Unit Carbon Emissions Research Articles

Evaluation of thermal insulation capacity and mechanical performance of a novel low-carbon thermal insulating foam concrete

The use of building insulation materials is an effective measure to reduce building energy consumption. To improve the sustainability of insulation materials, desert sand (DS) was used to replace part of the binder, and rice husk ash (RHA) was incorporated to further improve the performance of foamed concrete. The fresh properties, strengths, thermal properties and thermal insulation function of DS-based foamed concrete (DSFC) were systematically investigated. The use of DS and RHA to replace part of Portland cement (PC) and fly ash reduces the flowability of the mixture when the water/binder (PC, fly ash, DS and RHA) ratio is constant. Although the incorporation of DS into foamed concrete increases its density and thermal conductivity, it improves the volume stability of the sample. The strength of specimen with DS decreases due to the low reactivity of DS, which also reduces the content of hydration products. Further incorporation of RHA not only improves the matrix strength by increasing the C-S-H content but also improves the pore structure of the DSFC by increasing the yield stress of the paste. The joint application of DS and RHA effectively reduces the heat storage coefficient and thermal inertia index of DSFC, which is beneficial to improve the thermal insulation capacity of buildings and reduce energy consumption. Incorporating DS and RHA can effectively improve the environmental and economic benefits of the foamed mixture, and the unit strength cost and carbon emission per cubic meter of the 5%–10% RHA-modified samples are reduced by 20.3%–39.1% and 20.2%–38.9%, respectively, compared with the DS35. This research provides a new approach and theoretical basis for building energy saving and external wall insulation.

Green supply chain for steel raw materials under price and demand uncertainty

The scientific formulation of procurement and inventory plans is an important topic in the steel industry, when considering both economic and environmental impacts in an uncertain market environment. Robust optimization methods offer an effective solution to this problem. This study has investigated a multi-echelon and multi-period front-end supply chain centered on a steel enterprise under uncertain purchase prices and demand. The goal is to minimize the costs associated with mining, processing, transportation, procurement, and inventory along with the corresponding carbon emission costs. To address this issue, we present a robust rolling horizon model (RRHM) that considers the inventory capacity constraints of steel enterprise and incorporates ore grade requirements. Subsequently, the RRHM was reformulated into a solvable mixed-integer linear programming model, and the relationship between the robust model and a specific deterministic model was established. Finally, the model was validated by generating instances based on real scenarios. The results demonstrate that the robust rolling horizon model proposed in this paper outperforms both the Sample Average Approximation (SAA) strategy and the (s, S) strategy in terms of cost and robustness. In addition, a sensitivity analysis of the key parameters was conducted. The findings reveal that the unit inventory, mining, and carbon emission costs have a limited impact on the total cost, highlighting the robustness of the model. These findings provide valuable insights into the green and sustainable development of the steel industry, enabling the formulation of effective strategies to mitigate the impacts of uncertainties.

Analysis of standard unit carbon emission and cost assessment of the changing building envelope over material production phase

It is undeniable that the material production stage is crucial to the whole life cycle of structures. This study proposes the window-to-envelope ratio (WER) based on standard units to determine the inherent relationship between changes in door and window areas and carbon emissions, presuming six distinct types of engineering practices for various buildings are selected. It was concluded that larger door and window areas would result in more embodied carbon emissions. Additionally, as the size of windows and doors increases, the costs and embodied carbon of prefabricated and cast-in-place construction become more comparable. According to the analysis, when the building scale is larger and the door and window opening area is also larger, prefabrication has more potential for saving carbon than cast-in-place building, but with a cost of approximately 10–20% higher. Considering the perspective of consumers, producers, and markets, this study revealed a costing assessment methodology based on standard units for prefabricated structures. In this methodology, producers choose and create various residential layouts based on the distinctive requirements of consumers, while tracking the trends in carbon emissions and production costs. This assessment method tries to create a favorable atmosphere for moral market activity and offers an acceptable solution for the trade-off between environmental and economic factors throughout the material production phase of the building.

