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Achieving the low-carbon transition of power systems requires the coordination of renewable energy generation and other emerging electricity technologies. Their technical indicators are changing rapidly since these technologies are in the initial stages of development. Determining the technical and policy targets for achieving the low-carbon transition is critical for regulators and power system planners. This paper defines this problem as a backcasting problem, whose concept is derived from environmental science research. We introduce it into the power system planning field and innovatively model it as a bi-level optimization problem. According to the characteristics of the backcasting problem, an improved barrier method is proposed to solve it efficiently. The effectiveness of the proposed model and algorithm are verified through case studies on a modified Garver’s 6-bus system and a realistic Northwest China power system, and they are compared with state-of-the-art solution techniques. The results of the backcasting problem provide a new perspective on the economic impacts of the low-carbon transition and are helpful in energy policy formulation for power systems. [ABSTRACT FROM AUTHOR]

Regarding the continuing increase of anthropogenic carbon emissions in the power system with growing energy consumption, researchers have focused on managing the demand side to achieve low-carbon transition. However, such a low-carbon transition cannot be achieved effectively without the proper incentive scheme. Moreover, it is desired to improve the computation quality of carbon tracing tools and extend their applications by state-of-art techniques. To fulfil these existing research gaps, this paper proposes a low-carbon optimal scheduling model with demand response (DR) based carbon intensity control. It aims to reduce the dependence of customers on energy sources with high carbon intensities while decreasing reasonable energy consumption. Likewise, a data-driven approach conducted with the Bayesian interfere regression is proposed to carry out the carbon emission flow (CEF) model to cope with the drawbacks of the conventional emission calculation. Moreover, the storage emission and relevant dynamic impacts to the system are fully considered. The proposed data-driven approach is tested on a series of IEEE systems with different sizes, its high accuracy and efficiency are proved by the simulation results. Further, simulation results indicate that the proposed scheduling model can effectively achieve carbon emission mitigation. [ABSTRACT FROM AUTHOR]

Globally, the efficiency of industrial motors is regulated through minimum energy performance standards (MEPS) to reduce energy consumption and CO2 emission. Induction motor, used as a representative industrial motor, has a limit to efficiency improvement as the result of the additional copper loss of the rotor. To replace the induction motor, design of synchronous reluctance motor (SynRM) and permanent magnet assisted synchronous reluctance motor (PMa-SynRM), and the application of a small amount of permanent magnet, is actively studied in the industry. However, it is necessary to develop an ultrapremium efficiency motor beyond the superpremium efficiency to fulfill MEPS, which will be strengthened in the future. Therefore, this paper presents the optimal design method of SynRM by using the finite element method and response surface method to achieve superpremium efficiency. Furthermore, the redefinition of the loading ratio with shape parameters, and the design method of PMa-SynRM, using the loading ratio, is proposed to meet the ultrapremium efficiency. It is an effective design method that can shorten the time and process when designing ultrapremium efficiency PMa-SynRM from the existing SynRM, which is already mass-produced. [ABSTRACT FROM AUTHOR]

To contribute to a smart grid, the unit commitment and dispatch (UCD) is a very important problem to be revisited in the future microgrid environment. This paper studies the UCD problem by taking account of both traditional thermal units and distributed generation units while considering demand response and carbon emissions trading. First, the UCD problem is reformulated as an optimal switching problem of a hybrid system. The reformulation allows for convenient handling of time-dependent start-up cost by dynamic programming. Then, we propose a closed-loop hierarchical operation (CLHO) algorithm, which produces the optimal schedule with a closed-loop feature. Theoretical analysis shows the equivalence of the reformulation and the effectiveness of the CLHO algorithm. Finally, the closed-loop feature and the effectiveness of the proposed algorithm are further verified by simulations. The simulations also show that low emission allowance and high emissions trading price can reduce the total carbon emissions. [ABSTRACT FROM AUTHOR]

The Vostok ice core provides measurements of the CO2 concentration during the last 414 x 10³ years (yr). Estimations of power spectra show peaks, with the strongest one corresponding to a time period of around 100 x 10³ yr. In this paper, a new reconstruction method from irregular sampling is used, allowing more accurate estimation of spectral peaks. This method intrinsically decomposes the analyzed signal as a sum of sines, providing amplitudes but also phase measurements of periodic tendencies (due to the nature of the studied phenomena). This decomposition can be conducted with noisy and inaccurate measurements of the sampling instants and the concentrations. The widely used Vostok data were chosen as an example, but the method could also be applied to data from other places (e.g., dome C, Antarctica) or to study other phenomena as nitrogen dioxide NO2, methane CH4, oxygen isotope 18O (closely linked to temperature), deuterium ²H, or dust concentrations. [ABSTRACT FROM AUTHOR]

This paper investigates the dynamic dielectric recovery synergy (DDRS) of hybrid circuit breakers (HCBs) with CO2 gas and vacuum gaps in series. The interaction between the vacuum arc and CO2 gas arc is simulated by the continuous transient arc model and Mayr arc model. The simulation results indicate that the extra methods, for example, dividing capacitors, are needed to obtain optimal DDRS of HCB. The prototype of HCB and the test circuit are established. The influence of the coordination of arcing time, dividing capacitors, and the CO2 gas pressures on the transient recovery voltage (TRV) distribution and the breaking capacity is investigated. The differences of HCBs with SF6 gas and CO2 gas are also compared. According to the results, favorable DDRS in HCB can be obtained in the condition that the vacuum gap endures the initial TRV while the following major TRV distribution is mainly depended on the dynamic dielectric in CO2 gas gap. However, the dynamic dielectric recovery of CO2 gas gap is limited by the structure of rotating arc CO2 gas interrupter in this paper. In the future, the interruption capacity of HCB based on CO2 gas can be improved by synergy control, as the development of CO2 gas circuit breakers. [ABSTRACT FROM PUBLISHER]

This paper investigates the AC insulation properties and explores the influence of electric field inhomogeneity on the breakdown voltage of HFO-1336mzz(E)/CO 2 gas mixture. The electrical field sensitivity of HFO-1336mzz(E)/CO 2 and SF 6 is further compared. It is found that the insulation performance of HFO-1336mzz(E)/CO 2 mixture with 25–30% HFO-1336mzz(E) can reach up to 75-85% of SF 6 under the quasi-uniform electric field and there is a favorable positive synergistic effect between HFO-1336mzz(E) and CO 2. The breakdown voltage of HFO-1336mzz(E)/CO 2 gas mixture demonstrates a “hump” effect with gas pressure under the highly non-uniform electric field and its sensitivity to the electric field inhomogeneity is significantly lower than that of SF 6. The insulation performance of HFO-1336mzz(E)/CO 2 with HFO-1336mzz(E) content higher than 20% reaches 0.99–1.05 times that of SF 6 under highly non-uniform electric field. The AC breakdown voltage of HFO-1336mzz(E)/CO 2 gas mixture and SF 6 decreases first and then increases with the electric field inhomogeneity (f), demonstrating a “U-shaped” like curve and finally tends to be stable. The related results of this paper systematically reveal the AC insulation properties of HFO-1336mzz(E)/CO 2 gas mixture and provide an important reference for its engineering application. [ABSTRACT FROM AUTHOR]

