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In this study, an integrated energy system is deployed to generate electricity, heating, cooling, and domestic hot water for a community considering three fully renewable energy source scenarios: biofuel (Case I), solar-biofuel (Case II), and geothermal energy (Case III). The proposed systems are modeled, assessed, optimized, and compared thermodynamically, economically, and environmentally; in addition, a proton exchange membrane electrolyzer (PEME) is utilized to convert the surplus electricity to stored hydrogen to raise the exergy efficiency and package value-added. Mathematical models are fully developed from thermodynamic and economic perspectives, taking a cumulative inflation rate into account via the Consumer Price Index (CPI). The novelty of the study is to focus on the comparison of the proposed renewable resources as energy inputs for the same condition (community loads), as there is a gap in this regard in the literature. Presented systems are optimized using Non-dominated Sorting Genetic Algorithm-II (NSGA-II) for minimum net costs as well as maximum exergy efficiency to reach the optimum operating conditions for each case during the peak cooling and heating loads. Moreover, for a more precise comparison of the proposed cases from an exergetic, economic, and environmental point of view, dynamic (hourly) behaviors of systems are analyzed over a year. A comprehensive parametric study is carried out to reckon the influence of borehole drilling depth, geofluid mass flow rate, and soil temperature gradient on case III to appraise its competitiveness in different locations, as well as the effects of the number of collectors on total cost rate and exergy efficiency for case II. Results indicate the annual net costs of $107.1k, $99.5k, and -$505.1k (where the negative sign stands for "income" instead of "cost") and average exergy efficiencies of 19.1 %, 26.3 %, and 41.3 % for cases I, II and III respectively. [ABSTRACT FROM AUTHOR]

Diesel generators used for off-grid power generation and other applications waste a significant amount of input power as heat (about 65%), contributing to global warming. To mitigate this, waste heat recovery and utilization systems can be employed. The current study, focuses on utilizing waste heat from a 2.5 MW diesel generator for freshwater production through integrated humidification dehumidification (HDH) systems. Four different HDH system layouts are investigated, considering factors such as dehumidifier and humidifier effectiveness, temperature differentials, mass flowrate ratio, and ambient temperature. The aim is to analyze and optimize the system's pure water productivity, recovery ratio, specific entropy generation, and gained output ratio. The results show that the layout featuring an air heated – air heated cycle (AH-AH) performs the best, with the highest productivity and gained output ratio of 234.48 m3/day and 3.01, respectively. On the other hand, the water heated – water heated cycle (WH-WH) layout exhibits lower performance. The study demonstrates the potential to recover 46–70% of the waste heat, significantly improving the diesel engine's utilization factor from 36% to 68%. The proposed system also proves cost-effective, with freshwater production costing as low as 0.62 $/m3 when utilizing waste heat, compared to 4.11 $/m3 and 13.96 $/m3 when using steam or electric heating elements. Furthermore, the integrated system helps reduce the environmental impact by minimizing waste heat discharge into the environment and thus contributes to mitigating global warming. • Waste energy between 46% and 50% from a diesel Engine can be recovered by desalination systems to produce freshwater. • The energy efficiency (utilization factor) of the Diesel Engine improved from 36% to 68%. • A maximum freshwater productivity of 85,585 m3/per annum can be achieved by the desalination systems. • Freshwater price as low as 0.62 $ per cubic meter can be attained from proposed integration. [ABSTRACT FROM AUTHOR]

