• Energy Research
• 11. Sustainability close
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Abstract Over the recent decades, China’s building energy consumption has been growing rapidly. Also the fuel mix has been changing quickly with more natural gas & electricity and less coal being used. Meanwhile, the technologies used in building sector are improving in efficiency. In this paper, the impact of technical progress and the use of renewable energy in building sector are analyzed. The energy saving and emission reduction potential of building sector are also measured. China TIMES model is used to model the future energy consumption and carbon emissions in building sector. The modelling results indicate that building energy consumption is expected to grow to around 41.6EJ in the reference scenario in 2050. The energy saving potential in 2050 can be up to 4EJ due to the improvement of both building insulation (envelop) and energy use technologies. Renewable energy used in buildings can be a great contributor to the carbon mitigation in buildings. China’s building sector can reach a relatively low-carbon future with more low- and non-carbon fuels consumed.

Climate change present a range of equity issues for human being, but operating the equity principle within emission allocation scheme to various parties has raised multiple challenges. Although more than 40 schemes have been suggested in the literatures, there is little consistency in the way that baselines, scope, coverage and other key parameters have been compared or discussed. In this paper, we reviewed 41 schemes used in the literature so far and compared the cumulative allowances of main countries under various schemes in a consistent framework. Two cases are considered, i.e. only energy and industry related CO2 and all Kyoto GHGs. Besides the allowances, carbon Gini coefficient in the global perspective and the reduction tradeoffs between country groups are further quantitatively discussed. It is demon- strated that the full ranges of countries' allowances are quite large resulting from different equity consid- erations and implement methods behind different effort-sharing schemes. However, absolute mitigations are always required in developed countries in order to realize the 2 C target, regardless of schemes.

The ten countries that joined the European Union (EU) in 2004 (Cyprus, Czechia, Estonia, Hungary, Lithuania, Latvia, Malta, Poland, Slovakia, and Slovenia) have experienced faster economic growth and slower declines in energy consumption than traditional EU members. As designing of low-carbon policies requires accurate CO2 emission accounting, this study describes the evolving trajectories of CO2 emissions from 2005 to 2017 of 2004 EU accession members by providing detailed emission inventories by 28 types of energy and 47 socioeconomic sectors. We further quantify the contributions of four socioeconomic drivers (i.e., economic growth, energy structure, carbon intensity, and energy intensity) to the emission changes. The results show that the total CO2 emissions of the ten countries decreased by 7.50% from 2010 (506.81 Mt) to 2016 (468.78 Mt), which is lower than the average decline rate of other EU members (10.52%). Although the effect of economic growth contributed the most to emission increase (15.44%), it is completely offset by the decline in carbon intensity (-18.82%). We also discuss potential roadmaps towards carbon neutrality by designing 33 scenarios based on the European Union Low-Carbon Development Map 2050. We find that carbon neutrality cannot be achieved unless the share of renewable energy sources reaches 60% and more than half of existing coal and gas power plants are upgraded to Carbon Capture Storage (CCS) technology. These changes require the implementation of both short-term and long-term strategies.

Meteorological measurements are conducted in Antwerp, Belgium in July 2013, followed by CFD urban microclimate simulations considering the same city and time period. The simulations are found to be able to reproduce measured air temperatures inside central Antwerp with an average absolute difference of 0.88 °C. The simulation results supplemented with measurements are used to generate location-specific Microclimatic Conditions (MCs) in three locations: (1) a rural location outside Antwerp; (2) an urban location inside Antwerp, away from an urban park; and (3) another urban location, close to the same park. Building Energy Simulations (BES) are performed for 36 cases based on three different MCs, two building use types and six sets of construction characteristics, ranging from pre-1946 buildings to new, low-energy buildings. Monthly Cooling Demands (CDs) are extracted for each case and compared with each other. The results demonstrate that compared to the air temperatures in the rural area, on average, air temperatures at the urban sites away and close to the park are 3.3 °C and 2.4 °C higher, respectively. This leads to an additional monthly CD of up to 90%. CDs of buildings with better thermal insulation and lower infiltration rates can increase by 48% once moved from the rural location to an urban location, which may lead to the reconsideration of design guidelines of low-energy buildings exposed to an urban MC. Although the proximity of an urban park cannot fully compensate the increased CD by an urban MC, residential buildings close to the park are found to have on average 13.9% less CD during July 2013, compared with buildings away from the same park. The influence of the urban park on the CDs of buildings in its vicinity is strongly linked to the meteorological wind direction. Professionals focusing on energy-efficient buildings in cities are advised to conduct energy predictions with location-specific MC data, instead of only using city-averaged meteorological data.

Abstract BackgroundAccording to sustainable development goals (SDGs), societies should have access to affordable, reliable, and sustainable energy. Deregulated electricity markets have been established to provide affordable electricity for end-users through advertising competition. Although these liberalized markets are expected to serve this purpose, they are far from perfect and are prone to threats, such as collusion. Tacit collusion is a condition, in which power generating companies (GenCos) disrupt the competition by exploiting their market power. MethodsIn this manuscript, a novel deep Q-network (DQN) model is developed, which GenCos can use to determine the bidding strategies to maximize average long-term payoffs using available information. In the presence of collusive equilibria, the results are compared with a conventional Q-learning model that solely relies on past outcomes. With that, this manuscript aims to investigate the impact of emerging DQN models on the establishment of collusive equilibrium in markets with repetitive interactions among players. Results and ConclusionsThe outcomes show that GenCos may be able to collude unintentionally while trying to ameliorate long-term profits. Collusive strategies can lead to exorbitant electric bills for end-users, which is one of the influential factors in energy poverty. Thus, policymakers and market designers should be vigilant regarding the combined effect of information disclosure and autonomous pricing, as new models exploit information more effectively.

Abstract Land use patterns may affect carbon emissions in the urban transition process. However, land and carbon issues are often considered as isolated factors when mitigating urban carbon emissions. In this study, we proposed a spatial land-carbon nexus framework for exploring the interwoven connections of carbon emission and land-use changes. The land-related carbon transitions were accounted by the land-use conversion matrix and carbon transfer density. Then, the ecological relationships among various land-use changes were explored using ecological network analysis (ENA). A land-carbon nexus rate was proposed to depict the integrated effect of land-use changes on carbon balance. A case study was also conducted for cities in Zhejiang Province during the periods of 1995–2000, 2000–2005, 2005–2010 and 2010–2015, showing their positive and negative land-related carbon transitions, and the variations of ecological relationships as well. The results showed that: (1) The dominant negative and positive carbon transitions exhibited in land-use changes from CL (Cultivated land) to I&T (Indusial and Transportation land) and I&T to CL. (2) Spatially, natural land-use type including wetland and forest exhibited competition relationships in the urban fringe area, while others embracing I&T and UCL (Urban construction land) with mutualism relationships scattered in the central urban area. (3) The dominate driving weight contributions for 8 cities were transformed from CL to I&T from 1995 to 2015, whereas the major pulling force weight contributions were always induced by natural land-use types with carbon sequestration functions. The land-carbon nexus approach presents great potential for bridging nexus analysis with resilient spatial planning to reduce the pressure in support of low carbon transitions through urban land management.

The use of electric vehicles is being promoted to address emerging concerns about global warming associated with emissions from fossil fuels. Besides, in the context of parcel delivery deep growth related to e-commerce, electric vehicle is becoming an alternative to conventional fossil fuel technology. Intrinsically, the charging process implies the interdependence between the transportation and electric power systems. This paper presents a new multistage optimization-based approach that allows linking delivery routing and aggregated demand management in the transportation and electric power systems, respectively. For the routing and charging of each independent electric vehicle, battery degradation, acceleration- and speed-dependent power consumption, penalty for delivery delay, tolls, fixed charging prices and incentives for availability time are considered. An electric vehicle demand aggregator is used to guarantee the synergy between systems. Incentives are included to motivate electric vehicles to remain at charging intersections. However, attractive incentives can create electric power system congestion due to simultaneous charges on nodes. Thus, an iterative decongestion methodology is developed. The resulting model is divided into three stages: delivery allocation, delivery routing for each

Abstract The issue of climate change and the development of international agreements around carbon targets such as the Paris agreement have engendered the prospect of a carbon constrained future. As a result, individual nations who are signatory to the Paris Agreement have developed ambitious carbon reduction targets in order to restrict temperature rises to two degrees Celsius compared to pre-industrial levels. To achieve these ambitious goals, nations have a variety of policy approaches at their disposal including feed in tariffs, fossil fuel restrictions, carbon capture and storage, renewable portfolio standards and carbon trading regimes. This study investigates carbon trading, and, using Japan as a case study assesses the economic feasibility and environmental efficiency of a carbon trading scheme underpinned by renewable energy deployment. The model employed uses an optimization approach, cognizant of technological, geographic and economic constraints. Findings identify that such an approach incorporating the 47 prefectures of Japan could engender a 42% reduction in emissions without resilience constraints and 34% incorporating a best-mix, resilient approach. Both approaches prove feasible at moderate carbon prices, considering international norms. The findings underpin policy implications for a future national Japanese emission trading scheme to improve previous single prefecture attempts which did not engender carbon trading.