The research on characteristics of C 4 F 7 N and epoxy resin insulation system affected by long-term electro-thermal accelerated aging can provide the reference for the application of C 4 F 7 N/CO 2 gas mixtures. In this paper, a long-term electro-thermal accelerated aging experimental platform of gas-solid insulation system is established, and more than 3000 hours of experiments are carried out. The results show that there is not a significant change in leakage current in the system, at the same time, none of the gas decomposition products are detected in the C 4 F 7 N/CO 2 gas mixtures during the aging experiment. With the increase of aging experiment time, the number of tiny holes on the epoxy resin surface increases significantly. The surface of the epoxy resin sample near the high voltage electrode is most obviously damaged. The surface of epoxy resin shows slightly fluorinated, and the color of it has changed from white to yellow on account of the adsorption of C 4 F 7 N gas by the holes on the sample surface. Flashover voltage of epoxy resin is basically consistent before and after aging by the power frequency or negative lightning impulse applied. It proves that the gas-solid insulation system of C 4 F 7 N and epoxy resin can keep the insulation performance basically consistent, affected by longterm electro-thermal accelerated aging. [ABSTRACT FROM AUTHOR]

In this paper, we report the vertical profiles of CO2 and CH4 measured with a cavity ring-down spectrometer (CRDS) on a research aircraft from near-ground level to 8 km above mean sea level. The airborne platform employed in this paper is an Alpha Jet aircraft operated from NASA's Ames Research Center. Flights were undertaken to Railroad Valley, NV, USA, to coincide with overpasses of the Greenhouse Gases Observing Satellite (GOSAT). Ground-based CO2 and CH4 were simultaneously measured using CRDS, at the time and location of the airborne and satellite measurements. Results of three GOSAT coordinated aircraft profiles and ground-based measurements in June 2011 are presented and discussed in this paper. The accuracy of the CO2 and CH4 measurements has been determined based upon laboratory calibrations (World Meteorological Organisation traceable standard) and pressure/temperature flight simulations in a test chamber. The overall uncertainty for the airborne measurements ranged from 0.31 to 0.39 ppm for CO2 and from 3.5 to 5.6 ppb for CH4. Our column-averaged CO2 and CH4 measurements, which include about 61% of the total atmospheric mass, are extrapolated, using different techniques, to include the remainder of the tropospheric and stratospheric CO2 and CH4. The CO2 data are then analyzed using the Atmospheric CO2 Observations from Space 2.9 and 3.3 algorithms. For methane data, the RemoTeC v2.1 algorithm was used in its full physics setup. Column-averaged CO2 and XCO2, measured by GOSAT and analyzed from our data, ranged from 388.1 to 396.4 ppm, and XCH4 ranged from 1.743 to 1.822 ppm. The agreement of the satellite and aircraft CO2 mixing ratios, as well as ground measurements, falls within the uncertainties of the methods employed to acquire these numbers. [ABSTRACT FROM PUBLISHER]

Regarding carbon emission as a principal cause of global warming, governments begin to take note of the urgency of emission reduction and propose feasible carbon regulations. Consumers also become more caring about the carbon emission factor when purchasing product. In response, the firms have exerted considerable efforts to reduce their emissions. In this paper, we investigate a supply chain facing carbon-sensitive demand market. Two major carbon regulations, absolute-cap (AC) and intensity-cap (IC), are considered. We explore the optimization problems for the centralized and decentralized models, and derive the optimal solutions for the production quantity as well as the emission reduction effort. We find that under regulation IC, a higher emission cap will lower the carbon emission of unit product but raise the total production quantity, while the emission cap is irrelevant to these operational decisions under regulation AC. In addition, the production quantity and the emission reduction effort under regulation AC are lower than those under regulation IC. We further show double marginalization within this supply chain manifests as not only a lower production quantity but also a higher unit carbon emission. Finally, numerical experiments are conducted to obtain more insights. [ABSTRACT FROM AUTHOR]

This paper is focused on carbon coating of anatase type TiO2 by underwater discharge with a capillary in water carbon electrode. The discharge electrode consists of a graphite electrode covered by an alumina tube for insulation and a ground electrode. The aqueous solution used for discharging is tap water with an electric conductivity of about $120~\mu \text{S}$ /cm. The applied power for TiO2 carbon coating is about 500 W. As a result of TEM and energy dispersive spectrum measurements, a carbon layer with thickness of several nanometers was measured on the surface of TiO2. Raman analysis also confirmed that the layer is either graphite or glassy carbon. [ABSTRACT FROM AUTHOR]

This paper presents a density functional theory-based first principle study to investigate the atomic-scale interactions of formaldehyde (H2CO) molecules with different oxygen containing functional groups of graphene oxide to identify which particular functional group possesses better adsorption capability toward H2CO molecule. The detailed study on formaldehyde adsorption has been conducted in terms of changes in structural, energetic, electronic, and transport properties of graphene oxides modeled with sp3 hybridized hydroxyl (-OH) and epoxy (C-O-C) groups on the carbon basal plane. Our computational results suggest that the graphene oxidized with only -OH group shows the highest affinity toward formaldehyde as compared with epoxy oxidized graphene and graphene oxide containing both the functional groups. The influence of vacancy defect on improving the sensing response of graphene oxide has also been studied. The results of current–voltage (${I}$ – ${V}$) characteristics reveal that graphene oxidized with only hydroxyl group can achieve an improvement in sensitivity by almost two times and five times as compared with graphene oxide containing both the functional groups and the pristine graphene sheet, respectively. Moreover, the selectivity test for some common indoor air pollutants was also carried out and the test results suggest that H2CO molecule is highly selective toward the -OH group of graphene oxide as compared with the epoxy group. [ABSTRACT FROM AUTHOR]

