Global Environment Facility investments in the phase-out of ozone-depleting substances

Stratospheric ozone depletion threatens human health and the global environment. In 1987, the Montreal Protocol on Substances That Deplete the Ozone Layer (Montreal Protocol) set aggressive timelines for countries to phase-out products and organic chemicals that were causing rapid ozone depletion in the Antarctic stratosphere. The Global Environment Facility (GEF), established in 1991, is the largest multilateral funder of environmental protection projects and provides financial support for implementation of the Montreal Protocol. This paper summarizes GEF investments to address ozone-depleting substances (ODS) in Countries with Economies in Transition (CEITs), presents case studies from representative countries, and discusses lessons learned. Complementing the work of the Multilateral Fund that supports developing country Parties of the Montreal Protocol, the GEF provides financial support to CEIT’s to address ODS phase-out targets and timelines. These investments include technology development and transfer, outreach and training, institution building, and programs to phase-out ODS. Working with partners in the public and private sectors, the GEF has allocated approximately US210 million, leveraging another US210 million, leveraging another US250 million in co-financing, for 28 ODS phase-out projects in 18 CEITs. GEF ODS project investments in CEITs have contributed to Protocol success by phasing-out 20,000 ozone depletion potential (ODP) Megagrams (Mg) of consumption and 29,000 ODP Mg of production. Among the GEF’s most significant efforts to eliminate ODS are projects that transfer technologies and strengthen institutional capabilities of partner countries. These projects have enabled the installation of non-ODS technologies, adoption of best practices by the private sector, and provided CEITs with the legislative and policy framework necessary to sustain ODS phase-out. Almost 25 years after its establishment, the Montreal Protocol with support from financial mechanisms such as the GEF, is a successful model for addressing global environmental challenges.     

Clean Development Mechanism Potential and Challenges in Sub-Saharan Africa

Sub-Saharan Africa lags far behind other regions in terms of the implementation of Clean Development Mechanism (CDM) projects due to several reasons. One of the reasons is a general perception that, since the region contributes very little to global GHG emissions, it also offers few opportunities to reduce these emissions. Using a bottom-up approach, this study investigates the technical potential of reducing GHG emissions from the energy sector in Sub-Saharan Africa through the CDM. The study finds that sub-Saharan Africa could develop 3,227 CDM projects, including 361 programs of activities, which could reduce approximately 9.8 billion tons of GHG emissions during the CDM project cycles. The study also estimates that the realization of this CDM potential could significantly enhance sustainable development in the region as it would attract more than US200 billion in investment and could generate US200 billion in investment and could generate US98 billion of CDM revenue at a CER price of US$10/tCO2. Another notable finding of the study is that the realization of this CDM potential could supply clean electricity by doubling the current capacity and thereby providing access of electricity to millions of people in the region. However, realization of this CDM potential is severely constrained by a number of financial, technical, regulatory and institutional barriers.     

Financing for innovative technologies and best practices to reduce persistent organic pollutants

Persistent Organic Pollutants (POPs) threaten human health and the global environment. Recognizing their dangers many countries began to limit or ban POPs production, use, and release in the 1990s. Eventually the Stockholm Convention on POPs, was adopted in 2001 and entered into force in 2004. The Global Environment Facility (GEF) provides financial support to developing country Parties for the implementation of the Stockholm Convention. The GEF’s POPs investment portfolio focuses on: 1) strengthening the capacity of developing country Parties to implement the Stockholm Convention; 2) establishing and supporting partnerships to develop and implement National Implementation Plans (NIPs), and 3) demonstrating and deploying best technologies and practices to reduce POPs emission, including development of safe alternatives. Since 2001 the GEF has committed US$568.8 million to POPs projects and leveraged some US$1474.5 million in co-financing from partners in the public and private sectors, bringing the total value of the GEF POPs portfolio to over US$2 billion. With GEF support, 108 developing country Parties have developed their NIPs. The GEF also financed 109 projects for the implementation of the Convention. Upon completion, these GEF POPs investments will contribute to the disposal of more than 70,000 tons of Polychlorinated Biphenyls (PCBs) oil, contaminated equipments, and waste, more than 40,000 tons of obsolete POPs pesticides and associated waste, and reducing dioxin/furan and mercury emission by introducing environmentally sound technologies and best practices. This paper summarizes: 1) direct and indirect GEF investments to support the goals of the Stockholm Convention; 2) investment case studies on PCB, DichloroDiphenylTrichloroethane (DDT), chlordane and mirex, medical waste, obsolete POPs and engaging civil society; and 3) lessons learned in terms of GEF financing strategies, best technologies and environmental practices to address POPs.     