Dual-drive coordinated operation strategy for internet data centers by exploiting spatiotemporal flexibility

With the rapid expansion of computational infrastructure, the electricity consumption of geographically dispersed Internet Data Centers (IDCs) has imposed a substantial influence on the power grid. Geographically distributed IDCs, which present a versatile electricity demand with significant operational flexibility, hold potential for mitigating cost issues and balancing regional supply and load demand. To exploit this flexibility, this paper has developed a dual-drive coordinated operational strategy, which integrates locational electricity prices and unit carbon emission costs based on the dynamic carbon emission intensity (DCEI) of various regions as interaction signals to improve coordination effectiveness. The upper-level determines the consumption behaviour of IDCs, the lower-level provides feedback on dual-drive signals factoring in IDCs' involvement in grid operation, whilst an iterative algorithm is suggested to solve the bi-level model. Case studies based on real-world datasets demonstrate that the proposed operation strategy can achieve arbitrage through multi-regional carbon-electricity markets, significantly reduce operating costs, and support the rapid development of IDCs. Additionally, this strategy facilitates optimal matching of power load in IDCs with renewable energy sources, thereby mitigating imbalances in regional renewable energy supply and demand.

Are electric vehicles really the optimal option for the transportation sector in China to approach pollution reduction and carbon neutrality goals?

Profound worldwide fleet electrification is thought to be the primary route for achieving the target of carbon neutrality. However, when and how electrification can help mitigate environmental impacts and carbon emissions in the transport sector remains unclear. Herein, the overall life-cycle environmental impacts and carbon saving range of two typical A-class vehicles in China, including electric vehicle (EV) and internal combustion engine vehicle (ICEV), were quantified by the life cycle assessment model for endpoint damage with localization parameters. The results showed that the EV outperformed the ICEV for the total environment impact after a travel distance of 39,153 km and for carbon emissions after 32,292 km. The ICEV was more carbon-friendly only when the driving distance was less than 3229 km/a. Considering a full lifespan travel distance of 150,000 km, the whole life-cycle average environmental impacts of EV and ICEV were calculated as 8.6 and 17.5 mPt/km, respectively, but the EV had 2.3 times higher impacts than the ICEV in the production phase. In addition, the EV unit carbon emission was 140 g/km, 46.8% lower than that of the ICEV. Finally, three potential reduction scenarios were considered: cleaner power mix, energy efficiency improvement and composite scenario. These scenarios contributed 19.1%, 13.0% and 32.1% reductions, respectively. However, achieving carbon peak and neutrality goals in China remains a great challenge unless fossil fuels are replaced by renewable energy. The research can provide scientific reference for the method and practice of emission reduction link identification, eco-driving choice and emission reduction path formulation.

Strategic analysis of green technology unilateral licensing under carbon cap‐and‐trade policy

AbstractWe investigate green technology unilateral licensing strategies between two competing manufacturers under carbon cap‐and‐trade policy. We construct Nash game models and compare the optimal strategies in the unilateral licensing situation with the no‐licensing situation. Comprehensive numerical experiments are taken to investigate the influence of some key parameters on optimal decisions. Our findings show that the green technology unilateral licensing strategy may benefit consumers; when green technology improvement is high, manufacturers tend to take the unilateral licensing strategy to obtain more profits; when initial unit carbon emission difference is moderate or large, the optimal strategy is that the manufacturer with lower level of green technology acts as the licensor; green technology unilateral licensing strategy may not necessarily reduce all manufacturers' total carbon emissions; only when green technology improvement is high, the unilateral licensing strategy is beneficial to environmental protection.