This paper presents a new method for quantifying the carbon storage in urban trees using multispectral airborne laser scanning (ALS) data. This method takes the full advantage of multispectral ALS range and intensity data and shows the feasibility of quantifies the carbon storage in urban trees. Our method consists of four steps: multispectral ALS data processing, vegetation isolation, dendrometric parameters estimation, and carbon storage modeling. Our results suggest that ALS-based dendrometric parameter estimation and allometric models can yield consistent performance and accurate estimation. Citywide carbon storage estimation is derived in this paper for the Town of Whitchurch–Stouffville, Ontario, Canada, by extrapolating the values within the study area to the entire city based on the specific proportion of each land cover type. The proposed method reveals the potential of multispectral ALS data in land cover mapping and carbon storage estimation at individual-tree level. [ABSTRACT FROM AUTHOR]

The acceleration of distributed energy resources and carbon pricing policies have compelled utilities to act and to prioritize carbon-constrained infrastructure augmentation in their capital programs. To implement various carbon emission reduction policies, power system transmission planning has become more challenging. The existing energy system will face massive retirement of coal-fired power plants (CFPPs), large scale integration of renewable energy and network expansion. In this paper, an electricity network planning and transformation roadmap, which has two milestones, is put forward. In the first stage, a mathematical model is proposed based on the average cost of carbon emission reduction to realize the cooperation of CFPPs retirement and renewable energy investment. It can help the network carry out the transition from a fossil-fuel dominated system to a low-carbon oriented system. Because of the promising prospect of power-to-gas (P2G) technology, in the second milestone, a method based on carbon emission flow (CEF) is employed to help the power-to-gas stations (P2GSes) to select the construction site and capacity. The gas network constraints are modeled to guarantee that P2GSes can work smoothly without energy flow congestion in both electricity and gas networks. According to the simulation results in case studies, our method can reach the emission reduction target more economically and effectively, and the P2GSes can produce and absorb clean energy. [ABSTRACT FROM AUTHOR]

The increasing penetration of electric vehicles (EVs) results in growing interdependency between power and transportation networks. This paper proposes a hybrid economic-emission dispatch model to coordinate the operation of both networks toward social optima. Specifically, carbon emission from gasoline vehicles (GVs) is quantified by the macroscopic emission model, while the emission from EVs is indirectly characterized by that emitted from fossil power plants. To enhance regulation efficiency and improve social welfare, a differentiated pricing scheme is proposed to independently regulate GV traffic flow, EV traffic flow, and EV charging flow. Logarithmic transformation, combined with an accuracy-aware adaptive piecewise linearization (AAPWL) approximation method, is developed to reformulate the original nonlinear model into a tractable mixed-integer quadratic constrained programming. Numerical results from two test systems demonstrate the relationship between economic dispatch and emission dispatch. Meanwhile, the effectiveness and superiority of the proposed pricing scheme and the AAPWL method are validated. [ABSTRACT FROM AUTHOR]

Due to the development of the green economy, green manufacturing has been a hot topic. This paper proposes a new problem, i.e., the resource constrained unrelated parallel machine green manufacturing scheduling problem (RCUPMGSP) with the criteria of minimizing the makespan and the total carbon emission. To solve the problem, a collaborative multiobjective fruit fly optimization algorithm (CMFOA) is proposed. First, a job-speed pair-based solution representation is presented, and an effective decoding method is designed. Second, a heuristic for initialization of the population is proposed. Third, three collaborative search operators are designed to handle three subproblems in the smell-based search phase, i.e., job-to-machine assignment, job sequence, and processing speed selection. The technique for order preference by similarity to an ideal solution and the fast nondominated sorting methods are both employed for multiobjective evaluation in the vision-based search phase. Moreover, a critical-path-based carbon saving technique is designed according to the problem analysis to further improve the nondominated solutions explored in the fruit fly optimization algorithm-based evolution. In addition, the effect of parameter setting is investigated and the suitable parameter values are recommended. Finally, numerical tests and comparisons are carried out using the randomly generated instances, which show that the CMFOA is able to obtain more and better nondominated solutions than other algorithms. The comparisons also demonstrate the effectiveness of the collaborative scheme and the carbon saving technique as well as the CMFOA in solving the RCUPMGSP. [ABSTRACT FROM AUTHOR]

This paper represents the prediction of the thermal interruption characteristics of a 72.5-kV CO2 circuit breaker (CB). An analysis method to simulate CO2 arc plasma was developed. The principle phenomena of CO2 arc plasma—nonideal gas behavior, radiative heat transfer (RHT), and nozzle ablation—were considered. In addition, the electric field analysis to compute ohmic heating in the arc region and the analysis of turbulent flows were conducted. The absorption coefficients used in RHT were simplified into mean values of 10 frequency bands to represent the entire absorption spectrum. The proposed method was verified through experimental tests of pressure rise and arc voltage. To predict the thermal interruption characteristics, post arc current (PAC) was computed. PAC is the minute current existing between the contacts of a CB after current zero, and has important value to comprehensively understanding thermal interruption. For comparison, a 72.5-kV CO2 CB was manufactured and tested, and the results were compared with the results of the thermal interruption tests. [ABSTRACT FROM AUTHOR]

Most existing carbon emission management strategies only control the total carbon emission without focusing on both the regional carbon emission and the stochastic properties of the system. Correlated regional loads and unpredictable renewable energies in the power system make regional carbon emission management (RCEM) increasingly challenging and necessary. A complex multi-objective RCEM model based on probabilistic power flow (PPF) considering correlated variables is contributed in this paper. The three objective functions to be minimized are 1) the cost of electricity generated, 2) the total carbon emission, and 3) the carbon emission difference among regions which reflects the regional carbon emission imbalance from the supply side. A new clonal selection algorithm (CSA) coupled with a fuzzy satisfying decision method and an extended 2 m +1 point estimate method (PEM) is proposed to solve this multi-objective RCEM model. The proposed method is illustrated through IEEE 30-bus, IEEE 118-bus and simplified Shanghai case studies. The proposed model can help reduce the total carbon emission, control regional carbon emission, prevent probabilistic congested lines from overloading, and choose the most suitable region for wind farms (WFs). [ABSTRACT FROM PUBLISHER]

This paper presents a study on outgassing and electrical conditioning for three carbon fiber cathode types in a vacuum-sealed, high-power microwave virtual-cathode-oscillator (vircator) that operates in the low \(10^{-9}\) torr pressure regime. The three cathode types consist of a bare bimodal fiber structure, a bare unimodal fiber structure, and a cesium-iodide coated bimodal fiber structure with identical fiber coverage of 2% by area with a surface area of ∼20 cm \(^{2}\) . The electrodes are cleaned by a 1.2 kW, argon/oxygen microwave plasma prior to complete vircator assembly, followed by a 300 °C bake-out for 72 h. Each cathode was pulsed in a single pulse operation by an 80 J, low inductance Marx generator with an approximate pulsewidth of 100 ns full-width at half-maximum for 10 000 current pulses. The data presented includes individual gas constituents, high-speed intensified charge coupled device (ICCD) imaging, and voltage and current waveforms. The conditioning process resulted in a gas load reduction of ∼ 80% overall, with the indication that the bare bimodal fiber structure performed the best as diode power increased throughout the experiment, while the power decreased for the other tested cathode types. [ABSTRACT FROM PUBLISHER]