An executive review of sludge pretreatment by sonication

Ultrasonication (US), which creates hydro-mechanical shear forces in cavitation, is an advanced technology in sludge pretreatment. However, there are many factors affecting the efficacy of cavitation and ultrasonication disintegration of sludge as a consequence. The objective of this work is to present an extensive review of evaluation approaches of sludge US pretreatment efficiency. Besides, optimization methodologies of related parameters, the differences of optimum values and the similarities of affecting trends on cavitation and sludge pretreatment efficiency were specifically pointed out, including ambient conditions, ultrasonic properties, and sludge characteristics. The research is a prerequisite for optimization of sludge US pretreatment efficiency in lab-scale and practical application. There is not-yet a comprehensive method to evaluate the efficiency of sludge US pretreatment, but some main parameters commonly used for this purpose are degree of sludge disintegration, proteins, particle size reduction, etc. Regarding US parameters, power input P_US, intensity I_US, and frequency F_S seem to have significant effects. However, the magnitude of the effect of P_US and probe size in terms of I_US has not been clearly detailed. Investigating very low F_S seems interesting but has not yet been taken into consideration. In addition, static pressure effect has been marginally studied only and investigation on the effect of pH prior to US process has been restricted. Their effects therefore should be varied separately and simultaneously with other related parameters, i.e. process conditions, ultrasonic properties, and sludge characteristics, to optimize sludge US pretreatment process.     

Quantification of energy related industrial eco-efficiency of China

Improving eco-efficiency is propitious for saving resources and reducing emissions, and has become a popular route to sustainable development. We define two energy-related eco-efficiencies: energy efficiency (ENE) and greenhouse gas (GHG) emission-related eco-efficiency (GEE) using energy consumption and the associated GHG emissions as the environmental impacts. Using statistical data, we analyze China’s energy consumption and GHG emissions by industrial subsystem and sector, and estimate the ENE and GEE values for China in 2007 as 4.871×10⁷ US/PJ and 4.26×10 < sup > 8 < /sup > US/PJ and 4.26×10⁸ US/TgCO₂eq, respectively. Industry is the primary contributing subsystem of China’s economy, contributing 45.2% to the total economic production, using 79.6% of the energy consumed, and generating 91.4% of the total GHG emissions. We distinguish the individual contributions of the 39 industrial sectors to the national economy, overall energy consumption, and GHG emissions, and estimate their energyrelated eco-efficiencies. The results show that although ferrous metal production contributes only 3.5% to the national industrial economy, it consumes the most industrial energy (20% of total), contributes 16% to the total industrial global warming potential (GWP), and ranks third in GHG emissions. The power and heat sector ranks first in GHG emissions and contributes one-third of the total industrial GWP, although it only consumes about 8% of total industrial energy and, like ferrous metal production, contributes 3.5% to the national economy. The ENE of the ferrous metal and power and heat sectors are only 8 and 2.1×10⁷ US/PJ, while the GEE for these two sectors are 9 and 4×10 < sup > 4 < /sup > US/PJ, while the GEE for these two sectors are 9 and 4×10⁴ US/GgCO₂eq, respectively; these are nearly the lowest ENE and GEE values among all 39 industry sectors. Finally, we discuss the possibility of ecoefficiency improvement through a comparison with other countries.     