The increasing penetration of photovoltaic technology in the electricity market requires the development of a methodology that facilitates the optimisation of photovoltaic plants with single-axis trackers. This paper presents an optimisation methodology that takes into account the most important design variables of single-axis photovoltaic plants, including irregular land shape, size and configuration of the mounting system, row spacing, and operating periods (for backtracking mode, limited range of motion, and normal tracking mode). Equations for the determination of the optimal row spacing and operating periods have been developed and is presented in detail. A packing algorithm that takes into account the irregular land shape and the possible configurations of the mounting systems is also presented. The objective function is the total area of the photovoltaic field and the optimisation is performed by a packing algorithm. As the economic aspect of energy generation also plays a key role in decision-making, the levelised cost of energy has been used to assess the economic viability of the optimal layout of the mounting systems. The results show that the proposed methodology and packing algorithm are able to optimise the photovoltaic plant with single-axis solar tracking and provide reliable results after a reasonable computation time. The methodology was demonstrated in detail for a Spanish photovoltaic plant (Granjera photovoltaic power plant), including the optimal layout of the mounting systems and the cost analysis for this layout. The optimal layout of the mounting systems could increase the amount of energy captured by 91.18% in relation to the current of Granjera photovoltaic power plant. The mounting system configuration used in the optimal layout is the one with the best levelised cost of energy efficiency, 1.09. The presented optimisation methodology can be utilised to facilitate the optimal design of commercial photovoltaic plants with single-axis trackers. Therefore, questions such as: what is the optimal distribution of mounting systems?, how much energy will this distribution produce?, and at what cost will it produce it?, can be answered by using the proposed methodology. • The optimal layout of single-axis solar trackers in large-scale PV plants. • A detailed analysis of the design of the inter-row spacing and operating periods. • The optimal layout of the mounting systems increases the amount of energy by 91%. • Also has the best levelised cost of energy efficiency, 1.09. [ABSTRACT FROM AUTHOR]

The low freshwater production of the solar distillers is one of the most crucial obstacles to their effective use in distillation applications. In this work, an attempt has been made to ameliorate the distilled yield of the hemispherical solar distiller. This was fulfilled by using a v-corrugated basin and reversed solar collector in order to augment the evaporation area and assist in reflecting more solar irradiance onto the outer surface of the v-corrugated basin. Two hemispherical solar distillers, namely; v-corrugated basin hemispherical distiller integrated with a reversed solar collector (VBHD-RSC) and traditional flat basin hemispherical distiller (TFBHD) were designed and examined at the same outdoors conditions of El-Oued (33°27′N, 7°11′E), Algeria. Moreover, a comparative energic-economic analysis of the two proposed hemispherical distillers has been conducted in terms of freshwater productivity, daily energy efficiency, and freshwater distillate cost. The results show that the daily accumulative yield of the VBHD-RSC was 7.85 kg/m2.day which was higher than that of TFBHD by 68.82%. Moreover, the daily energy efficiency was obtained to be 59.70% and 35.52% for VBHD-RSC and TFBHD, respectively. Furthermore, the economic assessment indicates that the usage of a v-corrugated basin embedded with a reversed solar collector was more cost-efficient as it reduces the cost of freshwater production by 27.12% compared to TFBHD. [ABSTRACT FROM AUTHOR]

Carbon emissions in mobility, as one of the primary causes of global warming, are regulated by various organizations with different legislations. Different energy sources and power-train solutions are used to comply with these constraints. Hydrogen-fueled, fully electric, and hybrid vehicles are at the forefront of these technologies. Within the scope of this study, gasoline-, diesel-, and hydrogen-fueled internal combustion engines, and fully electric and serial hybrid 18-m city bus vehicles were modeled. Comprehensive analyses of emissions and costs, considering both the entire energy production and consumption cycles for various vehicle types were conducted. Models that are primarily based on fuel consumption data show that while fully electric vehicles currently have the lowest emissions, hydrogen-fueled vehicles can play a more prominent role soon with the increasing production of green hydrogen. For the first step of hydrogen implementation in the industry, H2ICE is a promising for both reduced carbon emissions in mobility and cost-effectiveness. If the forecasted hydrogen production and distribution scenario is adopted by industrial and energy organizations, it is evident that by the year 2030, more environmentally friendly operation can be achieved particularly in the context of public transportation. Embracing this approach is likely to lead to positive environmental sustainability impacts in future transportation systems. • Well-to-wheel emission and cost analyses for 18-m city buses with different powertrain types were performed by considering the production rates and transportation via various methods of the related fuels (gasoline, diesel, hydrogen, and electricity). • The findings reveal that, in the present context, fully electric vehicles emerge as the most favorable choice, excelling not only in emissions reduction but also in cost efficiency. • The optimistic scenario for 2030 proposed by this study is examined, hydrogen fuel emerged as a promising candidate for the future of urban bus transportation, demonstrating both the lowest emissions and cost. [ABSTRACT FROM AUTHOR]