Carbon financing policies such as emission trading have been used to assist in emission mitigation worldwide. As energy end-users/consumers are the underlying driver of emissions, it would be difficult to effectively mitigate carbon emissions by creating an emission trading market without active end-users’ involvement. In electricity markets, demand side management (DSM) in the smart grid can manage demands in response to power supply conditions and influence end-users to contribute to improving both network efficiency and economic efficiency. However, it is a relatively new topic to study the environmental benefits of DSM. This paper proposes a two-stage scheduling model to comprehensively investigate the environmental benefits of consumers participating in both electricity and carbon emission trading markets through active DSM. A developed zero sum gains-data envelopment analysis (ZSG-DEA) model based multi-criteria allocation scheme for emission allocation is employed. Meanwhile, the carbon emission flow model (CEF) is applied to track the “virtual” carbon flow accompanying power flow. According to case studies on the IEEE 24-bus system and IEEE 118-bus system, the proposed model can effectively achieve carbon emission mitigation and provide consumers extra environmental benefits in some scenarios. This model can be an important guide for governments to establish emission trading schemes. [ABSTRACT FROM AUTHOR]

Facing increasingly serious ecological problems, sustainable development and green manufacturing have attracted much attention. Meanwhile, with the development of globalization, distributed manufacturing is becoming widespread. This paper addresses an energy-efficient scheduling of the distributed permutation flow-shop (EEDPFSP) with the criteria of minimizing both makespan and total energy consumption. Considering the distributed and multiobjective optimization complexity, a knowledge-based cooperative algorithm (KCA) is proposed to solve the EEDPFSP. First, a cooperative initialization scheme is presented with both extended energy-efficient Nawaz–Enscore–Ham heuristic and slowest allowable speed rule that are specially designed to produce good initial solutions with certain diversity. Second, several properties of the nondominated solutions are investigated based on the characteristics of the bi-objective problem, which are used to develop the knowledge-based search operators. Third, a cooperative search strategy of multiple operators is designed for the solutions with different characteristics to tradeoff two objectives. Fourth, a knowledge-based local intensification is used for exploiting better nondominated solutions sufficiently. Moreover, an energy saving method based on the critical path is used to further improve the performance. The effect of parameter setting on the KCA is investigated with the Taguchi method of design-of-experiment. Extensive computational tests and comparisons are carried out, which verify the effectiveness of the special designs of the KCA in solving the EEDPFSP. [ABSTRACT FROM AUTHOR]

Sustainability is a prevalent topic as the consumers and the governments are much more concerned about the environmental pollution. To reduce the carbon emission, in real world practice, governments have executed different forms of policies to motivate the firms to operate in a sustainable manner. This paper aims to examine the value of bargaining contract when the supply chain member invests in the sustainability projects, and explore the effectiveness of the direct (e.g., cash grant) and indirect (e.g., an increased environmental tax rate) subsidies in reducing the total carbon emission. We first derive the optimal pricing and sustainability effort under the wholesale pricing contract when either the manufacturer or the retailer makes the sustainability investment. We then consider the supply chain coordination under the two-part tariff, revenue sharing, and bargaining contracts. We uncover that only the bargaining contract can coordinate the supply chain and a Pareto improvement is achieved when the bargaining power of the manufacturer is in a specific range. Finally, we reveal that both the direct and indirect subsidies can increase the sustainability effort but they are not always an effective tool to reduce the total carbon emissions. [ABSTRACT FROM AUTHOR]

This paper discusses the modeling and analysis of a carbon capture technology-based resource scheduling/unit commitment (UC) methodology in carbon/emission-constrained environment. In carbon markets, the overall generation from conventional/fossil-fueled thermal plants is constrained over the total cost which is the sum of generation, capture cost/emission avoidance cost. Therefore, in this paper, generalized/uniform performance indices affecting the UC schedule are derived. Also, a commitment/scheduling methodology based on capture and fuel cost is devised rather than the existing penalty cost methodology as in the modernized markets everything was dealt in monetary value. Furthermore, the impact of type of resource used, i.e., coal rank is also considered to evaluate the sensitivity of scheduling decisions and financial influence of carbon capture technology. Along with performance indices, correction factors are also proposed to justify the effect of resource/coal rank in the process of optimal generation allocation. The effect of correction factors and type of coal is observed to be predominant at lower capture efficiencies compared to higher capture efficiency. The effectiveness of the proposed method over the penalty method is reflected in reduced generation cost and emission avoidance cost when compared to the penalty-based methodology. [ABSTRACT FROM AUTHOR]

This paper presents some preliminary estimates of the potential performance of a multipropellant RF plasma thruster and its format should be considered as a technical note. Interpolations of experimental results from similar devices found in the literature suggest that the first stage of such a thruster, based on well-established RF plasma torch technology, is essentially an electrothermal device. The specific impulse, in particular, is shown to be proportional to the square root of the specific power (power per unit mass flow rate). [ABSTRACT FROM AUTHOR]

Multi-energy systems can provide a constant level of service to end-use energy demands, while deriving delivered energy from a variety of primary/secondary energy sources. This fuel-switching capability can be used to reduce operating expenses, reduce environmental impacts, improve flexibility to accommodate renewable energy, and improve reliability. This paper presents four frameworks for incentivizing energy hub equipment investments for low-carbon operation targets. These frameworks vary in the measures taken to achieve low-carbon operation (explicit constraint versus carbon pricing) and in the relationship between the hub builder and operator (cooperative versus uncoordinated). The underlying energy hub model upon which these frameworks are built is an enhanced greenfield model, introducing “energy buses” to reduce dimensionality. A case study is conducted for a campus being designed in Beijing, and results from each framework are compared to illustrate their relative costs. When the operator cannot be trusted to cooperate in controlling emissions, the system must be “overbuilt” with more expensive equipment to ensure emissions target are met. A taxation-based approach increases overall costs at moderate emissions targets, but this effect decreases at aggressive targets. This paper also compares the cost of less efficient institutional frameworks with the most efficient approach, i.e., cooperation between builder and operator with constraints on emissions. [ABSTRACT FROM AUTHOR]