Green Technology Investment Strategies Under Cap-and-Trade Policy

This article aims to address methods for reducing carbon emissions by investigating the green technology investment behavior of enterprises under cap-and-trade regulation and governments’ cap-and-trade policy design mechanisms. Considering that investments are long-term, we developed a two-period green technology investment model for a manufacturing firm facing carbon-sensitive demand in a cap-and-trade regulated market. Our findings show that the firm's investment strategy depends on trade-offs between the gains from selling low-carbon products and the costs of investing in technology. Such trade-offs are affected by consumers’ carbon emissions sensitivity, the unit carbon emission trading price, and the firm's investment efficiency across two periods. The first-period optimal free allowance allocated to the manufacturer is unique, but the second-period optimal free proportion is not unique as it is decided by the unit carbon emission trading price. In addition, the firm's chosen investment strategy based on the optimal carbon policies can create a mutually beneficial situation for the manufacturer, consumers, and society, which shows that the government-designed carbon policies, including the first-period free emissions allowance and the second-period free proportion, are effective. Our study results can aid manufacturers in making wise, strategic, and operational decisions about green technology investment and provide guidance on carbon quota allocation policies that promote the development of low-carbon economies.

The Impact of Carbon Emission Quota Allocation Regulations on the Investment of Low-Carbon Technology in Electric Power Industry Under Peak-Valley Price Policy

This article focuses on carbon emission quota allocation regulations and their impact on investments in low-carbon technology within the electric power industry, as well as other enterprises’ decisions and profits under peak-valley price policy and cap-and-trade mechanism. An electricity supply-chain model is constructed in a Stackelberg game, which comprises an electricity-generating enterprise (leader) and an electricity retailer (follower). The backward-induction method is used to obtain the investment in low-carbon technology and electricity price under three scenarios of carbon emission quota allocation regulations: no regulation, grandfathering allocation, and benchmarking allocation. The main results are: first, benchmarking allocation always results in higher investment in low-carbon technology, but generates greater total carbon emissions than grandfathering allocation under most conditions; and second, under benchmarking allocation, as the unit carbon emission quota increases, total carbon emissions first increase and then decrease. Therefore, benchmarking allocation is the better regulation for the low-carbon technology investment. Moreover, benchmarking allocation is also the better regulation for total carbon emissions with a higher unit carbon quota or a higher carbon price.

Exploration of the effects of electrolytic manganese residue on the environmental, economic, and engineering performance of magnesium oxychloride cement: A possible utilization method of electrolytic manganese residue

The widespread use of magnesium oxychloride cement (MOC) can effectively solve the waste problem in the potash industry. However, its poor water resistance limits its practical application. Electrolytic Manganese Residue (EMR), as a solid waste from manganese metal smelting, requires an effective utilization method. In this work, we have attempted to incorporate EMR into MOC after its treatment in order to improve the water resistance of MOC and increase the utilization rate of EMR. The addition of EMR to MOC increased the density of MOC. The incorporation of EMR did not significantly reduce the strength of the MOC samples. The incorporation of EMR reduced the relative content of magnesium oxide in the specimens and EMR can be used as a source of soluble Al, Si and Fe to produce insoluble amorphous gels. The combined effect resulted in an effective improvement in the water resistance of the samples. The 28-day water immersion strength of the EMR100 can reach 38.3 MPa, and its water resistance coefficient was 82.10%. The appropriate doping of EMR can improve the pore structure of the specimens, reduce the porosity and refine the pore size distribution. Carbon emission per unit compressive strength and cost per unit compressive strength were used as evaluation indices of environmental and economic benefits. A high dosage of EMR-incorporated MOC resulted in low cost and carbon emission, especially the strength of the specimen after water immersion as a strength index. Taking into account the strength after 14 days of air curing and 28 days of water immersion, the advantages of cost per unit compressive strength and carbon emission per unit compressive strength of EMR100 were further extended and reduced by 86.23% and 22.15% respectively compared to the benchmark group. The heavy metal curing of EMR was evaluated by ion leaching test, and the result showed that MOC effectively cured the heavy metal ions in EMR and reduced the environmental risk of EMR. The good performance of EMR in MOC systems not only provides an effective breakthrough for the efficient utilization of EMR and its heavy metal curing, but also effectively improves the performance of MOC and reduces the production cost.