Existing lifecycle assessment models narrowly concentrate on limited parameters, disregarding system ecology and multi-stage stakeholder integration with sequestered analyses. Assimilation of new transport technologies with traditional design-bid-build decision-making paradigm should acknowledge sustainability triple-bottom-line social, cost, and environmental impacts, across all lifecycle stages for a system-wide optimisation. This study presents a multilevel framework to evaluate road transport system projects utilising 1) stakeholder engagement for flexibility in establishing key performance indicators, 2) passenger surveys to identify what encourages mode choice towards public transport, 3) microsimulation models , lifecycle cost and lifecycle analysis for quantitative assessment, 4) analytic hierarchy for qualitative assessment, and finally 5) multi-criteria modelling with stakeholder expert group preferences. Framework is applied to a 5-lane dual carriageway project in Abu Dhabi, analysing eight virgin and recycled material-based and public transport service alternatives. Study revealed the significance of saved user time, reduced fuel consumption during use phase and vehicle operational costs as the highest lifecycle impact generators. The total sustainability performance across the lifecycle for all alternatives was affected by traffic gridlock formation due to traffic growth in later years and lack of traffic load reduction strategies. Results showed that an autonomous vehicle-based bus rapid transit service coupled with recycled material to construct the road significantly reduced lifecycle cost (51.1%), energy (55.6%) and pollutant (54.5%-CO 2 , 49.7%-NO x , 24.1%-PM) burdens. It exhibited effectiveness of system choice using lifecycle assessment over the typically fragmented project planning and evaluation approach. Overall, framework exhibited robustness against unit cost and LCI uncertainties, fuel distribution assumptions, discount rate, and indicator weights variations based on priorities of different stakeholder groups. • A framework is developed, integrating indicators for sustainability triple-bottom-line impacts. • The MCDM unifies both quantitative (from empirical models) and qualitative (stakeholder) data. • Highway case study data from Abu Dhabi is used to test the MCDM framework for 2015–2045 service life. • Two roadworks scenarios: traditional approach versus recycled materials, used actual field data. • Traffic scenarios: BAU, public bus, BRT and autonomous-BRT used high-resolution traffic models. • Results showed that autonomous BRT coupled with recycled materials significantly reduced life-cycle impacts. [ABSTRACT FROM AUTHOR]

• Successful recovery of both nitrogen and phosphorus from real digester centrate is realized. • Addition of cation exchange membrane helps maintain pH in different chambers. • By-product of electrolysis - acid can be used for ammonia recovery. • Energy consumption and cost for nitrogen recovery can be potentially competitive. Recovering nutrients from wastewater will not only address pollution issues, but also reduce the need for nutrient from energy/resource - intensive production. Herein, a four-chamber electrochemical membrane system (4C-EMS) was developed to recover both nitrogen and phosphorus from real digester centrate through synergistically coupling electrodialysis with membrane contactor. The 4C-EMS successfully recovered more than 95 % of nitrogen and 85 % of phosphorus. The lowest specific energy consumption of 8.2 ± 0.2 kWh kg−1 N was achieved under 1.25 mA cm−2. A byproduct of the electrolysis – acid could compensate for 10∼32 % of total acid needed for ammonia absorption. The 4C-EMS effectively reduced heavy metals in struvite by 98 % compared to the struvite formed directly from the digester centrate. A preliminary cost analysis examined the relationship between acid price and dosage and estimated the operating cost of $0.58∼0.83 kg−1 N; simultaneously recovered phosphorus would further increase the benefit of this system. [Display omitted] [ABSTRACT FROM AUTHOR]