Co-benefits of a carbon tax in Nepal

This paper analyzes the co-benefits of introducing a time variant carbon (C) tax scheme in Nepal, a hydropower resourceful country, by using a bottom up integrated energy system model based on the MARKet ALlocation (MARKAL) framework with time horizon of 2005–2050. It discusses the effects of C tax on energy mix, environmental emissions, energy supply security, energy efficiency, energy system cost, and employment benefit. The study shows that the C tax (that gradually increases from US13/tCO < sub > 2 < /sub > e in 2015 to US 13/tCO₂e in 2015 to US 200/tCO₂e by 2050) results in a reduction of the cumulative emission of greenhouse gases by 83.9 million tons CO₂e (12%) as compared to that in the base case. With the introduction of the C tax, there would be a need for additional hydropower capacity of 945 MW by 2050 as compared to the capacity in the base case. The emission of local pollutants consisting of sulphur dioxide (SO₂), nitrogen oxides (NO_x) and non-methane volatile organic compound (NMVOC) in 2050 would be reduced by 12%, 7% and 1% respectively under the C tax scenario. Total amount of imported energy would decrease by 13%, which corresponds to a reduction in discounted net fuel import cost by 5% during the study period. Furthermore, the C tax would result in new employment generation of 151 thousand man-years associated with the additional hydropower capacity requirement.     

Energy service company and financial market development: experiences of the Global Environment Facility

Energy Service Companies (ESCOs) and the energy market for ESCO financing have been developing since 1976 when oil prices increased dramatically. ESCOs’ services cover projects in many energy areas, including energy extraction, power generation, energy conversion, transportation, power transmission, energy consumption, project financing, energy project audits, monitoring, and energy savings verification. In developing countries, there are many barriers in the energy market that are preventing ESCOs from developing. These barriers include lack of appropriate policy, financial mechanisms, and local capacities for ESCO development and management. Over the past 20 years, the Global Environment Facility (GEF) financed 39 ESCO projects in 25 countries and regions to remove these barriers. The results of these projects show that some countries, such as China, are very successful in ESCO development, but others are not. Different models of ESCOs in different financial markets in various countries are analyzed; and case studies are undertaken for China, India, Ukraine, and Brazil. This article concludes that, while developing financial markets for ESCOs, countries need to consider (1) initiating national government policy to stop energy subsidies and to reform energy pricing, (2) establishing a real, market based financial mechanism for ESCOs, (3) involving the private sector in project co-financing, (4) creating incentives to ESCOs in the market by investing part of government revenue from energy tax, and (5) incentivizing ESCOs by government corporate tax exemption.     

Opportunities to reduce greenhouse gas emissions from households in Nigeria

Efforts to mitigate climate threats should not exclude the household as the household is a major driver of greenhouse gas (GHG) emissions through its consumption patterns. This paper derives an emission index that could be used to estimate inventories of carbon dioxide (CO₂) emissions from kerosene combustion for lighting in Nigeria and also looks at the implications of solar pv lighting replacing kerosene lamp in Nigeria. Findings indicate that (1) average CO₂ emissions from kerosene combustion for lighting in Nigeria is about 0.06 kg per hour per lamp, which can be taken as the kerosene lamp CO₂ emission index for Nigeria. (2) about 3 × 10W_p solar pv will be required to replace a kerosene lamp, while about 0.124 tonnes of CO₂ will be avoided per lamp per year, operating at 6 h daily. At the national level, under the kerosene lamp replacement projection assumptions made, between 0.4 and 1.0 million tonnes of CO₂ will be avoided per year. The household investment required to owe a solar pv, including the capital cost of switching from kerosene lamp, is about US356, while the national capital investment outlay is between 1,138.265 and US356, while the national capital investment outlay is between 1,138.265 and US2,848 million. (3) Certified Emission Reduction (CER) units, assuming CO₂ is traded, will generate significant annual revenues on the order of 6.96 to almost US17.4 million per year, while earnings from unspent household kerosene fuel could amount to between 2,520 and US17.4 million per year, while earnings from unspent household kerosene fuel could amount to between 2,520 and US6,300 million over the life span of the solar pv. The micro-economic assessment carried out indicates the non-attractiveness of solar pv use at the household level, and (4) to promote solar pv use, both long and short term policy measures that aim at cost reduction were suggested. The paper concludes that, factoring the suggested measures into the climate, energy, and financial policy decision discourse in Nigeria could empower the households to play a significant role in achieving global CO₂ emission reduction, but at the local level.     