Instability in a carbon pool driven by multiple dissolved organic matter sources in a eutrophic lake basin: Potential factors for increased greenhouse gas emissions

Lakes serve as vital reservoirs of dissolved organic matter (DOM) and play pivotal roles in biogeochemical carbon cycles. However, the sources and compositions of DOM in freshwater lakes and their potential effects on lake sediment carbon pools remain unclear. In this study, seven inflowing rivers in the Lake Taihu basin were selected to explore the potential effects of multi-source DOM inputs on the stability of the lake sediment carbon pool. The results showed the high concentrations of dissolved organic carbon in the Lake Taihu basin, accompanied by a high complexity level. Lignins constituted the majority of DOM compounds, surpassing 40% of the total, while the organic carbon content was predominantly composed of humic acids (1.02–3.01 g kg−1). The high amounts of lignin oxidative cleavage led to CHO being the main molecular structure in the DOM of the seven rivers. The carbon constituents within the sediment carbon reservoir exhibited a positive correlation with dissolved CH4 and CO2, with a notable emphasis on humic acid and dissolved CH4 (R2 = 0.86). The elevated concentration of DOM, coupled with its intricate composition, contributed to the increases in dissolved greenhouse gases (GHGs). Experiments showed that the mixing of multi-source DOM can accelerate the organic carbon mineralization processes. The unit carbon emission efficiency was highest in the mixed group, reaching reached 160.9 μmol∙Cg−1, which also exhibited a significantly different carbon pool. The mixed decomposition of DOM from different sources influenced the roles of the lake carbon pool as source and sink, indicating that the multi-source DOM of this lake basin was a potential driving factor for increased carbon emissions. These findings have improved our understanding of the sources and compositions of DOM in lake basins and revealed their impacts on carbon emissions, thereby providing a theoretical basis for improving assessments of lake carbon emissions.

Life cycle analysis of common landfill final cover systems focusing on carbon neutrality

Carbon emissions from landfill construction and management have become a global concern. Life cycle analysis (LCA) has been widely used to assess the environmental impacts of engineered infrastructures over their lifetimes. LCA has also been applied to landfill leachate and gas management, but rarely to landfill final cover systems. This paper reports the results of an LCA of the following landfill final cover systems: compacted clay cover, geomembrane cover, cover with capillary effects (CCBE), dual capillary barrier cover, three-layer landfill cover system using natural soils, three-layer cover using recycled concrete aggregate (RCA) and biochar-amended three-layer landfill cover system using RCA. The LCA assessment of landfill cover considers the cost, carbon emissions and carbon sequestration during the production, construction and operation phases. The effects of landfill cover on global warming, freshwater eutrophication, terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity and fossil resource scarcity are also evaluated. In addition, the sensitivities of cost and carbon emission to the use of electric-powered machines and transportation distance are analysed. It is revealed that the three-layer cover system using RCA and biochar has the lowest unit cost and carbon emission of all of the covers, up to 88 % and 66 % lower, respectively, than those of the other six covers. In addition, this cover system has the highest carbon sequestration rate, with a value of 47.9 kg CO2/(y·m2), four times higher than that of the compacted clay cover. Finally, this sustainable cover mitigates global warming and reduces adverse environmental impacts by up to 82 %. Therefore, the biochar amended three-layer cover system using RCA without geomembrane offers the greatest economic benefits, performs effectively in terms of the pursuit of carbon neutrality and promotes sustainable development.

