Economic and environmental analysis of standard, high efficiency, rainwater flushed, and composting toilets

The current sanitation technology in developed countries is based on diluting human excreta with large volumes of centrally provided potable water. This approach is a poor use of water resources and is also inefficient, expensive, and energy intensive. The goal of this study was to compare the standard sanitation technology (Scenario 1) with alternative technologies that require less or no potable water use in toilets. The alternative technologies considered were high efficiency toilets flushed with potable water (Scenario 2), standard toilets flushed with rainwater (Scenario 3), high efficiency toilets flushed with rainwater (Scenario 4), and composting toilets (Scenario 5). Cost, energy, and carbon implications of these five design scenarios were studied using two existing University of Toledo buildings. The results showed that alternative systems modeled in Scenarios 2, 4, and 5 were viable options both from an investment and an environmental performance perspective. High efficiency fixtures that use potable water (Scenario 2) is often the most preferred method in high efficiency buildings due to reduced water use and associated reductions in annual water and wastewater costs. However, the cost, energy, and CO(2)EE analyses all showed that Scenarios 4 and 5 were preferable over Scenario 2. Cost payback periods of scenarios 2, 4 and 5 were less than 10 years; in the future, increase in water and wastewater services would further decrease the payback periods. The centralized water and wastewater services have high carbon footprints; therefore if carbon footprint reduction is a primary goal of a building complex, alternative technologies that require less potable water and generate less wastewater can largely reduce the carbon footprint. High efficiency fixtures flushed with rainwater (Scenario 4) and composting toilets (Scenario 5) required considerably less energy than direct energy demands of buildings. However, the annual carbon footprint of these technologies was comparable to the annual carbon footprint from space heating. Similarly, the carbon savings that could be achieved from Scenario 4 or 5 were comparable to a recycling program that can be implemented in buildings.     

Innovative Approach to Financing Energy Conservation Investments in Developing Countries

A common barrier to undertaking conservation measures in developing countries is the limited ability or the reluctance of energy users to acquire and deploy the capital needed to develop these opportunities. Industrial firms, for example, have had frequent opportunities in recent years to benefit from the use of new, more energy-efficient production technologies, but insufficient internal cash, combined with an ability to raise debt or equity capital under favourable terms, have often prevented firms from funding these investments.
Confronted with such impediments to mobilizing capital for conservation investments, some financiers and entrepreneurs in industrialized countries have recently implemented five innovative arrangements for financing conservation and other energy-related investments. These five financing arrangements are discussed. For each arrangement, the structure and operation, the distribution of risk between the energy user and the creditors/external investors, and the financial benefits that accrue to the energy user are described.     

Greenhouse gas Emissions projections and mitigation options for the Czech Republic, 1990–2010

The models used to assess greenhouse gas mitigation options for the Czech Republic are discussed and compared with respect to their capabilities and ease of use. The input data and preliminary results are described. According to the projections, Czech CO₂ emissions will not exceed their 1990 level until 2010. Assessment of several mitigation options shows that a 6% reduction in CO₂ emissions can be achieved using cost-effective technologies. Key areas for mitigation measures are fuel switching from brown coal to natural gas through replacement of boilers, efficiency improvements in household heating, and use of compact fluorescent lamps.     

Assessing energy efficiencies and greenhouse gas emissions under bioethanol-oriented paddy rice production in northern Japan

To establish energetically and environmentally viable paddy rice-based bioethanol production systems in northern Japan, it is important to implement appropriately selected agronomic practice options during the rice cultivation step. In this context, effects of rice variety (conventional vs. high-yielding) and rice straw management (return to vs. removal from the paddy field) on energy inputs from fuels and consumption of materials, greenhouse gas emissions (fuel and material consumption-derived CO(2) emissions as well as paddy soil CH(4) and N(2)O emissions) and ethanol yields were assessed. The estimated ethanol yield from the high-yielding rice variety, "Kita-aoba" was 2.94 kL ha(-1), a 32% increase from the conventional rice variety, "Kirara 397". Under conventional rice production in northern Japan (conventional rice variety and straw returned to the paddy), raising seedlings, mechanical field operations, transportation of harvested unhulled brown rice and consumption of materials (seeds, fertilizers, biocides and agricultural machinery) amounted to 28.5 GJ ha(-1) in energy inputs. The total energy input was increased by 14% by using the high-yielding variety and straw removal, owing to increased requirements for fuels in harvesting and transporting harvested rice as well as in collecting, loading and transporting rice straw. In terms of energy efficiency, the variation among rice variety and straw management scenarios regarding rice varieties and rice straw management was small (28.5-32.6 GJ ha(-1) or 10.1-14.0 MJ L(-1)). Meanwhile, CO(2)-equivalent greenhouse gas emissions varied considerably from scenario to scenario, as straw management had significant impacts on CH(4) emissions from paddy soils. When rice straw was incorporated into the soil, total CO(2)-equivalent greenhouse gas emissions for "Kirara 397" and "Kita-aoba" were 25.5 and 28.2 Mg CO(2) ha(-1), respectively; however, these emissions were reduced notably for the two varieties when rice straw was removed from the paddy fields in an effort to mitigate CH(4) emissions. Thus, rice straw removal avers itself a key practice with respect to lessening the impacts of greenhouse gas emissions in paddy rice-based ethanol production systems in northern Japan. More crucially, the rice straw removed is available for ethanol production and generation of heat energy with a biomass boiler, all elements required for biomass-to-ethanol transformation steps including saccharification, fermentation and distillation. This indicates opportunities for further improvement in energy efficiency and reductions in greenhouse gas emissions under whole rice plant-based bioethanol production systems.     