Climate change mitigation and international finance: the effectiveness of the Clean Development Mechanism and the Global Environment Facility in India and Brazil

This study analyzes the effectiveness and efficiency of the two principal United Nations (UN) climate change mitigation finance mechanisms, the Clean Development Mechanism (CDM) and the Global Environment Facility (GEF). The realised abatement and costs of the two mechanisms in India and Brazil (using data from 28 GEF and 233 CDM project documents) are compared with theoretical marginal abatement cost curves, based on bottom-up technology studies. We find that both mechanisms have focused on negative and low-cost abatement potential but still leave substantial theoretical potential in this cost range untapped. CDM has more effectively harvested abatement potential of industrial gases and methane emissions, whereas GEF has more successfully targeted demand-side energy efficiency (EE) and transport emission reduction opportunities. CDM has excelled at capturing abatement potential in areas with a limited understanding of abatement, highlighting the shortcomings of theoretical estimates (such as Marginal Abatement Cost Curves) and the benefits of a market mechanism. In some sectors and technologies (particularly renewable energy), the two mechanisms overlapped, which suggests a need for better coordination in the future.     

Climate extremes,location vulnerability and private costs of property protection in Southwestern Cameroon

This study contends that climatic events such as storms and floods may significantly impact on cost of protection through climate proofing of housing structures along the Atlantic coastal zone in the Southwest region of Cameroon. Household level protection is purposely examined on the rationale that current protective efforts constitute the building blocks for long-term adaptation. Examining the determinants of the cost of current protection stands good stead to better inform policy to promote future adaptation to climatic stress. Hence, from a research sample of 400 households, the study estimates a function that relates household-level protection costs to their characteristics. Sixty-four percent of the homes studied have been hit at least once by strong winds, and an average of 2 times in the last 5 years, and 36% of houses have once been hit by storm surge from the sea nearby. With an average monthly income of 120.000 FCFA (US285), the coastal residents spend on average 145,500 FCFA (US 285), the coastal residents spend on average 145,500 FCFA (US 346) in preparation against floods. The statistical estimates of the cost function reveal significant positive signs, implying that the experiences and location of homes within floodplain increases the cost of protection no matter the structural characteristics of the house. The study observes that the proximity to the coast and in flood plains significantly increases the cost of protection, and the ability to invest in preventive measures and climate proofing housing structures increase as individual income grows. The findings indicate the need for improvement of monitoring and forecasting systems for floods, intensification of awareness and proper urban planning. The policy implications are reinforced by the low incomes of most residents, as this calls for external assistance through transfer of planning skills, capital and public options to reinforce the resilience and choices made at the household level.     

GIS and rural electricity planning in Uganda

Sustainable development is literally fuelled by the energy sector. In Uganda, the electricity sector has experienced dramatic market liberation in recent years. This reform was centred around the unbundling of the main government utility, Uganda Electricity Board (UEB), a monopoly divided into three companies created to introduce competition into the market. Market reform has also led to the creation of a regulatory body and a rural electrification fund with the aim of subsidising rural electricity investments. Through a multi-sectoral programme financed by the World Bank and the Global Environment Facility (GEF), the Ministry of Energy is developing a Rural Electrification Master Plan to provide a more systematic tool for rural electricity investments. Unlike previous approaches, this plan is demand driven. This paper discusses the use of Geographic Information Systems (GIS) in the planning process for rural electrification. The aim is to identify patterns of demand and priority areas for investment. By creating a demand-side scenario, electricity can then be supplied to targeted areas. A cross-sectoral view is taken to examine the energy demand patterns using physical data and available country statistics, incorporated into a GIS master database. Based on geo-referenced data of population and existing infrastructure, the initial priority demand-side sectors targeted are education and health. An energy benefit point system is then applied to each sector based on local conditions and needs assessments. Their aggregated points then provide an indicator of energy demand distribution for electricity planning at district level. As a result of this preliminary work, specific areas could then be targeted for investment and optimised supply systems could be designed, which include off-grid renewable energy plants such as small-scale hydropower schemes.     

The value of energy efficiency programs for US residential and commercial buildings in a warmer world

US residential and commercial buildings were responsible for about 41 exajoules (EJ) of primary energy use per year in 2002, accounting for approximately 9% of the world fossil-fuel related anthropogenic carbon (C) emissions of 6.7 Gt that contribute to climate change. US Government-sponsored building energy efficiency research and implementation programs are focused on reducing energy consumption in US residential and commercial buildings and reducing these carbon (C) emissions. Although not specifically intended for adaptation to a warmer climate and less effective than under today’s cooler climate, these programs also could help reduce energy demand in a future warmer world. Warming scenarios projected by the United Nations Intergovernmental Panel on Climate Change (IPCC) in 2001 imply net overall decreases in both site energy and primary energy consumption in US residential and commercial buildings, largely because of the reduced need for heating. However, there would be as much as a 25% increase in building space cooling demand and a significant part of the increase could be offset by energy-efficiency improvements in buildings. Overall, in the US, buildings-related energy efficiency programs would reduce site energy consumption in buildings in the US by more than 2 EJ in 2020 and primary energy by more than 3.5 EJ, more than enough to offset the projected growth in cooling energy consumption due to climate change and growth in the US building stock. The savings would have an estimated annual net value at 2005 energy prices of between $45.0 and $47.3 billion to consumers.

Renewable energy resources and technologies in Nigeria: present situation, future prospects and policy framework

Nigeria is endowed with abundant energy resources, both conventional and renewable, whichprovide her with immense capacity to develop an effective national energy plan. However, introduction of renewable energyresources into the nation's energy mix have implications on itsenergy budget. The national energy supply system has been projected intothe future using MARKAL, a large scale linear optimization model.However, this model may not be absolutely representative of the highlynon-linear future of renewable energy. Results of the model reveal that under onlya least cost constraint, only large hydro power technology is the prominentcommercial renewable energy technology in the electricity supply mix of thecountry. Despite the immense solar energy potentials available, solar electricity generation is attractive only under severeCO2 emissions mitigation of the nation's energy supply system. Similarly, the penetration of small-scale hydro power technology in theelectricity supply mix is favoured only under CO₂ emissionsconstraints. Due to economy of scale, large hydropower technology takes the lion share of all the commercial renewableenergy resources share for electricity generation under any CO₂emissions constraint. These analyses reveal that some barriers exist to thedevelopment and penetration of renewable energy resources electricity production in Nigeria's energy supplysystem. Barriers and possible strategies to overcome them arediscussed. Intensive efforts and realistic approachtowards energy supply system in the country will have to be adopted inorder to adequately exploit renewable energy resources and technologiesfor economic growth and development.     

Forest carbon management,the greenhouse effect and electric utilities

Electric utilities in the US have initiated forestry projects to conserve energy and to offset carbon dioxide (CO₂) emissions. In 1995, 40 companies raised US$2.5 million to establish the non-profit UtiliTree Carbon Company which is now sponsoring eight projects representing a mix of rural tree planting, forest preservation, forest management and research efforts at both domestic (Arkansas, Louisiana, Mississippi, and Oregon) and international sites (Belize and Malaysia). The projects include extensive external verification. Such forestry projects — properly documented, monitored and verified — should be a component of domestic and international strategies to address greenhouse gas (GHG) emissions, due to GHG benefits, cost-effectiveness and many other environmental benefits (e.g., related to habitat, erosion and biodiversity). These projects on average are projected to manage CO₂ at a cost of about US $1 per ton. Experts have determined through a series of technical workshops and projects that GHG benefits can be accurately quantified for most types of forestry projects and, in fact, forestry projects in general present no greater challenges than energy-related projects. Near-term policy decision-making related to CO₂ management via forestry is discussed.     

Bioenergy and the CDM in the Emerging Market for Carbon Credits

This paper analyses the eligibility of different types of biomass energy projects in developing countries for funding under the Kyoto Protocol's Clean Development Mechanism and related funds. Specifically, GHG emission reductions through the replacement of non-renewable types of biomass with renewable energy, or the improvement of the efficiency of energy systems based on non-renewable biomass, is discussed in more detail, as it is currently difficult if not impossible for these to qualify as CDM projects under current rules. These problems are caused by the categorical exclusion of land-use from the CDM (with the exception of afforestation and reforestation projects). The paper offers some possible solutions for both small-scale and large-scale CDM projects. These limitations hold for a number of carbon funds. The paper covers of the major funds operated by the World Bank and that are already operational, to point out differences between existing funds in order to identify the best opportunities for different biomass sources and technologies. This systematic, comparative analysis covers the characteristics of the different funds in terms of eligible technologies, geographical foci, and size (targets and completed and ongoing transactions, CO₂ equivalents, project asset values). To provide the context for the analysis of the carbon funds, the regulatory drivers and frameworks influencing the demand side of the market are discussed. This first of its kind analysis for the specifics of the carbon market regarding bioenergy enables decision makers and project managers active or planning to become active in the area, to identify and target the most promising funds for their specific purposes.     

Towards sustainable development in Austria: renewable energy contributions

Besides energy conservation, theexploration of renewable energy sources, inparticular biomass and solar energy, arecentral aspects of the Austrian energypolicy, regarded as an optimal option forachieving CO₂-emission reductionobjectives.The market penetration of RenewableEnergy Technologies in the last twentyyears was supported by the AustrianEnergy Research Programme. The result ofsuccessful developments of biomass heating,solar thermal, solar electrical and windenergy technologies is the key for themarket development of these renewableenergy technologies.With the market penetration of renewableenergy technologies new business areas wereestablished and employment created.Today, some renewable energy technologiesin Austria have reached economiccompetitiveness. Some technologies notreached commercialisation, and need moredevelopment to improve efficiency,reliability and cost to become commercial.This would include material and systemdevelopment, pilot plants or fieldexperiments to clarify technical problems,and demonstration plants to illustrateperformance capabilities and to clarifyproblems for commercialisation.     

Debt for brands: tracking down a bias in financing photovoltaic projects in Germany

What kinds of PV project configurations do lenders prefer to finance? Recent developments in the field of renewable energy project finance have reinforced the need for investigation, as fundraising has become more challenging and project evaluation by banks more demanding. To contribute to the limited research in this field, we focus on photovoltaic projects and report from an Adaptive Choice-Based Conjoint experiment with German experts in project finance. We find a bias which we call “debt for brands”. Simulations reveal that debt investors prefer projects with premium brand technology (modules, inverters) to low-cost technology. Although we assumed that lenders prefer projects with the highest Debt Service Cover Ratio (DSCR), they favor projects with lower DSCR, as long as those projects include premium brand technology. We find that, if premium brands were engaged, lenders would also choose projects with higher risk. Our findings have implications for renewable energy project finance in practice and research.     