Research on the sales mode selection of smart homing firms considering carbon neutrality and digital privacy

Achieving carbon neutrality is the ultimate goal of the global economy. By leveraging Internet of Things (IoT) technology to gather users' data, smart home devices can effectively achieve energy conservation and reduce carbon emissions. The strategic allocation of investment by smart device producers towards environmentally-friendly functionality and choosing the optimal sales mode have emerged as significant research questions. Addressing consumer concerns regarding data privacy sensitivity, this paper presents a game-theoretical model, involving manufacturers, e-commerce platforms, and consumers, to explore the intricate dynamics among investment in smart environmental functionality, sales mode selection, and pricing strategies. The results indicate that manufacturers consistently benefit from such investments. If the number of data-sensitive consumers is considerable, manufacturers will subsidize the platform to encourage the purchase of smart devices, thereby gaining from cross-selling opportunities. When the commission ratio is low, the equilibrium strategy shifts from the agency selling mode to wholesale pricing one, in response to the advent of investments in smart environmental functionality. Furthermore, the commission ratio, consumer perceived environmental value, and unit carbon emissions collectively impact social welfare. This study offers valuable theoretical insights for manufacturers in making informed decisions regarding pricing strategies and sales mode selection, by analyzing the interplay between profit margin and cross-selling income resulting from demand expansion.

Multi-Objective Optimization Method of Industrial Workshop Layout from the Perspective of Low Carbon

A crucial measure to accelerate the low-carbon transformation of enterprises in the industrial sector involves stringent control over carbon emissions attributed to logistics and transportation activities. In this study, a multi-objective workshop layout optimization model is developed, aiming to minimize logistics cost per unit area and carbon emissions, and maximize the non-logistics relationship. The objective is to mitigate avoidable transportation-related carbon emissions during enterprise operations, while facilitating the co-development of the enterprise’s economy and environment. The model is solved utilizing an enhanced NSGA-II algorithm, with the initial solution set optimized through a combination of system layout design method, dynamic adaptive crossover, and variation strategies. Additionally, the distribution function is introduced to enhance the elite retention strategy and boost the algorithm’s search rate. By using an actual case study, the usefulness of the enhanced algorithm is demonstrated, and the plant’s initial low-carbon layout is realized in order to advance the enterprises’ sustainable growth.

Measurement and driving factors of carbon productivity in China's provinces: From the perspective of embodied carbon emissions.

Carbon productivity incorporates economic development and carbon emissions within a unified framework for measuring the economic value per unit carbon emissions. In the context of climate change, improving carbon productivity is of great value for promoting low-carbon development in a country or region. From the perspective of embodied carbon emissions, this study constructs an embodied carbon productivity (ECP) index and uses the Logarithmic Mean Divisia Index decomposition method to study the evolution trends and driving factors of ECP in China's provinces based on China Interregional Input-Output Tables for 2002, 2007, 2012, and 2017. The following results were obtained: First, China's overall ECP showed a continuously increasing trend during the entire period, with the energy efficiency factor playing the largest role among all driving factors. Second, the ECP in 19 of the 30 Chinese provinces continued to increase and the contributions of energy emission ratio, ECP per capita, and population size factors to the increase in ECP presented evident disparities among different provinces. Third, the ECP in three major regions ranged from high to low in the order of East, Central, and West, with the largest growth in the Central, followed by the West, with the smallest in the East. Based on the analysis of research results, we proposed relevant policy recommendations to further improve China's ECP and achieve low-carbon economy.

How does blockchain technology affect the strategic financing decisions of platform supply chain with low-carbon product?

PurposeTo explore how the blockchain affects the pricing and financing decisions in a low-carbon platform supply chain.Design/methodology/approachConsidering the dual roles of the e-commerce platform as a seller and an initiator, a typical game-theoretical method is applied to analyze the behavior of supply chain decision-makers and the impact of key variables on equilibriums.FindingsWhen loan interest rates are symmetric, whether blockchain is used or not, the e-commerce platform financing mode will always produce higher wholesale price and unit carbon emission reduction, while the retail price is the opposite. Higher unit additional income brought by the blockchain can bring higher economic and environmental performances, and the e-commerce platform financing mode is superior to bank financing mode. The application of blockchain may cause the manufacturer to change his/her financing choice. For bank financing, with the increase of loan interest rates, the advantages brought by blockchain will gradually disappear, but this situation will not occur under e-commerce platform financing.Originality/valueBlockchain is known for its information transparency properties and its ability to enhance user trust. However, the impacts of applying blockchain in a low-carbon platform supply chain with different financing options are not clear. The authors examine the manufacturer's strategic choices for platform financing and bank financing, whether to adopt blockchain, and the impact of these decisions on carbon emissions reduction, consumer surplus and social welfare. The research conclusion can provide reference for the operation and financing decisions of platform supply chain under the carbon reduction target in the digital economy era.

