Preliminary investigations on energy efficiency of manufacturing firms operating in South Africa have shown that no previous study on the barriers and drivers to energy efficiency was conducted. It was also found that South Africa is the only member within the Brazilian, Russian, Indian, Chinese and South African (BRICS) community that has not conducted any formal study on the drivers and barriers to Energy efficiency despite the current energy challenges the country faces. Whilst the National Energy Efficiency Strategy (NEES) was developed and targets were set to improve the country’s efficiency landscape, this strategy failed to account for the barriers and drivers to energy efficiency operating within the local context. This research study sets out to investigate whether an energy efficiency gap exists within manufacturing firms operating in the eThekwini Municipal Area (EMA) and by inference, the national context. It goes on further to analyse the drivers and barriers to Energy Efficiency (EE) within such firms. Such drivers and barriers are then analysed by firm characteristics and across manufacturing sectors. The results are interesting and contribute well to the general body of knowledge on EE in South Africa. It was found that whilst there is a degree of adoption and awareness of EE technologies amongst manufacturing firms, the quality of the adoption profile is poor. This poor quality profile suggests the possibility of an energy efficiency gap. The barriers and drivers that were found to be significant were also found to be mostly similar across manufacturing sectors. A main finding is that firms are very sensitive to cost and are mainly driven to adopt EE technologies only where there exists an opportunity for cost savings. It was also found that taken together, institutional barriers pose the greatest hurdle to EE adoption. Several interesting results were found in terms of how the barriers and drivers vary with the characteristics of the firm. The findings of this research indicate that more can be achieved in terms of energy efficiency within the manufacturing subsectors in South Africa. Policy-makers should take into consideration the salient findings of this research when drafting new policy on energy efficiency. / Dissertation (MEng)--University of Pretoria, 2017. / Graduate School of Technology Management (GSTM) / MEng / Unrestricted

Energy intensity in the U.S. from 1780 to 2010 shows a declining trend when traditional energy is included, in contrast to the "inverted U-curve" seen when only commercial energy is considered. The analysis quantifies use of human and animal muscle power, wind and water power, biomass, harvested ice, fossil fuels, and nuclear power. Historical prices are provided for many energy resources. The analysis reaffirms the importance of innovation in conversion technologies in energy transitions. An increase in energy intensity in the early 20th century is explained by diminishing returns to pre-electric manufacturing systems, which produced a transformation in manufacturing. In comparison to similar studies for other countries, the U.S. has generally higher energy intensity. A population-weighted series of heating degree days and cooling degree days partially explains differences in energy intensity. Series are developed for 231 countries and territories with multiple reference temperatures, with a "wet-bulb" series accounting for the effects of humidity. Other variables considered include energy prices, income per capita, and governance indices. A panel regression of thirty-two countries from 1995 to 2010 establishes GDP per capita and share of primary energy as determinants of energy intensity, but fails to establish statistical significance of the climate variables. A group mean regression finds average heating and cooling degree days to be significant predictors of average energy intensity over the study period, increasing energy intensity by roughly 1.5 kJ per 2005 international dollar for each annual degree day. Group mean regression results explain differences in countries' average energy intensity, but not changes within a country over time. Energy Return on Investment (EROI) influences the economic competitiveness and environmental impacts of an energy resource and is one driver of energy transitions. The EROI of U.S. petroleum production has declined since 1972, with a partial rebound in the 1980s and 1990s. External Energy Return (EER), which excludes the consumption of energy from within the resource, falls by two-thirds from 1972 to 2007. A literature review finds the projected EROI of oil shale to be much lower than the EROI of U.S. petroleum production.

The main objective of this paper is to show the economic and environmental benefits that can be attained through the coupling of borehole thermal energy storage (BTES) and combined heat and power (CHP). The subject of this investigation is the University of Massachusetts CHP District Heating System. Energy prices are significantly higher during the winter months due to the limited supply of natural gas. This dearth not only increases operating costs but also emissions, due to the need to burn ultra low sulfur diesel (ULSD). The application of a TES system to a CHP plant allows the plant to deviate from the required thermal load in order to operate in a more economically and environmentally optimal manner. TES systems are charged by a heat input when there is excess or inexpensive energy, this heat is then stored and discharged when it is needed. The scope of this paper is to present a TRNSYS model of a BTES system that is designed using actual operational data from the campus CHP plant. The TRNSYS model predicts that a BTES efficiency of 88% is reached after 4 years of operation. It is concluded that the application of BTES to CHP enables greater flexibility in the operation of the CHP plant. Such flexibility can allow the system to produce more energy in low demand periods. This operational attribute leads to significantly reduced operating costs and emissions as it enables the replacement of ULSD or liquefied natural gas (LNG) with natural gas.

