• Energy Research

Abstract Considering the unclear nuclear future of Japan after Fukushima Dai-ichi nuclear power plant accident since Mar. 11, 2011, this study assesses a series of energy consumption scenarios including the reference scenario, nuclear limited scenarios and current nuclear use level scenario for Japan in 2030 by the G-CEEP (Glocal Century Energy Environment Planning) model. The simulation result for each scenario is firstly presented in terms of primary energy consumption, electricity generation, CO2 emission, marginal abatement cost and GDP (gross domestic product) loss. According to the results, energy saving contributes the biggest share in total CO2 emission reduction, regardless of different nuclear use levels and different CO2 emission reduction levels. A certain amount of coal generation can be retained in the nuclear limited scenarios due to the applying of CCS (carbon capture and storage). The discussion indicates that Japan needs to improve energy use efficiency, increase renewable energy and introduce CCS in order to reduce the dependence on nuclear power and to achieve CO2 emission reduction target in 2030. In addition, it is ambitious for Japan to achieve the zero nuclear scenario with 30% CO2 emission reduction which will cause a marginal abatement cost of 383 USD/tC and up to −2.54% GDP loss from the reference scenario. Dealing with the nuclear power issue, Japan is faced with a challenge as well as an opportunity.

Abstract This study estimates the elasticities of substitution for China from 1953 to 2006 by the two-level constant elasticity of substitution (CES) production function with three factor inputs: capital stock, labor and energy. A technological change rate and non-constant returns to scale are under considered. All possible combinations and two other subdivided periods are carried out respectively and their technological change rates, elasticities of substitution and returns to scale are found. This study also provides an analysis of production efficiency by using marginal productivity of specific factor input according to the estimated results and distinguishes the marginal productivities deriving from the three different combinations. It suggests that the decision-makers of China need to consider the effects of different factor inputs on GDP growth.

Climate change mitigation to limit warming to 1.5 °C or well below 2 °C, as suggested by the Paris Agreement, can rely on large-scale deployment of land-related measures (e.g. afforestation, or bioenergy production). This can increase food prices, and hence raises food security concerns. Here we show how an inclusive policy design can avoid these adverse side-effects. Food-security support through international aid, bioenergy tax, or domestic reallocation of income can shield impoverished and vulnerable people from the additional risk of hunger that would be caused by the economic effects of policies narrowly focussing on climate objectives only. In the absence of such support, 35% more people might be at risk of hunger by 2050 (i.e. 84 million additional people) in a 2 °C-consistent scenario. The additional global welfare changes due to inclusive climate policies are small (<0.1%) compared to the total climate mitigation cost (3.7% welfare loss), and the financial costs of international aid amount to about half a percent of high-income countries' GDP. This implies that climate policy should treat this issue carefully. Although there are challenges to implement food policies, options exist to avoid the food security concerns often linked to climate mitigation. Environmental Research Letters, 13 (7) ISSN:1748-9326 ISSN:1748-9318

Abstract Energy–exergy analysis and parameter design optimization of the KCS-11 solar system with an auxiliary superheater are studied in low-grade thermal energy conversion (LTEC). Firstly, from a thermodynamics point of view, the corresponding calculation model is built to solve the system state points as well as the exergy input/output/loss for each system component. And then, according to the characteristics of the KCS-11 solar system, the verification items are given to verify the correctness of the calculation model. Afterward the model is proved to be correct by sampling check a set of calculation data. On that basis, the corresponding parameter design optimization and system performance analysis are carried out from the viewpoint of the maximization of the exergy output in KCS-11 solar system at a certain scale. Results show that the mass flow rates of working fluid and solar collector subcycle and also ammonia mass fraction are important system operation parameters that should be optimized to deduce the irreversible behavior of the solar system for producing more useful energy. Meanwhile, the heat-transfer rate distribution ratio of the superheater should be large enough to ensure that the expanding vapor in the turbine is superheated. Finally, an optimization calculation case is designed for illustration by using the monthly mean solar radiation statistics in Kumejima Island of Japan. In this case, the maximum generated power is 491 kW showing 35.6% exergy efficiency and 6.48% energy efficiency of the system for the month of August. The size of the system in terms of power generated of each major equipment is listed as follows: solar evaporator (370 kW), superheater (106 kW), condenser (298 kW), turbine (491 kW), separator (43 kW), absorber (37 kW), pump (8 kW), regenerator (38 kW), and diffuser (17 kW). And the main system exergy losses are associated with internal consumptions of exergy in turbine (92 kW) and condenser (97 kW) due to irreversibilities. In this way, the maximum annual power generation of the KCS-11 solar system is about 553,520 kW h.

Abstract Since 1978, Liaoning province has experienced spectacular economic growth, which has led to more energy consumption. The purpose of this paper is to explore the decoupling status between energy consumption and economic growth in Liaoning Province. Firstly, the generalized LMDI method is used to explore the driving forces governing production energy consumption in Liaoning province. Then, the combination of Tapio decoupling indicator and generalized LMDI method is utilized to study what the decoupling status occurred in Liaoning Province and why the decoupling status appeared. During the study period, only four decoupling status occurred: expansive negative decoupling, expansive coupling, weak decoupling, and strong decoupling. The energy intensity decoupling effect played a positive role in the appearance of decoupling. However, the economic structure decoupling effect and investment decoupling effect played a negative role in the appearance of decoupling. Over the study period, the energy structure decoupling effect and labour decoupling effect played a relative small role in the appearance of decoupling.