China has been placing a substantial focus on biogas for reducing energy consumption and carbon dioxide (CO 2) emissions. The operation mode of biogas systems may make the CO 2 reduction target over-optimistic. There is limited research to investigate the influential factors that may be causing the gap between the actual and theoretical CO 2 reduction costs of biogas systems in China. In this research, by using field survey data of 209 biogas users and 489 non-biogas users from 19 villages in 2015, the gap between actual and theoretical unit CO 2 reduction cost is quantified at approximately 156 USD/t CO 2. By employing the Logarithmic Mean Divisia Index I (LMDI) model, it is found that both the cost effect (48%) and the reduction effect (52%) contribute to the unit CO 2 reduction cost gap. Four influential factors–household labor, accessibility to the energy resource, acceptance of biogas technology, and subsidy–significantly narrow the gap between actual and theoretical CO 2 reduction costs, while the levelized subsidy contributes to widening the gap. On average, biogas systems should be operated for at least four years and the substitution rate should be more than 67% in order to keep the gap between actual and theoretical CO 2 reduction costs under 50%. • Actual and theoretical CO 2 reduction costs of biogas systems are assessed. • The gaps are decomposed to the cost effect and the reduction effect. • Five key influential factors are investigated to narrow the gap. • The under-estimated CO 2 reduction costs of biogas systems are evaluated. [ABSTRACT FROM AUTHOR]

The novel methanol production from carbon dioxide (CO 2) and hydrogen (H 2) called alcohol-assisted process is simulated. Although the alcohol-assisted process allows the reduction in operating temperature and pressure, the subsequent product purification is complicated. Comparative studies between the conventional CO 2 hydrogenation and the alcohol-assisted processes are carried out (case I–V). The alcohol-assisted processes present the opportunity of increasing the CO 2 conversion per-pass and reducing 25% of the hydrogen consumption, the barriers in the conventional process. However, the product purifications remain challenging due to the azeotrope of methanol and by-products. Energy consumptions decrease in the feed and reaction sections of the alcohol-assisted processes but significant increase in the product purifications. The formation of by-products and the sequence of purification units affect process performance and economics. The obtained results indicate that the product purification and the catalyst development to increase methanol selectivity and produce an easy-separated by-product play key roles in the enhancement of the process feasibility. • Novel methanol production from CO 2 and H 2 called alcohol-assisted process is simulated. • The new process increases CO 2 conversion per-pass and reduces H 2 consumption. • Product purification and catalyst development play key role in the process feasibility. [ABSTRACT FROM AUTHOR]

HFCs that were accepted globally in refrigeration and air conditioning applications may soon be phased out due to environmental concerns. The primary driver behind the phase-out of HFCs is their elevated global warming potential (GWP). As a result, the demand for suitable, environmentally friendly substitutes has been increased. Hydrofluoroolefins (HFOs) are a novel family of environmentally benign refrigerants that have gained popularity in recent years. Moreover, despite their significant flammability, hydrocarbons (HCs) can also serve as viable substitutes for halogenated refrigerants due to their positive environmental impact, energy efficiency, coefficient of performance (COP), refrigerant mass, and compressor discharge temperatures. As possible retrofits for conventional refrigerants, the current review aims to address several pure HCs, HFOs, and HFCs as well as their mixtures. It also addresses their flammability characteristics, such as minimum inerting concentration, critical suppression ratio, inert effect, and flammability, as well as their performance parameters, such as coefficient of performance, compressor power consumption, pulldown time, optimal refrigerant charge, and exergy destruction. Various methods for determining the MIC of the refrigerant mixtures are reported. Cost analysis of different refrigerants and refrigeration with Nano-refrigerants were also discussed. Moreover, this study conducted a comprehensive examination of prior research which helps in identifying the eco-friendly refrigerants for domestic applications. [Display omitted] • Comprehensively reviewed the flammable limits of hydrocarbon, hydrofluorocarbon, and hydrofluoroolefins and their mixtures. • Inert effect of different dilutants such as R134a, R13I1, R125, R227ea and R245fa with hydrocarbon, hydrofluorocarbon, and hydrofluoroolefins are discussed. • