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[en] This article explores efficient climate policies in terms of investment streams into fossil and renewable energy technologies. The investment decisions maximise social welfare while observing a probabilistic guardrail for global mean temperature rise under uncertain technology and climate parameters. Such a guardrail constitutes a chance constraint, and the resulting optimisation problem is an instance of chance constrained programming, not stochastic programming as often employed. Our analysis of a model of economic growth and endogenous technological change, MIND, suggests that stringent mitigation strategies cannot guarantee a very high probability of limiting warming to 2 oC since preindustrial time under current uncertainty about climate sensitivity and climate response time scale. Achieving the 2 oC temperature target with a probability P* of 75% requires drastic carbon dioxide emission cuts. This holds true even though we have assumed an aggressive mitigation policy on other greenhouse gases from, e.g., the agricultural sector. The emission cuts are deeper than estimated from a deterministic calculation with climate sensitivity fixed at the P* quantile of its marginal probability distribution (3.6 oC). We show that earlier and cumulatively larger investments into the renewable sector are triggered by including uncertainty in the technology and climate response time scale parameters. This comes at an additional GWP loss of 0.3%, resulting in a total loss of 0.8% GWP for observing the chance constraint. We obtained those results with a new numerical scheme to implement constrained welfare optimisation under uncertainty as a chance constrained programming problem in standard optimisation software such as GAMS. The scheme is able to incorporate multivariate non-factorial probability measures such as given by the joint distribution of climate sensitivity and response time. We demonstrate the scheme for the case of a four-dimensional parameter space capturing uncertainty about climate and technology.
[en] The analysis presented here follows the design specified by the Energy Modeling Forum (EMF) Transition Scenarios study on achieving climate stabilization goals with delayed participation by developing countries. We use the MERGE model to evaluate the core EMF scenarios for both the international and the US-specific studies. Our results indicate that a radiative forcing target equivalent to 450 ppmv CO2-e cannot be met even allowing for full participation and overshoot during the entire 21st century. With delayed participation of developing countries, a target of 550 ppmv CO2-e is only attainable with pessimistic assumptions about economic growth, and even then only at very high cost. A target of 650 ppmv CO2-e can be met with delayed participation for a more affordable cost. We highlight sensitivities to the core scenarios in two key dimensions: (1) the effect of the unfolding global financial crisis on the rate of economic growth and (2) the willingness of initially non-participating countries to agree at the beginning of the next commitment period (i.e. 2012) to join the coalition at a pre-specified date in the future. We find that while the recession does not fundamentally change the crucial role of developing country involvement, advance agreement on their part to future targets could substantially reduce costs for all countries. (author)
[en] The hydrogen is a clean and very efficient fuel, its combustion does not produce gases of greenhouse effect, ozone precursors and residual acids. Also the hydrogen produced by friendly energy sources with the environment like nuclear energy could help to solve the global problems that it confronts the energy at present time. Presently work fuel cycles of hydrogen production technologies in Mexico are judged, by means of a structured methodology in the concept of sustainable development in its social, economic and environmental dimensions. The methodology is divided in three scenarios: base, Outlook 2030 and capture of CO2. The first scenario makes reference to cycles analysis in a current context for Mexico, the second taking in account the demand projections reported by the IAEA in its report Outlook and the third scenario, capture of CO2, the technologies are analyzed supposing a reduction in capture costs of 75%. Each scenario also has four cases (base, social, environmental and economic) by means of which the cycles are analyzed in the dimensions of sustainable development. For scenarios base and capture, results show that combination nuclear energy- reformed of gas it is the best alternative for cases base and economic. For social case, the evaluated better technology is the hydraulics, and for environmental case, the best option is represented by the regenerative thermochemistry cycles. The scenario Outlook 2030 show a favorable tendency of growth of renewable sources, being the aeolian energy the best technology evaluated in the cases base and environmental, the hydraulics technology in the social case and in the economic case the reformed of natural gas that uses nuclear heat. (Author)
[en] This workshop provided a forum for industry experts, government agencies, and various other stakeholders to discuss issues related to small and medium hydro technologies. The aim of the workshop was to provide practical information related to the challenges and benefits of small and medium hydro development for designers, developers, and investors. Attendees discussed approvals procedures, regulations, and government policies related to small and medium hydro developments. An overview of small and medium hydro technologies in relation to the electricity sector was presented. Modelling packages for hydro design were reviewed, and recent technology innovations were discussed. Small and medium hydro projects in various countries were outlined. The workshop was divided into the following 3 sessions: (1) project approvals, (2) project approvals and project assessment, and (3) hydrokinetic power. The workshop featured 12 presentations, of which 3 have been catalogued separately for inclusion in this database. tabs., figs.
[en] Energy security has become a popular catch phrase, both in the scientific arena as well as in the political discussion. Yet, in general the applied concepts of energy security are rather vague. This paper sheds some light on concepts and indicators of energy security. First, we conceptually discuss the issue of energy supply security and explain why it is not to handle by one science alone and what economics may contribute in order to structure the topic. After providing a brief survey of existing attempts to define or measure energy security we suggest an additional dimension along which indicators of energy security may be classified: ex-post and ex-ante indicators. Finally, we illustrate our concept on the basis of several simplified indicators. While ex-post indicators are mostly based on price developments, ex-ante indicators are to a greater extent aimed at illustrating potential problems. Our illustration suggests that it is worthwhile to take into account the market structure along with the political stability of exporting countries.
[en] Coal is found in huge amounts throughout the world and is expected to play a crucial role as an abundant energy source. However, one critical issue in promoting coal utilization is controlling environmental pollution. Clean coal technologies are needed to utilize coal in an environmentally acceptable way and to improve coal utilization efficiency. This paper describes coal's role in China's energy system and the environmental issues related to coal use. Coal is responsible for 90% of the SO2 emissions, 70% of the dust emissions, 67% of the NOx emissions, and 70% of the CO2 emissions. But as the most abundant energy resource, it will continue to be the dominant energy supply for a long time. Therefore, the development and deployment of clean coal technologies are crucial to promote sustainable development in China. Clean coal technologies currently being developed in China are described including high efficiency combustion and advanced power generation technologies, coal transformation technologies, IGCC (integrated gasification combined cycle) and carbon capture and storage (CCS). Although China only recently began developing clean coal technologies, there have been many successes. Most recent orders of coal-fired power plants are units larger than 600 MW and new orders for supercritical and ultra supercritical systems are increasing rapidly. Many national research programs, industrial research programs and international collaboration projects have been launched to develop on IGCC and CCS systems in China. Finally, suggestions are given on how to further promote clean coal technologies in China.