<p>This thesis considers the effect of a large scale wind power introduction into an electricity system and the focus has been on the carbon dioxide emissions. Two different systems were studied, the Swedish and the Danish electricity system. When studying the Swedish electricity system different scenarios were created to see what might happen with the CO₂ emissions with an introduction of a large amount of wind power. The model that was used is based on parameters such as regulating power, transmission capacity, export possibility, and the electricity generation mixes in the Nordic countries. Given that the transmission capacity is good enough, the conclusion is that the carbon dioxide emissions will be reduced with a large scale introduction of wind power. In the Danish electricity system wind power is already introduced to a large extent. The main purpose here was to investigate the development of the CO₂ emissions and if it is possible to decide the actual change in carbon dioxide emissions due to the large scale introduction of wind power. The conclusions to this part are that the CO₂ emissions per kWh produced electricity have decreased since the electricity generation mix has changed but the total amount of CO₂ emissions fluctuates depending on weather, in a dry year less hydro power from Norway and Sweden can be used and more electricity from the fossil fuelled CHPs are generated. It has not been possible to determine the influence of the wind power on the CO₂ emissions.</p>

This thesis considers the effect of a large scale wind power introduction into an electricity system and the focus has been on the carbon dioxide emissions. Two different systems were studied, the Swedish and the Danish electricity system. When studying the Swedish electricity system different scenarios were created to see what might happen with the CO2 emissions with an introduction of a large amount of wind power. The model that was used is based on parameters such as regulating power, transmission capacity, export possibility, and the electricity generation mixes in the Nordic countries. Given that the transmission capacity is good enough, the conclusion is that the carbon dioxide emissions will be reduced with a large scale introduction of wind power. In the Danish electricity system wind power is already introduced to a large extent. The main purpose here was to investigate the development of the CO2 emissions and if it is possible to decide the actual change in carbon dioxide emissions due to the large scale introduction of wind power. The conclusions to this part are that the CO2 emissions per kWh produced electricity have decreased since the electricity generation mix has changed but the total amount of CO2 emissions fluctuates depending on weather, in a dry year less hydro power from Norway and Sweden can be used and more electricity from the fossil fuelled CHPs are generated. It has not been possible to determine the influence of the wind power on the CO2 emissions.

The thesis investigates the application of ice thermal storage technology to situations where the price of electricity varies continuously with instantaneous network demand. A central hypothesis is postulated in chapter 1, which states: "A variable electricity pricing structure, in which unit price continuously varies in response to instantaneous network demand, enhances the opportunities and benefits of ice thermal storage. The benefits both financial and environmental are dependent on the establishment of control and design strategies which optimise performance by matching refrigeration load with the instantaneous electricity price. " For ease of reference, the form of pricing described above is referred to in the thesis as 'real time' electricity pricing. The 'pool price' which is used to facilitate the competitive electricity awkct in England and Wales, is one of the foremost examples of real time pricing. The thesis therefore uses the electricity supply industry in the UK as its research vehicle. Notwithstanding this, the work contained in the thesis can be applied to any country which applies real time electricity pricing mechanisms. The validity of the hypothesis is assessed in the thesis through the development of a variety of numerical and computer models. These models fall into two distinct categories; those concerned with predicting and optimising the financial benefits of ice thermal storage, and those concerned with predicting and optimising the environmental benefits of ice thermal storage. Chapters 2,3 and 4 should be treated as support chapters, which equip the reader with the prerequisite knowledge necessary to understand the research work contained in the later chapters. As such, these chapters contain, respectively, a description of the electricity supply industry in the UK, a discussion of demand side management in the UK, and a description of the technology involved in ice thermal storage. The parametric study contained in chapter 4 is however an original piece of research work by the author. The models developed to evaluate and optimise the economic benefits of ice thermal storage are presented in chapters 5 and 6, and are applied to contrasting theoretical case study applications, namely an office building and a dairy. In chapter 5a 'long hand' numerical analysis technique is used. In chapter 6 this technique is rationalised and developed into a computer model for optimising both the design and control of ice storage installations in real time electricity pricing applications. The environmental studies are presented in chapter 7. These concentrate on the ability of ice thermal storage to reduce carbon dioxide emissions. Although the overall objective of the chapter is to evaluate the carbon dioxide emissions associated with ice thermal storage, the bulk of the chapter is concerned with the development of a model for predicting the carbon dioxide emissions per kWh of delivered electrical energy in England and Wales on a time related basis. The development of this 'time of day' carbon dioxide model is one of the main objectives of the thesis. Having established this model, it is then used to analyse the carbon dioxide emissions associated with the dairy case study.

