Methodology and applications of city level CO2 emission accounts in China

China is the world's largest energy consumer and CO2 emitter. Cities contribute 85% of the total CO2 emissions in China and thus are considered as the key areas for implementing policies designed for climate change adaption and CO2 emission mitigation. However, the emission inventory construction of Chinese cities has not been well researched, mainly owing to the lack of systematic statistics and poor data quality. Focusing on this research gap, we developed a set of methods for constructing CO2 emissions inventories for Chinese cities based on energy balance table. The newly constructed emission inventory is compiled in terms of the definition provided by the IPCC territorial emission accounting approach and covers 47 socioeconomic sectors, 17 fossil fuels and 9 primary industry products, which is corresponding with the national and provincial inventory. In the study, we applied the methods to compile CO2 emissions inventories for 24 common Chinese cities and examined uncertainties of the inventories. Understanding the emissions sources in Chinese cities is the basis for many climate policy and goal research in the future

Competing coalitions: The politics of renewable energy and fossil fuels in Mexico, South Africa and Thailand

This paper analyses why middle-income countries incentivize renewable energy despite inexpensive domestic fossil fuel resources and lack of international support. We examine the politics of renewable energy programs in Mexico, South Africa and Thailand. All three countries hold abundant local fossil fuel and renewable energy resources. We argue that renewable energy programs become implementable policy options in fossil fuel resource-rich middle-income countries when coalitions of powerful political actors support them. This study presents an analysis of the domestic coalitions in support of and those in opposition to renewable energy policies from a discourse network perspective. Discourse networks reflect actors and the arguments they share to advance or hamper the policy process. The analysis draws on a data set of 560 coded statements in support or opposition of renewable energy from media articles, policy documents and interviews. Findings show similar structures of competing coalitions in all three countries, with the discourse in all three countries revealing strong linkages between environmental and economic considerations

Taming the 'masculine pioneers'? Changing attitudes towards energy efficiency amongst private landlords and tenants in New Zealand: A case study of Dunedin

New Zealand's housing is some of the poorest quality and hardest to heat in the developed world. The private rented sector in particular offers the worst quality accommodation to the country's poorest and most vulnerable tenants. Previous research has established a range of economic and socio-cultural explanations for the prevalence of poor conditions in private rented accommodation with the 'principal-agent problem' dominating the debate. This paper reports the findings from research in Dunedin, a city with some of the coldest conditions and least energy efficient properties in the country. The study was undertaken in 2015 and involved 30 in-depth interviews with landlords exploring their attitudes towards improving the thermal performance and energy efficiency of their properties. The results revealed a shift in attitudes amongst landlords over a period of about 5 years, with many becoming more amenable to investing in insulation and low energy heat sources. This shift has ostensibly been driven by pressure from tenants who appear to be departing from established cultural norms and becoming intolerant of cold homes and high bills. The study highlights how socio-cultural factors, such as growing expectations regarding warmth and comfort in the home, can disrupt established cultural norms and economic rationales to bring about change

A review of physical supply and EROI of fossil fuels in China

This paper reviews China’s future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that China’s total oil production will likely reach its peak, at about 230 Mt/year (or 9.6 EJ/year), in 2018; its total gas production will peak at around 350 Bcm/year (or 13.6 EJ/year) in 2040, while coal production will peak at about 4400 Mt/year (or 91.9 EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found

Assessment of electrical vehicles as a successful driver for reducing CO2 emissions in China

This paper analyses the impacts of the gasoline vehicle replacement programme with EVs at different penetration rates on petroleum and electricity sectors and their CO2 emissions. The study utilises a top-down- type Environmental Input-Output (EI-O) model. Our results show that the replacement of gasoline cars with EVs causes greater impacts on total gasoline production than on total electricity generation. For example, at 5%, 20%, 50%, 70% and 100% gasoline vehicle replacement with EVs, the total gasoline production decreases by 1.66%, 6.65%, 16.62%, 23.27% and 33.24% in policy scenario 1, while the total electricity production only increases by 0.71%, 2.82%, 7.05%, 9.87% and 14.10%. Our study confirms that the gasoline vehicle replacement with EVs, powered by 80% coal, has no effect on overall emissions. The CO2 emissions reduction in the petroleum sector is offset by the increase in CO2 emissions in the electricity sector, leaving the national CO 2 emissions unchanged. By decarbonising the electricity sector, i.e. using 30% less coal in electricity generation mix, the total CO2 emissions will be reduced by 28% (from 10,953 to 7,870 Mt CO 2 ) on the national level. The gasoline vehicle replacement programme with EVs, powered by 50% coal-based electricity, helps reduce CO2 emissions in petroleum sector and contributes zero or a very small proportion of additional CO2 emissions to the electricity sector (policy scenario 2 and 3). We argue that EVs can contribute to a reduction of petroleum dependence, air quality improvement and CO2 emission reduction only when their introduction is accompanied by aggressive electricity sector decarbonisation

Assessment of solar shading strategies in low-income tropical housing: the case of Uganda

Developing countries in tropical and subtropical areas will be the worst hit by climate change. Very little research has been done to assess the impact of climate change on thermal comfort in low-income housing in these regions. The effects of solar shading strategies and solar absorptance properties of walls and roofs on thermal comfort in Ugandan low-income housing are studied in this paper. Various shading strategies including curtains, roof and window overhangs, veranda and trees as well as effects of painting on solar heat gain and thermal comfort are modelled using EnergyPlus software. An adaptive approach for naturally ventilated buildings defined by the European Committee for Standardization standard BS EN 15251:2007 is used to assess the conditions. According to the results, solar shading is less effective in meeting thermal comfort requirements and it should be used in conjunction with other strategies to achieve desirable results. White painting, in contrast, significantly improved the conditions and significantly reduced the risk of overheating. Solar shading proved to be effective during the hottest periods of the year, reducing the risk of extreme overheating by up to 52%

Dynamic model of supercritical Organic Rankine Cycle waste heat recovery system for internal combustion engine

The supercritical Organic Rankine Cycle (ORC) for the Waste Heat Recovery (WHR) from Internal Combustion (IC) engines has been a growing research area in recent years, driven by the aim to enhance the thermal efficiency of the ORC and engine. Simulation of a supercritical ORC-WHR system before a real-time application is important as high pressure in the system may lead to concerns about safety and availability of components. In the ORC-WHR system, the evaporator is the main contributor to thermal inertia of the system and is considered to be the critical component since the heat transfer of this device influences the efficiency of the system. Since the thermo-physical properties of the fluid at supercritical pressures are dependent on temperature, it is necessary to consider the variations in properties of the working fluid. The wellknown Finite Volume (FV) discretization method is generally used to take those property changes into account. However, a FV model of the evaporator in steady state condition cannot be used to predict the thermal inertia of the cycle when it is subjected to transient heat sources. In this paper, a dynamic FV model of the evaporator has been developed and integrated with other components in the ORC-WHR system. The stability and transient responses along with the performance of the ORC-WHR system for the transient heat source are investigated and are also included in this paper