Rapid new product introduction is an effective method for firms to capture market share. Considering the growing concerns of environmental threats, firms are under intense pressure to measure their impacts on the environment. Before launching a new product, a firm should make the appropriate decision regarding the order quantity with incomplete information to achieve the goals of both profit maximization and environmental threat minimization simultaneously. In this paper, distribution-free news vendor models with the environmental constraints are proposed to obtain efficient order decisions. The models are formulated based on the absolute minimax regret criterion. Based on the moment bound problem framework, the models are translated into a semi-infinite linear optimization problem. In addition, the closed-form solutions of the robust order quantities and carbon emission volumes are derived. The characteristics of effective order decisions are discussed under three types of carbon emissions regulations (i.e., the carbon capacity policy, carbon tax scheme, and carbon trading mechanism). By analyzing the product characteristics from both economic and environmental aspects, four possible new product introduction strategies are proposed that the firm might employ under different environmental constraints. The characteristics of the optimal order quantity are also investigated under three carbon emissions regulations across four new product introduction strategies. [ABSTRACT FROM AUTHOR]

Managed charging of electric vehicle (EV) loads has the potential to use renewable energy more effectively, shave peak demand, and fill demand valleys while serving transportation needs. However, the potential value to the grid from managed charging has not been fully quantified. This paper adopts the tools used in the National Renewable Energy Laboratory's California Low Carbon Grid Study to quantify value to the grid from managed charging by using three levels of managed loads for 13 TW·h of annual load from three million EVs in a 2030 California grid scenario. Simulation results show that management of the EV fleet's aggregate load from unmanaged to 100% managed results in savings between $210 million and $660 million annually in generation system costs, depending on grid conditions. The simulation results also suggest that targeted EV supply equipment (EVSE) deployments at workplaces and other mid-day parking locations will be needed to support managed charging in a high-renewables California and enable the identified value to the grid. Although the value of generation to the grid from managed EV load paired with high renewables seems substantial, we estimate that the installed cost of an EVSE must be between $1000 and $3000 for a ten-year life to be cost neutral, depending on grid conditions. [ABSTRACT FROM AUTHOR]

C5-PFK has attracted much attention as one of the most promising SF 6 substitutes for medium voltage (MV) power equipment because of its high insulation strength and low global warming potential (GWP). In this paper, the dielectric properties of C5-PFK-Air and C5-PFK-CO 2 mixtures are experimentally investigated, to explore the most effective solution for C5-PFK mixtures for application in MV power equipment. The basic physical properties of C5-PFK and its mixtures are calculated and compared with those of C4-PFN based gases and SF 6 -N 2 mixtures. The GWP and saturated vapor pressure for gas mixtures are calculated, and a relative value R-GWP is defined to evaluate the greenhouse effect at specific pressure. The 50% breakdown voltages of C5-PFK-Air and C5-PFK-CO 2 mixtures under lightning impulse voltage are determined experimentally. The mixture ratio and filling pressure are determined taking into account of the ambient temperature and pressure for MV apparatus. The possibility of practical applications for these mixtures are analyzed by combining the saturated vapor pressure characteristics and the breakdown electric field strength. The synergy effects of the C5-PFK-CO 2 and SF 6 -N 2 mixtures are greater than those of the C5-PFK-Air and C4-PFN-CO 2 mixtures. The C5-PFK-Air and C5-PFK-CO 2 mixtures have higher dielectric strength than SF 6 at 0.1 MPa when the C5-PFK is about 28% under the temperature limitation of −5°C. The pressure increments of 0.014 and 0.066 MPa are required for C5-PFK-CO 2 and C5-PFK-Air mixtures, respectively to reach the dielectric strength of pure SF 6 at 0.1 MPa under the temperature limitation of − 25°C. [ABSTRACT FROM AUTHOR]

Internet data centers are booming in the last few years, leading to gigantic amount of energy consumption and greenhouse gas emission. In this paper, a data center microgrid including conventional units, energy storage, and renewable generation is modeled to optimize its electricity bill and carbon footprint. Considering the randomness of electricity price, renewable output and workload distribution, the volatility risk is incorporated to measure the associated operation risk. Then, a day-ahead emission-aware stochastic resource planning scheme is formulated to decide the strategy on power procurement, energy storage operation, batch workload allocation, and unit commitment of conventional units. Simulation results show the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

One of the critical components of high energy density pulsed power systems used to generate short high-voltage and high-power impulses is gas-filled plasma closing switch (PCS). In recent years, significant research efforts have been aimed at finding environmentally friendly gases which can be used in the PCSs, and several gases including dry air, nitrogen, carbon dioxide, argon, and their mixtures have been considered as potentially suitable working fluids in such switches. However, the lack of knowledge of the breakdown characteristics of complex switching topologies filled with these gases limits their practical applications. Therefore, further investigation of the breakdown performance of PCSs is required, in order to establish their applicability for practical use in high-voltage pulsed power systems. This paper reports on the investigation of the breakdown characteristics of a triggered PCS topology with corona discharge electrodes. The self-breakdown voltage of the switch, variation in the self-breakdown voltage, time to breakdown, and jitter have been obtained for the switch filled with “zero grade” air, N2, CO2, and an Ar/O2 mixture up to a pressure of 10 bar (abs). It was shown that the switch can provide a stable breakdown performance with jitter as low as ~1 ns. [ABSTRACT FROM AUTHOR]

This paper focus on the influence of oxygen on the partial discharge (PD) and decomposition characteristics of C 4 F 7 N/CO 2 /O 2 gas mixture as eco-friendly gas insulating medium. The PD characteristic parameters and phase resolved partial discharge (PRPD) patterns of C 4 F 7 N/CO 2 /O 2 gas mixture are, respectively, extracted and constructed. The influences of oxygen content and applied voltage on the PD and decomposition characteristics of C 4 F 7 N/CO 2 /O 2 gas mixture are investigated based on gas chromatography-mass spectrometry (GC-MS). We find that the addition of 2-4% O 2 to C 4 F 7 N/CO 2 gas mixture can significantly inhibit the negative half-cycle PDs and the generation of most by-products (CF 4 , C 2 F 6 , C 3 F 6 , CO, C 2 F 6 O 3 , CF 3 CN, C 2 F 5 CN, C 2 N 2). With the oxygen content higher than 6%, the accumulation discharge magnitude and discharge repetition rates of C 4 F 7 N/CO 2 /O 2 gas mixture increase sharply, accompanying the intensification of decomposition and deterioration of insulation strength. There is a positive correlation between the mean discharge magnitude and gas mixture decomposition intensity. To avoid the serious impact of PD fault on gas insulated equipment (GIE), the optimal oxygen addition in C 4 F 7 N/CO 2 /O 2 gas mixture should not exceed 6%. [ABSTRACT FROM AUTHOR]

