using three key techniques; review of literature, empirical studies and modelling. The results presented suggest that, current annual installed capacity of energy generation (i.e. 1960 MW) must be increased to 9,405.59 MW, assuming 85% plant availability. This is then capable to coop with the growing demand and it would give access to the entire population as well as support commercial and industrial activities for the growth of the economy. The prospect of performing this research is with the expectation to present an academic research agenda for further exploration into the subject area, without which the growth of the country would be stagnant
Energy generation and consumption in Ghana
Electricity consumption in Ghana is estimated to be increasing by 10% per annum due to the demand from the growing population. However, current sources of production (hydro and thermal facilities) generate only 66% of the current demand. Considering current trends, it is difficult to substantiate these basic facts, because of the lack of information. As a result, research into the existing sources of generating electricity, electricity consumption and prospective projects has been performed. This was achieved using three key techniques; review of literature, empirical studies and modelling. The results presented suggest that, current annual installed capacity of energy generation (i.e. 1960 MW) must be increased to 9,405.59 MW, assuming 85% plant availability. This is then capable to coop with the growing demand and it would give access to the entire population as well as support commercial and industrial activities for the growth of the economy. The prospect of performing this research is with the expectation to present an academic research agenda for further exploration into the subject area, without which the growth of the country would be stagnant