<p>This paper investigates the environmental effectiveness of the Swedish energy taxes. That is, whether these have decreased the CO2 emissions and how they have changed the structure of the energy consumption. Time series data for the years 1960-2002 is used. The results show that the oil and coal taxes seem to favour a substitution towards less CO2 intensive energy sources. For the natural gas tax however, the opposite is true. An energy saving effect is found for the oil tax and the petrol tax, but the electricity tax seems to increase energy consumption. Regarding the total effect on CO2 emissions, the oil and coal taxes seem to decrease CO2 emissions while the natural gas tax seems to increase them.</p><p>Cross-country regressions are also made to examine if countries with a higher petrol tax have lower a lower rate of CO2 emissions on average. The results show that a higher petrol tax is significantly correlated to lower CO2 emissions.</p><p>The results thus indicate that energy taxes do decrease CO2 emissions. They also show that caution should be used before implementing a natural gas tax since it can have adverse effects on the CO2 emissions.</p>

This paper investigates the environmental effectiveness of the Swedish energy taxes. That is, whether these have decreased the CO2 emissions and how they have changed the structure of the energy consumption. Time series data for the years 1960-2002 is used. The results show that the oil and coal taxes seem to favour a substitution towards less CO2 intensive energy sources. For the natural gas tax however, the opposite is true. An energy saving effect is found for the oil tax and the petrol tax, but the electricity tax seems to increase energy consumption. Regarding the total effect on CO2 emissions, the oil and coal taxes seem to decrease CO2 emissions while the natural gas tax seems to increase them. Cross-country regressions are also made to examine if countries with a higher petrol tax have lower a lower rate of CO2 emissions on average. The results show that a higher petrol tax is significantly correlated to lower CO2 emissions. The results thus indicate that energy taxes do decrease CO2 emissions. They also show that caution should be used before implementing a natural gas tax since it can have adverse effects on the CO2 emissions.

This dissertation examines three facets of U.S. energy use and policy. First, I examine the Gulf Coast petroleum refining industry to determine the structure of the industry. Using the duality between cost-minimization and production functions, I estimate the demand for labor to determine the underlying production function. The results indicate that refineries have become more capital intensive due to the relative price increase of labor. The industry has consolidated in response to higher labor costs and costs of environmental compliance. Next, I examine oil production in the United States. An empirical model based on the theoretical framework of Pindyck is used to estimate production. This model differs from previous research by using state level data rather than national level data. The results indicate that the production elasticity with respect to reserves and the price elasticity of supply are both inelastic in the long run. The implication of these findings is that policies designed to increase domestic production through subsidies, tax breaks, or royalty reductions will likely provide little additional oil. We simulate production under three scenarios. In the most extreme scenario, prices double between 2005 and 2030 while reserves increase by 50%. Under this scenario, oil production in 2030 is approximately the same as the 2005 level. The third essay estimates demand for fossil fuels in the U.S. and uses these estimates to forecast CO2 emissions. The results indicate that there is almost no substitution from one fossil fuel to another and that all three fossil fuels are inelastic in the long run. Additionally, all three fuels respond differently to changes in GDP. The result of the differing elasticities with respect to GDP is that the energy mix has changed over time. The implication for forecasting CO2 emissions is that models that cannot distinguish changes in the energy mix are not effective in forecasting CO2 emissions.

