佛得角圣文森特岛能源发展概况、问题与建议

佛得角能源矿产资源缺乏,电力生产主要依赖进口化石能源进行热力发电,尽管可再生能源较为丰富,但尚未充分开发利用。通过对佛得角能源和电力市场的全面考察,统筹考虑圣文森特岛现有电力装机规模、电力生产与消费形势、可再生能源发展潜力,提出圣文森特岛应调整优化能源结构,提高可再生能源在能源供给中的比例;升级改造配电网,推进智能电网建设;鼓励私营业主与企业参与电力设施投资,逐步建立适应 IPP电力投资的政策框架。     

Interactions between electricity generation sources and economic activity in two Nord Pool systems. Evidence from Estonia and Sweden

The interactions between electricity sources and industrial production in Estonia and Sweden are analysed based on monthly data. The availability of data defines the time spans from January 2010 to September 2015 for Sweden and from April 2010 to December 2014 for Estonia. These countries are particularly interesting to study because of their dissimilar generation mix. Estonia’s generation mix is based on oil shale, while Sweden’s is based on nuclear plants and hydroelectricity. In short, both countries’ energy mixes are based on endogenous natural resources. The ARDL model was applied, allowing the long-run and short-run effects to be captured. The results prove that economic growth is sustained by natural endogenous resources. Estonia should continue to improve the usage of renewable energies, using fossil sources in support, in order to reduce emissions and to meet international environmental commitments. Sweden should promote the efficient usage of various renewable sources.     

Electricity provision with intermittent sources of energy

We analyze the interaction between a reliable source of electricity production and intermittent sources such as wind or solar power. We first characterize the optimal energy mix, emphasizing the availability of the intermittent source as a major parameter for the optimal investment in capacity. We then analyze decentralization through competitive market mechanisms. We show that decentralizing the efficient energy mix requires electricity to be priced contingently on the availability of the intermittent source. By contrast, traditional meters impose uniform pricing, which distorts the optimal mix of energy sources. Decentralizing the efficient energy mix with uniform prices requires either cross-subsidies from the intermittent source to the reliable source of energy or structural integration of the two types of technology.     

Climate change and the transition to a low carbon economy – Carbon targets and the carbon budget

Carbon intensive fuels generate a significant negative externality which is quite relevant for climate change mitigation policy. We propose a dynamic growth model where output is produced using two types of energy sources: fossil fuel and renewable energy. Fossil fuel discovery, extraction, and associated costs are incorporated in our model together with the dynamics of greenhouse gas emissions and consequent damages. Consistent with the empirical facts, our numerical solutions suggest that fossil fuels, especially coal, should not be exploited to depletion. Furthermore, renewable energy should be gradually phased in to meet targets consistent with the Paris 2015 agreement. We show that adopting those policies should slow down the growth rate of cumulative emissions; but the outcome is contingent upon the carbon emission targets set for advanced countries, as distinct from those assigned to developing countries.     

Energy substitutions, climate change and carbon sinks

We determine the optimal exploitation time-paths of two energy resources, one being depletable and polluting, namely a fossil fuel, the other being renewable and clean. These optimal paths are considered along with the two following features. First, the cumulative atmospheric pollution stock is set not to exceed some critical threshold and second, the polluting emissions produced by the use of fossil fuel can be reduced at the source and stockpiled in several carbon sinks of limited capacity. We show that, if the renewable resource flow is abundant, the optimal path requires that sequestration is implemented only once the ceiling is reached. Moreover, the reservoirs should be completely filled by increasing order of their respective sequestration costs.     

Energy substitutions,climate change and carbon sinks

We determine the optimal exploitation time-paths of two energy resources, one being depletable and polluting, namely a fossil fuel, the other being renewable and clean. These optimal paths are considered along with the two following features. First, the cumulative atmospheric pollution stock is set not to exceed some critical threshold and second, the polluting emissions produced by the use of fossil fuel can be reduced at the source and stockpiled in several carbon sinks of limited capacity. We show that, if the renewable resource flow is abundant, the optimal path requires that sequestration is implemented only once the ceiling is reached. Moreover, the reservoirs should be completely filled by increasing order of their respective sequestration costs.     

Producing energy in a stochastic environment: Switching from non-renewable to renewable resources

In this paper, we study the determinants of switching from non-renewable natural resource inputs to renewable resource inputs in energy production. We assume that the stocks of both natural resources are stochastic, and that the adoption of renewable resources is costly and irreversible. Our formulation gives raise to an optimal stopping/switching problem that cannot be solved analytically, then we turn to numerical simulations. Our results suggest that the optimal switching time depends not only on the uncertainty parameters, but also on energy demand, costs, and the relative productivity of the resources.     

The atmospheric carbon resilience problem: A theoretical analysis

We study a dynamic carbon pollution model where carbon accumulates both inside a nonrenewable and a renewable reservoir with a constant regeneration rate. Two primary energy sources are available: a cheap exhaustible fossil fuel (coal) and an expensive clean energy alternative (solar). To avoid catastrophic climate events, the global carbon concentration has to remain below some critical mandated ceiling. We show that there exists an upper bound on the coal endowment that can be consumed, which distinguishes two main cases: coal is initially abundant or scarce. If the energy sector has to provide a constant aggregate energy flow to the final users, cost-effectiveness requires that the global ceiling should be attained only when solar energy is introduced. Then the economy stays forever at the ceiling and coal use is progressively replaced by solar energy use. In the abundant coal case, this energy sources substitution process lasts for an infinite duration while in the scarce coal case, coal exploitation ends in finite time. Under a welfare maximization criterion, if coal is abundant, we show that the economy may follow a sequence of phases at the ceiling and below the ceiling before the final transition towards clean energy.     

The atmospheric carbon resilience problem: A theoretical analysis

We study a dynamic carbon pollution model where carbon accumulates both inside a nonrenewable and a renewable reservoir with a constant regeneration rate. Two primary energy sources are available: a cheap exhaustible fossil fuel (coal) and an expensive clean energy alternative (solar). To avoid catastrophic climate events, the global carbon concentration has to remain below some critical mandated ceiling. We show that there exists an upper bound on the coal endowment that can be consumed, which distinguishes two main cases: coal is initially abundant or scarce. If the energy sector has to provide a constant aggregate energy flow to the final users, cost-effectiveness requires that the global ceiling should be attained only when solar energy is introduced. Then the economy stays forever at the ceiling and coal use is progressively replaced by solar energy use. In the abundant coal case, this energy sources substitution process lasts for an infinite duration while in the scarce coal case, coal exploitation ends in finite time. Under a welfare maximization criterion, if coal is abundant, we show that the economy may follow a sequence of phases at the ceiling and below the ceiling before the final transition towards clean energy.     

A model of technological breakthrough in the renewable energy sector

Models with induced technological change in the energy sector often predict a gradual expansion of renewable energies, and a substantial share of fossil fuels remaining in the energy mix through the end of our century. However, there are historical examples where new products or technologies expanded rapidly and achieved a high output in a relatively short period of time. This paper explores the possibility of a ‘technological breakthrough’ in the renewable energy sector, using a partial equilibrium model of energy generation with endogenous R&D. Our results indicate, that due to increasing returns-to-scale, a multiplicity of equilibria can arise. In the model, two stable states can coexist, one characterized by a lower and one by higher supply of renewable energy. The transition from the low-output to the high-output equilibrium is characterized by a discontinuous rise in R&D activity and capacity investments in the renewable energy sector. The transition can be triggered by a rise in world energy demand, by a drop in the supply of fossil fuels, or by policy intervention. Under market conditions, the transition occurs later than in the social optimum. Hence, we identify a market failure related to path-dependence and technological lock-in, that can justify a strong policy intervention initially. Paradoxically, well-intended energy-saving policies can actually lead to higher emissions, as they reduce the incentives to invest in renewable energies by having a cushioning effect on the energy price. Hence, these policies should be supplemented by other instruments that restore the incentives to invest in renewable energies. Finally, we discuss the influence of monopoly power in the market for innovations. We show that market power can alleviate the problem of technological lock-in, but creates a new market failure that reduces static efficiency.     

偏向技术进步有利于可再生能源转型吗——基于要素替代弹性的证据

尽管偏向技术进步被视为可再生能源消费最重要的驱动因素之一，但现有研究普遍忽视其对可再生能源转型的影响。基于偏向技术进步理论框架，运用固定效应随机前沿生产函数分析技术进步的偏向性以及化石能源与可再生能源间的替代弹性，进而判断2000—2017年中国内地30个省域的偏向技术进步是否推动了可再生能源转型。研究发现，整体上技术进步在化石能源与可再生能源间偏向于使用更多化石能源，且二者之间具有替代关系，这表明整体上偏向技术进步不利于可再生能源转型。分省域看，仅有上海、浙江和湖北的技术进步偏向于使用更多可再生能源，且可再生能源能够有效替代化石能源，这表明上述省份的偏向技术进步有利于可再生能源转型。     

Substitute or complement? Assessing renewable and nonrenewable energy in OECD countries

The elasticity of interfuel substitution between renewable and nonrenewable energy is key to establishing effective climate change policy. This is the first study to estimate the elasticity of substitution between different fossil fuels and renewable resources. We used 12 manufacturing industry-level datasets for the OECD countries from 1995 to 2009. We found a complementary relationship from nonrenewable energy to renewable energy in eight industries, whereas a substitute relationship was maintained for four industries. In particular, the food and pulp industries had a strong complementary relationship.     

Regulatory design and incentives for renewable energy

Increasing electric power production from renewable energy sources is currently one of the major objectives of energy policy. The intermittent nature of renewables, such as wind and solar, necessarily imposes complex trade-offs for regulatory objectives, such as resource adequacy (and system reliability) versus reductions in green house gas emissions. We develop a highly stylized model of investments in order to derive insights regarding the workings of regulatory incentives for increased renewable energy. We first show that incentives are indeed needed when there are significant economies of scale in the form of “learning by doing” or alternatively, when there is excess capacity in conventional technology due to legacy investments. We analyze two different regulatory schemes (feed-in tariffs and renewable portafolio standards) aimed at increasing investment in renewable capacity. We show that neither scheme is capable of inducing the socially optimal level of investment in renewable capacity. A single feed-in tariff fails to induce optimal investment as a feed-in tariff exceeding marginal costs of conventional technology incentivizes over-development of the most attractive sites which preempts investment in less attractive, yet socially valuable sites. A renewable portfolio standard that promotes increased investment in renewable technology induces under-investment in the conventional technology. These results suggest that a “clinical” regulatory design, that is, one that promotes the right amount of renewable capacity without affecting conventional capacity is a challenging proposition.     

Support to renewable energy sources and carbon capture and sequestration: comparison of alternative green tax reforms

We compare the economic and environmental effects of several specifications of a green tax reform (GTR) where tax revenues are used to support renewable energy sources (RESs) and carbon capture and sequestration (CCS) activities. With this aim, we propose an equilibrium model where final-goods production uses labour and energy, and energy production uses nonpolluting RES and polluting fossil fuels. The comparison is based on three key indicators: output per worker, energy intensity and the ratio of renewables over nonrenewables. We test five variations of the GTR in addition to the no-policy case. Results show that a GTR as the one we propose here never provides a double dividend. There are environmental benefits but at the expense of the economy. Additionally, for lower tax levels, prioritizing RES support has lower economic costs and potential environmental benefits. For higher tax levels, CCS support becomes more competitive.     

Renewable energy subsidies: Second-best policy or fatal aberration for mitigation?

This paper evaluates the consequences of renewable energy policies on welfare and energy prices in a world where carbon pricing is imperfect and the regulator seeks to limit emissions to a (cumulative) target. The imperfectness of the carbon price is motivated by political concerns regarding distributional effects of increased energy prices. Hence, carbon prices are considered to be temporarily or permanently absent or endogenously constrained by their effect on energy prices. We use a global general equilibrium model with an intertemporal fossil resource sector and calculate intertemporally optimal policies from a broad set of policy instruments including carbon taxes, renewable energy subsidies and feed-in-tariffs, among others. If carbon pricing is permanently missing, mitigation costs increase by a multiple (compared to the optimal carbon pricing policy) for a wide range of parameters describing extraction costs, renewable energy costs, substitution possibilities and normative attitudes. Furthermore, we show that small deviations from the second-best subsidy can lead to strong increases in emissions and consumption losses. This confirms the rising concerns about the occurrence of unintended side effects of climate policy – a new version of the green paradox. Smart combinations of carbon prices and renewable energy subsidies, however, can achieve ambitious mitigation targets at moderate additional costs without leading to high energy price increases.     

Growth in global materials use, GDP and population during the 20th century

The growing industrial metabolism is a major driver of global environmental change. We present an assessment of the global use of materials since the beginning of the 20th century based on the conceptual and methodological principles of material flow accounting (MFA). On the grounds of published statistical data, data compilations and estimation procedures for material flows not covered by international statistical sources, we compiled a quantitative estimate of annual global extraction of biomass, fossil energy carriers, metal ores, industrial minerals and construction minerals for the period 1900 to 2005. This period covers important phases of global industrialisation and economic growth. The paper analyses the observed changes in the overall size and composition of global material flows in relation to the global economy, population growth and primary energy consumption. We show that during the last century, global materials use increased 8-fold. Humanity currently uses almost 60 billion tons (Gt) of materials per year. In particular, the period after WWII was characterized by rapid physical growth, driven by both population and economic growth. Within this period there was a shift from the dominance of renewable biomass towards mineral materials. Materials use increased at a slower pace than the global economy, but faster than world population. As a consequence, material intensity (i.e. the amount of materials required per unit of GDP) declined, while materials use per capita doubled from 4.6 to 10.3 t/cap/yr. The main material groups show different trajectories. While biomass use hardly keeps up with population growth, the mineral fractions grow at a rapid pace. We show that increases in material productivity are mostly due to the slow growth of biomass use, while they are much less pronounced for the mineral fractions. So far there is no evidence that growth of global materials use is slowing down or might eventually decline and our results indicate that an increase in material productivity is a general feature of economic development.     

Considering Aquacultural Externality in Coastal Land Allocation Decisions in India

Commercial aquaculture in India has come under attack for having caused negative agricultural and environmental impacts. This paper formulates an interactive model of non-renewable and renewable resources to characterize land allocations between aquaculture and agriculture in ecologically and economically sustainable fashion. Through an empirical application, various economic and policy circumstances that affect the optimal land allocation mix are evaluated. The aquaculture industry must address two economic effects: off-site negative effects on renewable food and other coastal resources, and on-site self-pollution of shrimp ponds. Current regulatory and land-use policies are inadequate to address these effects.     

Race to burn the last ton of carbon and the risk of stranded assets

A cap on global warming implies a tighter carbon budget which can be enforced with a credible second-best renewable energy subsidy designed to lock up fossil fuel and curb cumulative emissions. Such a subsidy brings forward the end of the fossil fuel era but accelerates fossil fuel extraction and global warming in the short run. A weaker fossil fuel oligopoly implies that anticipation of a given global carbon budget induces fossil producers to deplete reserves more voraciously and accelerate global warming. This race to burn the last ton of carbon is more intensive for the feedback than open-loop Nash equilibrium, so that the Green Paradox effect of a renewable energy subsidy is stronger. There is an intermediate phase of limit pricing to keep renewable energy producers at bay, which becomes much more relevant when a cap on global warming is enforced. A stronger fossil fuel oligopoly lengthens the period of limit pricing and typically brings forward the carbon-free era. Finally, the mere risk of a cap on global warming being enforced at some unknown, future date makes fossil fuel extraction more voracious and accelerates global warming.     

The share of the global energy mix: Signs of convergence?

This paper investigates the convergence behaviour regarding the share of global energy mix, as measured by primary energy consumption. Recent studies that employ stationary tests of panel data suggest that such data support the convergence hypothesis; however, some drawbacks exist, as these studies rely on methods that do not necessarily imply a sufficient condition for convergence. This paper adopts the concept of relative convergence as proposed by Phillips and Sul (2007), which employs a time‐varying, idiosyncratic component. We choose to focus on various sources’ global primary energy consumption and investigate the long‐ run dynamic behaviour by source. The key finding of this paper is that two distinct clubs of convergence of energy can be determined: renewable and non‐renewable energy clubs of convergence.     

Nuclear energy: Tenfold expansion or phase-out?

Today, consensus is strengthening that mankind ought to prevent atmospheric carbon dioxide concentrations from more than doubling, since such a doubling is likely to cause a significant interference with the planet's climate system, to which it might prove difficult to adapt. Nuclear energy possesses large disadvantages, among which waste, proliferation and safety. An expansion of nuclear energy would encounter great social, institutional and economic barriers. Because the 21st century requires a radical transformation of global energy production and consumption towards nonfossil fuels, however, it is one of the noncarbon emitting alternatives that, at present, deserve enhanced research and development efforts. If nuclear energy were expanded 10-fold, it could contribute significantly to mitigating carbon emissions: a 10-fold expansion of nuclear energy could avoid about 15% of cumulative carbon emissions over the period 2000–2075. Nuclear energy, however, can be no panacea for the problem of global warming. Even with a massive expansion, nuclear energy should be complemented by drastic fossil fuel decarbonization measures or the development of renewable energy resources. Preferably, a combination of both should be targeted and complemented by far-reaching efficiency and savings regimes. Since the risks for humanity resulting from climate change are high, it would be unwise to currently abandon any noncarbon energy resource, including fission. A central thrust of continued research and development into nuclear energy ought to be the design of satisfactory nuclear waste depositories and of safe reactors that are less susceptible to proliferation risks.