Implementing renewable generation becomes one of the most practical approaches to reduce greenhouse gas emissions for the power sector. A microgrid, with its flexible scale and structure, can be a good platform to integrate distributed conventional and renewable generation resources. In this paper, a stochastic operation scheduling scheme is proposed to cooptimize carbon emissions and generation fuel costs while mitigating the impact of the intermittence of renewable energy. Two different stochastic approaches based on sample average approximation and probabilistic constrained stochastic programming are formulated. Corresponding solution methods are developed and implemented in an experimental microgrid to illustrate and compare the effectiveness of different stochastic models for the intended applications. [ABSTRACT FROM AUTHOR]

Today, Portland cement substitutes known as supplementary cementitious materials or SCMs are used to improve the performance while reducing the environmental footprint of concrete. There are several factors that impact the amount of SCMs that can be added to concrete while maintaining its basic integrity. This paper describes a newly developed framework for optimizing the substitution of cement with SCMs in concrete. This framework has been developed based on recent testing results and clearly indicates that paying close attention to cement and SCM particle size distributions (PSDs) and the corresponding packing density of the combined ingredients will allow for an optimization of the cement and SCMs in concrete. This framework has been developed on the basis of several independent laboratory studies and can be adapted as a basis for evaluating and optimizing any combination of cement and SCMs. The means to produce cement/SCM blends with the optimized PSDs with existing equipment configurations are also explored. [ABSTRACT FROM PUBLISHER]

In this paper, we analyze how carbon emissions affect the selection of transportation modes and social welfare by using a two-stage Stackelberg gaming model. Based on this model, the government’s optimal carbon-emission tax scheme and the company’s optimal transportation mode and production decisions are explored. We find that: 1) whether or not the transport carbon-emission tax can increase social welfare depends on the relationships among the social cost of carbon (SCC), the transportation mode shifting threshold (TMST), and the biggest carbon-emission tax that a company can afford (BCRA); 2) a greater SCC implies a higher probability of improving social welfare via imposing transportation carbon-emission tax; and 3) a smaller TMST or BCRA yields a higher probability of improving social welfare when a carbon-emission tax is imposed. Further study shows that imposing a carbon-emission tax on the product with a higher production cost, a bigger product volume, or a bigger product density can increase the probability of improving social welfare. [ABSTRACT FROM PUBLISHER]

Spinning reserve (SR) is one of the most important resources used by system operators to respond to unforeseen events. In a low-carbon economy mode, carbon capture plant is an important CO2 abatement option and might constitute a significant proportion of the generation mix. Due to their potential flexibility, such plants might affect the requirement for SR. This paper describes a multi-period optimization model for coordinating the generation, carbon capture and SR provision. In turn, this model is used to optimize the SR requirements, with the objective of minimizing the overall cost. Since this objective function combines the generation production cost, the expected energy not supplied (EENS) cost, SR provision cost and the carbon emission cost, it is better suited to evaluate the SR requirements of power system with carbon capture plants. Numerical results based on a 26-unit test system show that the proposed model is effective and practical. [ABSTRACT FROM PUBLISHER]

TanSat is an important satellite in the Chinese Earth Observation Program which is designed to measure global atmospheric CO2 concentrations from space. The first Chinese superhigh-resolution grating spectrometer for measuring atmospheric CO2 is aboard TanSat. This spectrometer is a suite of three grating spectrometers that make coincident measurements of reflected sunlight in the near-infrared CO2 band near 1.61 and $2.06~\mu \text{m}$ and in the molecular oxygen A-band (O2A) at $0.76~\mu \text{m}$. Their spectral resolving power ($\lambda /\Delta \lambda$) is ~19 000, ~12 800, and ~12 250 in the O2A, weak absorption band of molecular carbon dioxide band, and strong absorption of carbon dioxide band, respectively. This paper describes the laboratory radiometric calibration of the spectrometer suite, which consists of measurements of the dark current response, gain coefficients, and signal-to-noise ratio (SNR). The SNRs of each channel meet the mission requirements for the O2A and weak CO2 band but slightly miss the requirements in a few channels in the strong CO2 band. The gain coefficients of the three bands have a negligible random error component and achieve very good stability. Most of the R-squared of gain coefficients model consist of five numbers of nine (e.g., 0.99999) after the decimal point, suggesting that the instrument has significant response linearity. The radiometric calibration results meet the requirements of an absolute calibration uncertainty of less than 5%. [ABSTRACT FROM AUTHOR]

In this paper, the synergistic effect of CF3I mixed gas is theoretically analyzed using the Boltzmann method and experimentally studied under different applied voltage, pressure and electric field inhomogeneity. The experimental results show the inversion of synergetic effect, which reflects the influence of external conditions on synergetic effect. The results show that CF3I/N 2 and CF3I/CO2 mixtures under slightly uneven electric field at normal pressure have synergistic effect. CF3I/CO2 mixtures under power frequency voltage and lightning impulse have better synergistic effect than CF3I/N2. The effect of macro parameters on synergetic effect is different for different buffer gases. For CF3I/N2 mixture, the synergistic effect of the mixture can be improved by increasing the pressure and increasing the electrode gap distance. For CF3I/CO2, due to the abnormal breakdown of the mixture, negative synergistic will occur at some pressure and gap distance. [ABSTRACT FROM AUTHOR]

The vertical profile of atmospheric CO2 is of great scientific significance in identifying carbon sinks and sources, and estimating CO2 emissions or uptakes. Differential absorption Light Detection And Ranging (DIAL), has been widely accepted as the most promising technique to sense atmospheric CO2. The classical method to retrieve measurements, generated from range-resolved detection, is derived from differentiating the measured column content, but its performance in dealing with aerosol backscatter signals is poor. To address this issue, this paper proposes a derivative method, which is based on Chebyshev fitting to the measured differential absorption optical depth. We created a performance evaluation model to assess the performance of the proposed method. Simulations revealed that the error of a single CO2 profile in data retrieval can be reduced to less than 4 ppm in 6000 m. The precision of long-term mean CO2 profile is expected to be less than 1 ppm. We believe that this novel method can be used in other applications also, e.g., trace gas measurements collected using DIAL, especially when the signal-to-noise-ratio of received signal is small. [ABSTRACT FROM PUBLISHER]