Anthropogenic CO₂ captured from a coal-fired power plant can be used for an enhanced oil recovery (EOR) operation while mitigating the atmospheric impact of CO₂ emissions. Concern about climate change caused by CO₂ emissions has increased the motivation to develop carbon capture and sequestration (CCS) projects to reduce the atmospheric impact of coal and other fossil fuel combustion. Enhanced oil recovery operations are typically constrained by the supply of CO₂, so there is interest from oil producers to use large-volume anthropogenic (LVA) CO₂ for tertiary oil production. The intermittency of LVA CO2 emissions creates an area of concern for both oil producers and electric utilities that may enter into a CO₂ supply contract for EOR. An oil producer wants to know if intermittency from a non-standard source of CO₂ will impact oil production from the large volume being captured. Since the electric utility must supply electricity on an as-needed basis, the CO₂ emissions are inherently intermittent on a daily and seasonal basis. The electric utility needs to know if the intermittent supply of CO₂ would reduce its value compared to CO₂ delivered to the oil field at a constant rate. This research creates an experimental test scenario where one coal-fired power plant captures 90% of its CO₂ emissions which is then delivered through a pipeline to an EOR operation. Using real emissions data from a coal-fired power plant and simplified data from an actual EOR reservoir, a series of reservoir simulations were done to address and analyze potential operational interference for an EOR operator injecting large-volume, intermittent CO₂ characteristic of emissions from a coal-fired power plant. The test case simulations in this study show no significant impact to oil production from CO₂ intermittency. Oil recovery, in terms of CO₂ injection, is observed to be a function of the total pore volumes injected. The more CO₂ that is injected, the more oil that is produced and the frequency or rate at which a given volume is injected does not impact net oil production. Anthropogenic CO₂ sources can eliminate CO₂ supply issues that constrain an EOR operation. By implementing this nearly unlimited supply of CO₂, oil production should increase compared to smaller-volume or water-alternating-gas (WAG) injection strategies used today. Mobility ratio and reservoir heterogeneity have a considerable impact on oil recovery. Prediction of CO₂ breakthrough at the production wells seems to be more accurate when derived from the mobility ratio between CO₂ and reservoir oil. The degree of heterogeneity within the reservoir has a more direct impact on oil recovery and sweep efficiency over time. The volume of CO₂ being injected can eventually invade lower permeability regions, reducing the impact of reservoir heterogeneity on oil recovery. This concept should mobilize a larger volume of oil than a conventional volume-limited or WAG injection strategy that may bypass or block these lower permeability regions. Besides oil recovery, a reservoir's performance in this study is defined by its CO₂ injectivity over time. Elevated injection pressures associated with the large-volume CO₂ source can substantially impact the ability for an oil reservoir to store LVA CO₂. As CO₂, a less viscous fluid, replaces produced oil and water, the average reservoir pressure slowly declines which improves injectivity. This gradual improvement in injectivity is mostly occupied by the increasing volume of recycled CO₂. Sweep efficiency is critical towards minimizing the impact of CO₂ recycling on reservoir storage potential. Deep, large, and permeable oil reservoirs are more capable of accepting LVA CO₂, with less risk of fracturing the reservoir or overlying confining unit. The depth of the reservoir will directly dictate the injection pressure threshold in the oil reservoir as the fracture pressure increases with depth. If EOR operations are designed to sequester all the CO₂ delivered to the field, additional injection capacity and design strategies are needed. / text

Deforestation contributes approximately 20 percent of global annual carbon dioxide (CO2) emissions. Increased CO2 is thought to contribute to increased global temperatures. Proposals have been brought forward to use carbon finance to compensate developing countries for reducing emissions from deforestation and degradation (REDD). International negotiations at the UN Climate Change Convention in Copenhagen in December 2009 will determine if REDD Offsets will be included in a post-Kyoto Protocol framework. At the time of writing, Canada proposes to achieve a 20 percent reduction in greenhouse emissions below 2006 levels by 2020 through an intensity based cap-and-trade scheme. International forestry-based offsets are specifically excluded from the proposed Canadian regulatory scheme. The international demand for REDD Offsets will likely grow with acceptance under the proposed US scheme, and others. With proper regulations, international REDD Offsets could be included in the proposed Canadian regulatory system providing benefit to regulated entities and the developing world.

Given the energy intensive nature of the South African economy and the country’s dependence on fossil fuels, the reduction of greenhouse gas (GHG) emissions poses a serious problem to poverty alleviation, economic growth and employment. This study assesses the inter-industry and macro-economic impacts of carbon dioxide emissions reduction in South Africa. A monetary energy input-output table was developed using data from supply and use tables and a physical energy-emissions input-output table was developed from the national energy balance and the country’s GHG inventory. Both tables were used to develop the energy-emissions input-output model. Carbon dioxide taxes and energy subsidy reform were selected as potential economic policy instruments for analysis in South Africa. The energy-emissions input-output model was used to analyse the implications of the selected policy scenarios in terms of their effect on gross domestic product (GDP), employment, household consumption, energy consumption and energy emissions reduction. According to the energy-emissions input-output model developed in this study, financial and community services, construction and accommodation and machinery and equipment have the largest final demand and value added while nuclear energy, natural gas and biomass have the smallest final demand and value added. Renewable energy is labour intensive but not energy intensive as this energy sector has the highest labour to value added and the lowest energy to labour and energy to value added ratios. The petroleum products sector is the least labour intensive and the most energy intensive as it has a low labour to value added ratio and high energy to labour and energy to value added ratios. For every one unit increase in biomass, renewable energy and nuclear energy results in the largest increase in output, income and employment while machinery and equipment, natural gas and gold and other mining sectors have the lowest increase in simple and total output, income and employment multipliers. There is not much movement between natural gas, nuclear energy, renewable energy and biomass and the rest of the economy. Coal and crude oil have a relatively moderate impact and are moderately impacted on by other industries in the economy. Although almost all other industries in the economy depend heavily on electricity and petroleum products, these two industries are not as heavily dependent on other industries. Coal is responsible for the largest direct primary energy emissions followed by crude oil while natural gas; nuclear energy, renewable energy and biomass have a low direct impact. The electricity sector accounts for the highest indirect impact on coal emissions and petroleum products have the highest indirect impact on crude oil emissions. The petroleum products sector has the highest indirect impact on natural gas emissions. The electricity sector is largely responsible for the direct impact on coal emissions in terms of total economic output and the petroleum products sector accounts for all crude oil emissions from output. Natural gas, renewable energy, nuclear energy and biomass have no effect on direct emission output ratio. The iron and metals sector has the largest direct impact on electricity emissions per output and transport and communication has the highest direct impact on petroleum products emission per output. The largest indirect coal pollution per output impact is in the electricity sector, followed by petroleum products and iron and metals, while machinery and equipment has the smallest indirect impact on coal emissions per output. Petroleum products have the largest indirect crude oil pollution per output and the petroleum products sector is the only sector with an indirect impact on natural gas emissions per output. The iron and metals sector has the largest indirect electricity emission per output followed by household consumption and financial and community services while natural gas has the smallest indirect electricity emissions per output followed by machinery and equipment. Nuclear energy, renewable energy and biomass have no indirect petroleum products emissions per output. Machinery and equipment and crude oil have the lowest indirect petroleum products emissions per output. Inter-industry analysis indicates that the tax on coal results in the largest decrease in total output in the electricity and petroleum products sectors while output in the petroleum products and gold and other mining sectors decreases the most with the tax on oil. The tax on electricity has the largest negative impact on the iron and metals and financial and community services sectors and the tax on petroleum products results in the largest decrease in the transport and communication and financial and community services sectors. The electricity and coal mining sectors suffer the largest decrease in output as a result of energy subsidy reform. Macro-economic impacts were analysed according to real and marginal decreases. Real changes were used to assess the impact of each policy in terms of direct changes to each specific variable. Marginal decreases were calculated as a ratio of decreasing GDP for each variable hence marginal employment equals change in employment as a ratio of change in GDP and marginal household consumption equals change in household consumption as change a ratio of change in GDP. Marginal excess burden of taxes was calculated as changes in tax revenue, as a ratio of decrease in GDP. In terms of decreasing GDP, employment and household consumption, the lower the marginal burden the better the policy. Although the tax on coal offers the highest reduction in real energy emissions, this scenario also results in the highest reduction in GDP, employment and household consumption. Therefore the coal tax is not considered as the best option for carbon dioxide emissions reduction in South Africa. The electricity tax offers a moderate reduction in real energy emissions, GDP, employment and household consumption. It is concluded that the electricity tax could be an option for carbon dioxide emissions reduction in South Africa. However energy subsidy reform offers higher energy emissions reduction and a moderate reduction in GDP, employment and household consumption. This scenario is recognised as the most efficient option for carbon dioxide reduction in South Africa in terms of real changes. The tax on coal indicates high marginal decreases in employment and household consumption, moderate marginal tax revenue and moderate marginal decrease in energy consumption and energy emissions reduction. The tax on crude oil indicates low marginal decreases in employment and household consumption, low marginal excess burden on taxes, low marginal decrease in energy consumption and a moderate marginal decrease in energy emissions. The tax on petroleum products indicates low marginal decreases in employment and household consumption, low marginal excess burden on taxes and a high marginal decrease in energy consumption and energy emissions. Energy subsidy reform offers moderate marginal decreases in employment and household consumption, low marginal excess burden on taxes and a low marginal decrease in energy consumption and energy emissions. The comparison of marginal burdens of energy emissions reduction policies indicates that energy subsidy reform offers the best option as this scenario has moderate marginal decreases in employment and household consumption, low marginal excess burden on taxes and a low marginal decrease in energy consumption and energy emissions. The tax on crude oil is selected as the second best alternative as this scenario has low marginal decreases in employment and household consumption, low marginal excess burden on taxes, low marginal decrease in energy consumption and a moderate marginal decrease in energy emissions. Therefore in terms of real and marginal reduction in energy emissions, energy consumption, GDP, employment and household consumption, energy subsidy reform proves to be the best policy instrument in terms of energy emissions reduction, energy consumption, poverty alleviation, economic growth and employment. / Thesis (PhD)--University of Pretoria, 2008. / Agricultural Economics, Extension and Rural Development / unrestricted

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