No description available.

The cost and fuel economy of hybrid electrical vehicles (HEVs) are significantly dependent on the power-train energy storage system (ESS). A series HEV with a minimal all-electric mode (AEM) permits minimizing the size and cost of the ESS. This manuscript, pursuing the minimal size tactic, introduces a bandwidth based methodology for designing an efficient ESS. First, for a mid-size reference vehicle, a parametric study is carried out over various minimal-size ESSs, both hybrid (HESS) and non-hybrid (ESS), for finding the highest fuel economy. The results show that a specific type of high power battery with 4.5 kWh capacity can be selected as the winning candidate to study for further minimization. In a second study, following the twin goals of maximizing Fuel Economy (FE) and improving consumer acceptance, a sports car class Series-HEV (SHEV) was considered as a potential application which requires even more ESS minimization. The challenge with this vehicle is to reduce the ESS size compared to 4.5 kWh, because the available space allocation is only one fourth of the allowed battery size in the mid-size study by volume. Therefore, an advanced bandwidth-based controller is developed that allows a hybridized Subaru BRZ model to be realized with a light ESS. The result allows a SHEV to be realized with 1.13 kWh ESS capacity. In a third study, the objective is to find optimum SHEV designs with minimal AEM assumption which cover the design space between the fuel economies in the mid-size car study and the sports car study. Maximizing FE while minimizing ESS cost is more aligned with customer acceptance in the current state of market. The techniques applied to manage the power flow between energy sources of the power-train significantly affect the results of this optimization. A Pareto Frontier, including ESS cost and FE, for a SHEV with limited AEM, is introduced using an advanced bandwidth-based control strategy teamed up with duty ratio control. This controller allows the series hybrid’s advantage of tightly managing engine efficiency to be extended to lighter ESS, as compared to the size of the ESS in available products in the market.

No description available.

Thesis (M.P.A.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 133-137).

Thesis (M.P.A.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 133-137). Also available in print.

The collateral effects of fossil fuels push humanity to seek solutions to these adversities. Energy efficiency and renewable energies have gone from being almost imaginary concepts to necessary. Several studies have shown that self-sufficiency through photovoltaic systems and wind energy is possible. In addition, it is necessary a storage of the surpluses of both since it increases notably the efficiency of these systems and supposes to the short/medium term a saving of money in the consumer. Due to the mentioned before, the aim of the thesis is to convert a science park located in a cold climate such as Sweden into a complex that does not depend energetically on external sources. For this purpose, a series of data from the park were first collected and then simulated and optimised using the HOMER software for different energy configurations. At the same time, a computer code was created in MatLab to enable the energy produced to be used responsibly. The proposed system consists of PV panels, wind turbines and a battery. Thanks to it, a 64 % renewable fraction is achieved, which means a reduction of 27.45 tons of CO2 per year. In addition, through the energy management system created, the electricity contract is reduced, reducing the purchase of electricity during peak hours. It is concluded that the implementation of both proposed systems contributes significantly to the achievement of the sustainable goals set for 2 030 by the main world leaders, even though a total disconnection with the electrical grid has not been achieved.

Energy access has gained a lot of attention following the adoption of the Sustainable Development Goals (SDG), which under Goal 7 emphasizes the access to affordable, reliable, sustainable and modern energy for all. Energy is central in addressing the major global challenges of the 21st century, including poverty, climate change, famine to mention but a few; and yet a large number of people especially in Sub-Saharan Africa (SSA) still lack access to modern energy, such as electricity, natural gas and liquefied natural gas (LNG) for lighting and cooking respectively. Initiatives have been taken at an international, regional and national level to address the issue of energy access, however, the problem continues to escalate in SSA. SSA countries have common energy challenges which could be tackled with common efforts through regional cooperation. Achieving cooperative outcomes can be difficult among countries on a bilateral basis. In this regard, the employment of a broader multi-country framework which can be utilized through the existing regional organizations and international organizations might be expected to lead to greater cooperation in the energy sector. This possibility is the springboard for the present research. In this thesis, I identify the key regional energy cooperative mechanisms employed by SSA regional organizations and ask whether these are efficient for tackling the challenge of energy access. The primary contribution of this work is to establish and propose a new method which could be employed by SSA regional bodies in both regulatory and infrastructural energy cooperative mechanisms to ensure that regional efforts are enhanced at the national level to tackle energy access and climate change challenges. I also propose a new definition of energy access which could be employed by regional and international organizations. This is much more than a matter of improving stipulative definitions: it is intended to contribute positively to an ongoing debate on the meaning of energy access and what such access entails.