In order to achieve sustainable development goals, modern power systems need to achieve a low-carbon transition. Retirement and replacement of aging coal-fired power plants (CFPP) is the major part of electricity network transition. However, the sudden retirement of large aging CFPP could lead to power supply or reserve shortages and generally, it takes several years to complete the replacement process. This paper proposes a low-carbon electricity network transition model, helping to plan aging CFPP retirement and renewable power plants installation as well as network augmentation. The trade-off decisions are found among three conflicting objectives including cost, risk and carbon emission. Moreover, the carbon emission flow (CEF) model is applied in the planning process to calculate carbon emissions from the demand side, in order to assess the efficacy of the low-carbon transition. A relatively new multi-objective natural aggregation algorithm (MONAA) is introduced and applied to find the optimal solution. The proposed model is verified on a modified IEEE 24-bus RTS system and a modified IEEE 118-bus system. According to the numerical results, the proposed model can achieve carbon mitigation, cost and risk benefits and provide a roadmap to guide the energy network transformation towards a low-carbon economy. [ABSTRACT FROM AUTHOR]

Air-pollutant and greenhouse gas emissions typically have high gas flow rates and low concentrations (in ppm ∼ % levels, 1% = 10 000 ppm). The bulky equipment required for direct treatment of high-flow-rate low-concentration exhaust gases result in high-energy consumption and prohibitive operating costs. As such, the objective of this study is to convert high-flow-rate low-concentration exhaust gases into low-flow-rate high-concentration gases. This is achieved by desorbing the gas from an adsorbent by applying an atmospheric plasma inside a nonthermal plasma (NTP) reactor. This paper focuses on carbon dioxide (CO2) concentration (condensation) via this method. The adsorbent consists of spherical ∼2-mm-diameter molecular-sieve pellets of zeolite. Plasma desorption is performed by applying nanosecond high-voltage pulses (peak voltage ∼35 kV, pulse frequency = 140–350 Hz, and pulse width ∼600 ns) to the plasma reactor. A gas flow rate of 4 L/min is used and the concentrations of CO2, O2, H2O, and N2 gases are 2.75%, 18%, 1%, and the balance, respectively. The results reveal that CO2 can be desorbed effectively and more rapidly in a repeated adsorption and NTP desorption process than during the thermal process. Moreover, for the same electric power, the peak concentrations (typically 13%) are higher in the NTP desorption process than in the thermal process at equal electric power. These results indicate that the efficient NTP dissociation of CO2 to CO, which can be utilized in the production of combustion fuels, is possible. [ABSTRACT FROM AUTHOR]

This paper reports on the dependence of voltage rise rate on positive streamer branching and shock waves in supercritical carbon dioxide. Voltages with rise rates of 0.21 and 4.5 kV/ns were applied to a needle-to-plane electrode. Prebreakdown phenomena involving streamer growth and shock wave propagation were observed by means of a shadowgraph method. The results show that the spread angle of the streamer at the needle tip under 4.5 kV/ns was nearly twice as large as that under 0.21 kV/ns. The discharge may initiate without density reduction due to electrostrictive force. While shock wave Mach number was little affected by the voltage rise rate, it increased by increasing the negative voltage peak. Consequently, the velocity of shock wave is presumed to be influenced by the population of the vibrational state of carbon dioxide. [ABSTRACT FROM PUBLISHER]

Energy and conversion efficiencies of the carbon dioxide (CO2) dissociation process at atmospheric-pressure conditions are investigated using a direct-coupled continuous microwave plasma system (MPS). Gas chromatography and mass spectrometer measurements were performed on the gas mixture postplasma treatment, over a range of specific energy inputs (SEIs) (0.06–0.6 eV mol ^-1) , in order to determine species mass fractions of CO2, carbon monoxide, and oxygen. In this region of SEI, energy efficiency is maximized at the cost of conversion efficiency. The corresponding maximum observed quantities for conversion efficiency and energy conversion efficiency (ECE) occurred at conditions close to the end of the test range and are, respectively, 9% and 0.0048 L min ^-1\textW^-1 . The maximum throughput of CO2 converted was 0.59 L min ^-1 , at an SEI of 0.1 eV mol ^-1 and an ECE of 0.004 L min ^-1\textW^-1 . Optical emission spectroscopy was used to approximate the rotational and vibrational temperatures of the plasma system to be in the range of 7000–8000 K. This paper suggests that an MPS is the most energy efficient method in dissociating CO2 under atmospheric pressure and, therefore, most suitable to be used in a CO2 recycling setup, which can further increase conversion rates. [ABSTRACT FROM PUBLISHER]

SF6 is widely used in C-GIS as an insulating medium. However, SF6 and its decomposition products can pollute environment and harm human health and equipment. Firstly, this paper verifies the high-energy discharge promotes CF3I to produce C2F6 and I2 by simulation. Therefore the paper puts forward the significance of using mixture gas to reduce the use of CF3I and control the produce of I2. Secondly, the partial discharge inception voltages in the positive half cycle of power frequency (PDIV+) of CF3I/CO2 under different pressures, mixing ratios (k) and interelectrode distances were measured and compared with SF6/CO2. The results show that: when k is more than 10%, the PDIV+ of CF3I/CO2 is close to or higher than SF6/CO2 in the same experimental conditions; The PDIV+ of CF3I/CO2 (30%-40%) at 0.15-0.2MPa can reach the level of pure SF6 in 0.1MPa. The breakdown experiments under different electric fields shows that the breakdown characteristic of CF3I/CO2 (30%-40%) at 0.15-0.2MPa can exceed the level of pure SF6 at 0.1MPa. Considering the boiling point, producing of I2 and insulating property, CF3I/CO2 (30%-40%) is likely to replace SF6 used in C-GIS. [ABSTRACT FROM AUTHOR]

There has been growing interests in recent years for the safe underground storage of carbon dioxide (CO2) as a potential technology for preventing this greenhouse gas from entering the atmosphere. As suitable locations for geological storage may be diverse, the applicability of various geodetic and geophysical methods for surveillance and monitoring purposes must be investigated. In this paper, we evaluate the ground surface displacement at the Ketzin pilot site for CO2 storage in Germany, using satellite-based measurements and hydromechanical simulations. The InSAR observations, using more than four years of TerraSAR-X data from 2009 to 2013, reflect the stability of the Ketzin pilot site (long-term velocity <0.5 mm/year) in conjunction with the accumulated CO2 volume in the reservoir. This can be due to the low overall pressure change, with a maximum of 16 bar, which is not causing significant surface displacement. However, such overall stability can be interrupted temporarily, as detected within the InSAR time series for a distinct period of noninjection from May to December 2012 (subsidence of 2.8 mm). This is supported by our hydromechanical simulation results, exhibiting a maximum ground surface subsidence of approximately 1 mm during this period, and by a comparison with variations in bottomhole pressure, indicating a positive correlation of 80%. [ABSTRACT FROM AUTHOR]