双碳约束下煤化工行业节煤降碳减污协同

在碳达峰碳中和背景下,煤化工行业应采取更为积极的二氧化碳减排措施.基于煤化工行业原料结构调整、燃料结构调整、节能技术改造、末端捕集技术和产业结构调整五大节煤降碳措施力度不同,采用下游部门需求法和项目法以及大气污染物减排模型,核算预测3种情景(基准、政策和强化)煤化工行业煤炭消耗和二氧化碳排放变化,以及大气污染物协同减排效应.结果表明,煤化工行业基准和政策情景下煤炭消费量预计在“十四五”后期达峰,峰值分别为9.6亿t和9.3亿t;强化情景下有望在“十四五”前期达峰,峰值约为9.1亿t.二氧化碳排放量在基准、政策和强化情景下分别于“十五五”末期、“十四五”末期和“十四五”前期达峰,达峰量分别为6.4亿、 5.7亿和5.5亿t.控制现代煤化工项目建设规模、挖掘原料替代的空间以及节能技术改造是减少煤化工行业煤耗和二氧化碳排放的重要措施手段.实施煤化工行业节煤降碳措施,政策情景下预计到2035年每年可协同减少SO₂、 NO_x、 PM和VOCs等大气污染物排放3.7万、 4.3万、 1.1万和2.8万t.     

超声强化金刚石膜电极电化学降解效率的机制

从电化学氧化的传质过程、吸附与脱附、电极反应3个步骤,考察了超声强化金刚石膜电极(BDD)电化学降解效率的机制.超声对上述3个步骤都有显著影响.超声增强了污染物的传质过程,苯酚和邻苯二甲酸的传质系数分别由5.4×10-6m/s和6.7×10-6m/s增大至2.0×10-5m/s,提高了270%和199%.污染物在BDD电极表面的电化学吸附特性决定了超声对吸附与脱附过程的作用.苯酚的吸附量大,但中间产物难于脱附,超声虽然使得吸附量由6.49×10-10mol/cm2减小至1.39x10-10mol/cm2,但促进了产物的脱附,产生了正效应,有利于直接氧化,氧化峰电流提高了32%;邻苯二甲酸的吸附能力弱,超声使得吸附量由1.25×10-11mol/cm2进一步减小至3.11×10-12mol/cm2,产生了负效应,导致直接氧化消失.超声可以显著提高BDD电极的降解效率,而且对苯酚降解的促进作用更为明显.苯酚的平均电化学氧化能量利用率提高了287%,高于邻苯二甲酸的224%,这主要是因为超声可以同时强化苯酚的直接氧化和间接氧化,但对于邻苯二甲酸,间接氧化得到了加强,却不发生直接氧化.     

Portfolio-Based Electricity Generation Planning: Policy Implications For Renewables And Energy Security

Renewable generating technologies offer an effective means for climate change mitigation. Policy makers, however, are wary because of the widespread perception that these technologies cost more than conventional alternatives so that increasing their deployment will raise overall electricity generating costs. Energy planning represents an investment-decision problem. Investors commonly evaluate such problems using portfolio theory to manage risk and maximize portfolio performance under a variety of unpredictable economic outcomes. Energy planners need to similarly abandon their reliance on traditional, “least-cost” stand-alone kWh generating cost measures and instead evaluate conventional and renewable energy sources on the basis of their portfolio cost – their cost contribution relative to their risk contribution to a mix of generating assets. Energy security generally focuses on the threat of abrupt supply disruptions. This paper suggests a more profound aspect: mitigating fossil price volatility. An extensive body of research indicates that fossil volatility significantly disrupts the economies of consuming nations, potentially exacting hundreds of billions of dollars from the US and EU economies alone. Energy security is reduced when countries hold inefficient portfolios that are needlessly exposed to fossil price risks. This paper describes essential portfolio-theory ideas and uses three case studies to illustrate how electricity-generating mixes can benefit from additional shares of wind, geothermal and other renewables. Compared to existing, fossil-dominated mixes, efficient portfolios reduce generating cost while including greater renewables shares in the mix thereby enhancing energy security. Though counter-intuitive, the idea that adding more costly renewables can actually reduce portfolio-generating cost is consistent with basic finance theory. An important implication is that in dynamic and uncertain environments, the relative value of generating technologies must be determined not by evaluating alternative resources, but by evaluating alternative resource portfolios.