Production and decarbonisation of conventional gasoline vehicle automakers under subsidy and regulation policies

ABSTRACT Decarbonising the transportation sector through electrification is critical to reducing greenhouse gas emissions. To explore the decarbonisation of conventional gasoline vehicle (GV) automakers in GV and/or electric vehicle (EV) production, we develop analytical models under pure subsidy, pure regulation, and hybrid subsidy-regulation policies. We first examine the monopoly GV automaker’s EV market entry intention in each policy and find that it always increases with consumer range sensitivity and subsidy/regulation parameters, but decreases with product substitutability between the two vehicles. Then, we analyse the implication of policy changes on equilibrium outcomes. Our results show that although introducing regulations and removing subsidies have opposite effects on optimal production and driving range decisions, both might stimulate or restrict the GV automaker to decarbonise, depending on the unit carbon emissions of GVs and EVs. Finally, we extend the monopoly model to the duopoly case, showing that while entering the EV market hurts the EV automaker, it allows the GV automaker’s carbon emissions to always decrease with GV credit coefficients. Together with sensitivity analyses on key parameters, our findings provide insights not only for GV automakers to respond to policy changes but also for governments to design incentives for EV diffusion.

Environmental life cycle assessment of bridge deck pavement and case studies of two bridges in China

The durability of deck pavement material has great impact on deck performance and carbon emission. This paper aims to analyze the durability of different deck pavement materials and structures by taking two bridges across the Yangtze River in China as examples, and establish the carbon emission model of the bridge deck pavement during the whole life cycle. The carbon emissions of the two bridges during twenty years of service are then calculated based on the model. It can provide reference for future bridge deck pavement schemes and measures to reduce carbon emissions. In this paper, two typical representative bridges in Jiangsu Province in East China are selected for case analysis, namely the Jiangyin Yangtze River Highway Bridge and the Second Nanjing Yangtze River Bridge. Firstly, this paper introduces the specific forms of various bridge deck pavement schemes since the construction of the two bridges. After many years of experiments, the pavement of the Jiangyin Yangtze River Highway Bridge has changed from mastic asphalt mixture to double-layer hot mix epoxy asphalt concrete, and that of the Second Nanjing Yangtze River Bridge has changed from warm mix epoxy asphalt to hot mix epoxy asphalt. Focusing on the carbon emission of bridge deck pavement, the carbon emission model of different asphalt mixture pavements based on life cycle assessment (LCA) is established. The assessment can be divided into five stages: material production, transportation, construction, maintenance and demolishment. This paper takes extra traffic congestion during repair and maintenance into consideration. In this paper, two bridges were taken as cases to calculate the carbon emission. In initial construction, the deck of the Jiangyin Yangtze River Highway Bridge was paved with mastic asphalt mixture; while the deck of the Second Nanjing Yangtze River Bridge was paved with epoxy asphalt concrete. The paving material of the Jiangyin Yangtze River Highway Bridge was changed into epoxy asphalt concrete gradually in repair and maintenance. The analysis results show that in the initial 20 years of life, considering the initial construction and major maintenance of deck pavement, the total carbon emission of the Jiangyin Yangtze River Highway Bridge and the Second Nanjing Yangtze River Bridge is 179,195 kg CO2e and 101,577 kg CO2e respectively. The unit carbon emission of the Jiangyin Yangtze River Highway Bridge after 20 years of opening to traffic is 5.079 kg/m2 CO2e. The proportions of the five stages were 76.4 %, 2.7 %, 2.5 %, 16.8 % and 1.6 %, respectively. The unit carbon emission of the Second Nanjing Yangtze River Bridge after 20 years of opening to traffic is 3.352 kg/m2 CO2e. The proportions of the five stages were 66.3 %, 2.4 %, 2.6 %, 28.2 % and 0.6 %, respectively. The results show that epoxy asphalt material has better durability and can reduce carbon emission of bridge deck pavement.