Differential absorption lidar (DIAL) is widely accepted as the most promising remote sensing means to map the global CO2 concentrations. Nevertheless, diurnal variations and vertical distributions of atmospheric CO2 cannot be obtained by satellite-borne and airborne measurements. Ground-based DIAL systems are developed to fill this gap, as well as serve as validations for satellite-borne measurements. Atmospheric factors play significant roles in obtaining accurate range-resolved measurements of XCO2. However, the influence of atmospheric factors on the performance of a ground-based DIAL system aiming at CO2 measurements has not been dedicatedly discussed yet. The pressure, temperature, and water vapor of the atmosphere have been taken into consideration for performance evaluation after preselection of absorption lines around 1.6 μm in this paper. In addition, errors caused by variations of aerosols have also been analyzed by using theoretical simulations and real measurements. We found that biases caused by temperature and pressure uncertainties were 0.11-0.45 ppm/K and 0.39 ppm/hPa, respectively, if the central wavelength was utilized as the online wavelength. In addition, the water vapor effect could be neglected by cautious selection of online and offline wavelength. Finally, if the online and offline wavelengths were transmitted alternatively, the temporal and range resolutions have to be determined very carefully to balance the signal-to-noise ratio of acquired data and tolerable errors derived from variations of aerosols. A variable range resolution is recommended for CO2 measurements at different altitudes to fulfill the target precision. [ABSTRACT FROM AUTHOR]

In this paper, an averaging pitot tube (APT) with flow conditioning wing (FCW) geometry is used as a practical sensing device to measure and characterize the flow of single-phase gaseous carbon dioxide (CO2). This technique demonstrates a simple, cost-effective, and potentially accurate option toward the measurement, accurate accounting, and characterization of CO2 in carbon capture and storage pipelines. The metrological performance of the flow sensor is verified using air medium before being applied for gaseous CO2. With a Coriolis mass flowmeter acting as a secondary calibration reference to further validate the performance of the APT-FCW flow sensor, both metering instruments were evaluated against a weighing scale apparatus. From the experimental and calibration data with air, the APT-FCWs average $K$ -factor and linearity error are found to be 0.5091 and 0.725%, respectively. With operating conditions remaining unaltered in this particular flow measurement application and a target metering error within ±1%, the errors achieved for the Coriolis meter and the APT-FCW are better than ±0.6% and ±1.2%, respectively. Total uncertainty estimations under the stipulated environmental and working conditions are within ±1% and ±1.5% for the Coriolis meter and APT-FCW, respectively. The test results and other performance evaluation of the instruments are also discussed. [ABSTRACT FROM PUBLISHER]

This paper reports on the study of repetitive nanosecond-pulsed discharge splitting of carbon dioxide (CO2) for the production of CO. Gas chromatography is used to analyze the composition of the reformed gas when CO2 is exposed to high-voltage (15 kV) very short (10 ns) electrical discharges that deposit as much as 0.4 mJ of energy at a rate of 30 kHz. Conversion rate and energy efficiency are obtained while the discharge pressure is varied between 2.4 and 5.1 atm. At the tested conditions, the maximum conversion rate and energy efficiency are found to be 7.3% and 11.5%, respectively. The energy efficiency drops slightly with increased pressure because of the decreased electric field and electron energy per molecule. An energy balance analysis of a set of CO2 plasma reactions reveals that the dominant dissociation pathway under these conditions passes through the excitation of CO2 (10.5 eV) followed by autodissociation into CO and O, which are often in excited states. [ABSTRACT FROM PUBLISHER]

As a clean fuel source, natural gas plays an important role in achieving a low-carbon economy in the power industry. Owing to the uncertainties introduced by increasing utilization of natural gas in electric power system, gas system and electricity system should be planned in an integrated manner. When considering these two systems simultaneously, there are many emerging difficulties, e.g., increased system complexity and risk, market timeline mismatch, overall system reliability evaluation, etc. In this paper, a novel expansion co-planning (ECP) framework is proposed to address the above challenges. In our approach, the planning process is modeled as a mixed integer nonlinear optimization problem. The best augmentation option is a plan with the highest cost/benefit ratio. Benefits of expansion planning considered are reductions in operation cost, carbon emission cost, and unreliability cost. By identifying several scenarios based on statistical analysis and expert knowledge, decision analysis is used to tackle market uncertainties. The operational and economic interdependency of both systems are well analyzed. Case studies on a three-bus gas and two-bus power system, plus the Victorian integrated gas and electricity system in Australia are presented to validate the performance of the proposed framework. [ABSTRACT FROM PUBLISHER]

The most dangerous effects of anthropogenic climate change can be mitigated by using emissions taxes or other regulatory interventions to reduce greenhouse gas (GHG) emissions. This paper takes a regulatory viewpoint and describes the Weighted Sum Bisection method to determine the lowest emission tax rate that can reduce the anticipated emissions of the power sector below a prescribed, regulatorily-defined target. This bilevel method accounts for a variety of operating conditions via stochastic programming and remains computationally tractable for realistically large planning test systems, even when binary commitment decisions and multiperiod constraints on conventional generators are considered. Case studies on a modified ISO New England test system demonstrate that this method reliably finds the minimum tax rate that meets emissions targets. In addition, it investigates the relationship between system investments and the tax-setting process. Introducing GHG emissions taxes increases the value proposition for investment in new cleaner generation, transmission, and energy efficiency; conversely, investing in these technologies reduces the tax rate required to reach a given emissions target. [ABSTRACT FROM AUTHOR]

This paper presents a bifuel hydrogen–gasoline internal combustion engine (ICE) as an effective strategy for extending the electric vehicle's ranges. The electric power produced by the proposed ICE linked with a generator is a nonlinear function of the engine speed and the proportions of hydrogen and gasoline mixed fuel can be approximated around operating conditions. This nonlinear function is approximated by the Taylor series and a comparative study between the obtained results and the experimental data showed the effectiveness of the proposed approach. Furthermore, we observed that the Taylor series approach can achieve less than 7% error, while the modeling with an artificial neural network or a recursive least square method results in more than 8% error. To enable the ICE operation with maximum efficiency, a nonlinear optimization method is used. The proposed maximum efficiency tracking approach is compared with that of the most used industrial methods based on constant speed. The results show that the proposed approach can result in more than 7% of saving in energy, compared to that of the industrial method. [ABSTRACT FROM AUTHOR]