Greenhouse gas Emissions projections and mitigation options for the Czech Republic, 1990–2010

The models used to assess greenhouse gas mitigation options for the Czech Republic are discussed and compared with respect to their capabilities and ease of use. The input data and preliminary results are described. According to the projections, Czech CO₂ emissions will not exceed their 1990 level until 2010. Assessment of several mitigation options shows that a 6% reduction in CO₂ emissions can be achieved using cost-effective technologies. Key areas for mitigation measures are fuel switching from brown coal to natural gas through replacement of boilers, efficiency improvements in household heating, and use of compact fluorescent lamps.

     

新型固硫节煤剂在供热锅炉系统中的应用

长庆油田矿区服务事业部各生活小区锅炉90%的能源用于小区采暖供热,锅炉供热能耗大,效率低。为降低供热能耗,2012年1月对庆城基地锅炉系统中的SZL14--1.0/95/70型号锅炉使用固硫节煤剂的应用效果进行了现场试验对比。试验证明:通过添加新型固硫节煤剂能改善炉膛燃烧氛围、促进燃烧完全,降低炉渣含碳量,提高热效率7%,节煤率12%。同时,固硫效果明显,烟尘排放CO、SO2明显减少。     

WOOD ENERGY AND RURAL COMMUNITIES

Woodfuels (firewood and charcoal) comprise the predominant source of energy for rural populations in developing countries, and are likely to continue to do so. Increasing depletion of locally available wood supplies can lead to reductions in energy available for cooking and heating, increasing diversion of agricultural residues to fuel use, and deterioration of physical environments dependent on tree cover. This paper examines different ways of dealing with the problem and argues that attention must be paid to means of alleviating demand for woodfuels in the short term by using existing supplies more efficiently, as well as to increasing their supply over the longer term.     

Causes of energy poverty in a cold and resource-rich country: evidence from Kazakhstan

Kazakhstan is an upper-middle-income country and one of the coldest countries in the world with rich energy resources and energy prices considerably lower than in developed countries. This paper presents the first comprehensive overview of household fuel use in Kazakhstan and assesses the causes and extent of energy poverty using the Households Living Conditions Survey dataset of 12,000 households. The results show that there is an overwhelming reliance on coal in Kazakhstan: 40% of all surveyed households use coal for heating, cooking and other needs. In general, liquefied petroleum gas is mainly used for cooking, coal and firewood for heating, while electricity is rarely used for heating. Energy poverty was less prevalent in oil and gas rich regions, due to low gas prices and higher income levels in those regions, while households located in the North Kazakhstan, Central and East Kazakhstan mainly suffer from lack of cleaner fuel options, income poverty, longer and colder winters and consequently energy affordability. Despite low energy prices in Kazakhstan, the results demonstrate that 28% of surveyed households spend more than 10% of their income on energy. Gas and district heating infrastructure coverage and income inequality across its regions contributed the most to energy poverty in Kazakhstan. Energy prices are regulated and indirectly subsidised. Removing energy subsidies alone may worsen energy affordability of households. Offering direct subsidies to cover part of the energy expenditures may not fully solve the problem, but subsidies, interventions for efficient technologies and fuels, dwelling energy-efficiency improvements are necessary.     

Energy Considerations in Design for Environment: Appropriate Energy Selection and Energy Efficiency

Abstract

The design aspects of energy selection and energy efficiency are described. These topics are key components of Design for Environment, and thus are important considerations in industrial ecology. In the article, background material is presented on energy forms, sources, carriers and conversion technologies. Then, energy use in countries, regions and sectors is discussed, and the impact of energy use on the environment described. Efficiencies and other measures of merit for energy use are presented, and design for energy selection and for energy efficiency are described, highlighting energy-related design factors for pollution prevention. Finally sustainable development and its relation to energy and efficiency are discussed, and a case study is presented.     

Making a stronger case for industrial energy efficiency by quantifying non-energy benefits

This paper describes a more compelling case for industry to promote the non-energy benefits of energy efficiency investments. We do this in two ways to actively appeal to chief executive officers (CEOs) and chief financial officers (CFOs) primary responsibility: to enhance shareholder value. First, we describe the use of a project-by-project corporate financial analysis approach to quantify a broader range of productivity benefits that stem from investments in energy-efficient technologies, including waste reduction and pollution prevention. Second, and perhaps just as important, we present such information in corporate financial terms. These standard, widely-accepted analysis procedures are more credible to industry than the economic modeling done in the past because they are structured in the same way corporate financial analysts perform discounted cashflow investment analyses on individual projects. Case studies including such financial analyses, which quantify both energy and non-energy benefits from investments in energy-efficient technologies, are presented. Experience shows that energy efficiency projects’ non-energy benefits often exceed the value of energy savings, so energy savings should be viewed more correctly as part of the total benefits, rather than the focus of the results. Quantifying the total benefits of energy efficiency projects helps companies understand the financial opportunities of investments in energy-efficient technologies. Making a case for investing in energy-efficient technologies based on energy savings alone has not always proven successful. Evidence suggests, however, that industrial decision makers will understand energy efficiency investments as part of a broader set of parameters that affect company productivity and profitability.     

IMPACTS OF WATER USE EFFICIENCY ON ENERGY DEVELOPMENT1

ABSTRACT: To help meet national energy demands, interest has been focused on the coal, oil shale, and uranium deposits of the Upper Colorado River Basin. Several energy output projections for the basin have been presented based upon water availability. Inherent in all these analyses are estimates as to the rate of water use in each energy development. New energy technologies are characterized by parameters extrapolated from small scale energy facilities. The data provide projected costs, conversion efficiencies, and material inputs and outputs. Alternative techniques for process cooling and solids handling provide variable rates of water use which affect other conversion parameters. Results from a mathematical model are used in analyzing the sensitivity of an optimal energy development strategy for the Upper Colorado River Basin. The impacts of alternative water use rates are investigated in terms of net energy output, total cost, and displacements in the development strategy. Similarly, controls and regulations on energy resource development are evaluated.     

Estimating the Relative Efficiency of Brazilian Publicly and Privately Owned Water Utilities: A Stochastic Cost Frontier Approach1

Abstract: This paper assesses cost efficiencies of Brazilian public and private companies of water supply. To measure the efficiency, we used a stochastic frontier model derived from the translog family – a specification similar to a Cobb‐Douglas including a quadratic term in log output. The model parameters are estimated by maximum likelihood using Brazilian data for the year 2002. Statistical inference leads to the conclusion that there is no evidence that private firms and public firms are significantly different in terms of efficiency measurements.     

Performance assessment of integrated energy systems for HVAC applications

In this article, energy and exergy analyses are conducted for two integrated systems which can be used in HVAC applications. These two systems are analyzed for the cases of single generation, cogeneration and trigeneration, and their performances are evaluated through energy and exergy efficiencies. The parametric studies are performed to investigate the effects of using cogeneration and extended to trigeneration on the system performance. To perform the comparisons between the systems for multiple options, the same amounts of outputs (in terms of electricity, heating, cooling) are produced for all systems. The energy analyses of systems 1 and 2 show a great benefit for moving from single generation to trigeneration, with the trigeneration efficiencies of 83.5% and 87.2%, respectively, and single generation efficiencies of 47% for both systems. However, the exergy analyses show that trigeneration may not always become more efficient than single generation, particularly for system 1, due to the fact that the trigeneration exergy efficiency is 38.7% and the corresponding single generation efficiency is 44.3%. For system 2, the trigeneration exergy efficiency is 52.7% while the single generation efficiency becomes 44.3%. Depending on the type of cogeneration or cogeneration design, the system can be more efficient.     

Devising an integrated methodology for analyzing energy use and CO2 emissions from Taiwan's petrochemical industries

Input-output modeling and multiplier analysis are used to assess Taiwan's five petrochemical industries, based upon their economic contribution and potential impacts on energy consumption and CO2 emission. In addition, a consolidated index system was developed for evaluating energy and economic efficiencies as well as targets for CO2 reduction. Results indicate that petrochemical materials (PM) make a major contribution to economic development, with lesser contributions from plastic materials (PL) and artificial fibres (AF). PM has the highest energy multiplier while PL has the largest induced potential for energy consumption. Plastic and rubber products (PP, RP) are relatively insignificant energy consumers. AF has the highest CO2 multiplier, and its induced potential for CO2 emission is the most significant. The consolidated index shows that the upstream petrochemical industries perform rather poorly in an integrated view of economic, energy, and CO2 emission, and should be seen as the primary targets for CO2 reduction. Investment of the petrochemical industries in Taiwan should be adjusted to improve energy efficiency, economic bases, and lower CO2 emissions.     

The Prospects for Improved Energy Efficiency in the UK Residential Sector

The perceived threat of climate change has become an important global issue of the 1990s, with measures to limit its ramifications now commonly linked to mainstream policy agendas. Reducing carbon intensity can be achieved through both supply and end-use energy strategies, though improvements in end-use efficiency are said to offer the best opportunities both in terms of effective investment and producing results in the short to medium term. UK policy makers have stressed that energy use in the home is a pressing area to be addressed. This paper reviews the myriad of efficiency options available, assessing the effectiveness of national and supra-national strategies in encouraging technical efficiency and stimulating beneficial behaviourial changes. Findings indicate that the range of (and commitment to) current efficiency measures, reinforced by a lack of policy coherence, ensures that future prospects remain ambiguous. Initiatives, though conceived at a variety of spatial scales, tend to be implemented at a localized level and it is the actions (and interactions) of local actors that may well determine the shape and success of sustainability measures.     

Energy efficiency: The best immediate option for a secure, clean, healthy future

The imperatives for reducing the world's dependence on fossil and nuclear fuels have multiplied manifold in recent years with the advent of worldwide terrorism. These new dangers come in addition to the imperatives of addressing the dire consequences of global warming and devastating pollution that accompany the use of these fossil fuels. Reducing dependence on these unsafe and unreliable energy resources should be a top global priority. Implementation of proven energy efficiency technologies offers the world the fastest, safest, most economic and most environmentally benign way to alleviate these threats. This article outlines available efficiency measures, their economic advantages and means by which they may be and have been implemented. While examples of efficiency applications from both developed and developing countries are given, the article relies heavily on experience with energy efficiency in the United States, where data on efficiency is particularly abundant.     

Problems and Prospects of Meeting the Basic Energy Needs of Rural Communities in Developing Countries Through the Utilization of Wind and Solar Energy Systems

The problems and prospects of solar and wind energy technologies for rural energy supply in developing countries are examined, followed by an overview of key attributes of these technologies. The application of wind and solar systems for cooking, water pumping, drying, water heating, and electric power supply are reviewed. Two detailed case studies are given, the first discussing the potential of solar and wind systems for rural water pumping in Morocco, and the second, examining the "wind farms" producing electric power in California and the potential for their use in developing countries.     

Energy,exergy analysis,and sustainability assessment of different engine powers for helicopter engines

The rapid decrease of energy resources has accelerated studies on energy efficiency. Energy efficiency refers to the effective use of energy, in other words, completing a specific task to the required standard by using less energy. Exergy is an effective instrument to indicate the effective and sustainable use of energy in systems and processes. Transportation is an important part of human life. The studies on energy saving and the effective use of energy in different areas around the world have also increased for transportation systems and vehicles. With the more effective use of fuel, there will be potential benefits for the environment as well as a reduction in operating costs. This study includes energy and exergy analyses as well as a sustainability assessment by using C₈H₁₆ as a fuel at different engine powers (150–600 SHP (shaft horse power)), for the piston-prop helicopter engine. The maximum exergetic sustainability index was found at the power that provided the maximum energy and exergy efficiency. As a result of this index, the lowest waste exergy ratio, the lowest exergy destruction factor, and the lowest environmental impact factor were obtained. The highest exergy destruction and the highest exergy loss value were obtained at maximum power (600 SHP).     

Evaluating the prospects for sustainable energy development in a sample of Chinese villages

This paper describes the methods used to evaluate the potential for achieving sustainable energy development in six Chinese villages included in the Sustainable Users' Concepts for China Engaging Scientific Scenarios (SUCCESS) Project by examining energy efficiency potential and local renewable energy prospects. The approaches needed to obtain and analyse information on possible energy efficiency measures and renewable energy resources are summarised. Results are presented in terms of cumulative net savings in primary energy consumption, as an indicator of energy resource depletion, and associated carbon dioxide emissions, as an indicator of global climate change. Options for sustainable energy development are ranked in order of likely implementation and practical actions which could be considered in each village are identified.     

The phosphorus footprint of China's food chain: implications for food security, natural resource management, and environmental quality

Efficient use of phosphorus (P) for producing food, preventing water pollution, and managing a dwindling rock P reserve are major challenges for China. We analyzed P stocks and flows in the Chinese food chain to identify where P use efficiency can be improved, where P leaks to the environment, and the research, technologies, and policies needed to improve P use. We found a high degree of inefficiency; of 6652 Gg P entering the food chain, only 1102 Gg P (18%) exit as food for humans. The greatest inefficiencies were a large build-up of soil P (3670 Gg P yr; 52% of P inputs) and high P losses to the environment from animal production (1582 Gg P yr; 60% of excreted P). Improving P use in China must focus on national-scale nutrient management strategies, better animal nutrition, and adoption of technologies and policies to reduce P discharges from the animal sector and recycle P as manures in agriculture.