Live streaming platform operations and coordination under the cap-and-trade regulation: Platform-enabled mode versus platform-agency mode

We consider a supply chain consisting of a supplier and a manufacturer where the manufacturer sells its products directly or through a live streaming platform (LSP). Operating in either the platform-enabled and platform-agency mode under the cap-and-trade regulation, the platform has platform power that reflects its ability to expand the market size. We find that the optimal production quantity in the platform-agency mode may decrease with the cap and platform power. The supplier and manufacturer can always be coordinated under the wholesale price contract in the platform-enabled mode. However, in the platform-agency mode, the two firms can be coordinated under low or high platform power, but whether coordination is achieved under moderate platform power depends on the unit carbon emissions of the products. If the platform power is low or high, the platform-enabled mode yields more total production quantity; otherwise, the platform-agency mode yields more total production quantity. Whether the platform-enabled or platform-agency mode generates a higher profit for the manufacturer highly depends on the promotion cost. By considering product investment and sales effort, we find the following: (i) When considering product investment, the supplier and manufacturer cannot be coordinated under the wholesale price contract in either mode. (ii) When considering sales effort, the firms can be coordinated in the platform-enabled mode, while in the platform-agency mode, whether they can be coordinated under the wholesale price contract depends on the cost coefficient and the unit carbon emissions of the products.

Energy Efficiency Assessment of Industrial Users Based on Improved TOPSIS Grey Correlation Analysis

In order to improve the energy efficiency of industrial users and evaluate the energy efficiency level before optimizing the energy efficiency of enterprises, an energy efficiency evaluation method based on improved TOPSIS grey relational analysis was proposed to find the weak links in energy use. Firstly, three indexes of energy stability, energy consumption per unit output and carbon emission per unit output are selected to construct the energy efficiency index system. Secondly, the index weights are calculated by entropy weight method, and the energy efficiency levels of industrial users are classified, which can be used by the power grid to implement differentiated electricity prices for high-energy consumption enterprises. Last example city 10 typical energy-intensive enterprise users used improved TOPSIS grey correlation analysis method for evaluation of energy efficiency, energy consumption per unit output value is obtained by analysis of the index weight is the largest, the better the performance of the index, the higher the comprehensive evaluation results of energy efficiency, and finally the method compared with other evaluation methods to verify the effectiveness of the proposed method in this paper.

Pricing and carbon reduction strategies for vertically differentiated firms under Cap-and-Trade regulation

This paper develops a price and low-carbon competition model for two vertically differentiated firms, a high-quality manufacturer (HM) and a low-quality manufacturer (LM), with consumers who prefer low-carbon products. The implementation of the cap-and-trade regulation (CATR) by the government is essential for the carbon trading market where firms can choose to buy (resp., sell) carbon quota when the unit carbon emission reaches above (resp., below) the allocated quota. An investigation is conducted into how the pricing and carbon reduction rate (CRR) of manufacturers would be affected by the CATR and low-carbon preference of consumers. In the absence of CATR, price and CRR always show a positive correlation for a manufacturer. However, under the CATR, hiking price is not necessarily the best choice for the manufacturer when the CRR is increased. Furthermore, contrary to the conventional wisdom, we demonstrate that in order to motivate manufacturers to increase CRR, the government should increase the unit carbon quota rather than reduce it. Moreover, it is demonstrated in this paper that the enforcement of the CATR does not necessarily result in a higher CRR, a lower total carbon emission, or higher social welfare. The government should be mindful in designing the CATR and choosing the unit carbon quota to achieve the desired outcome.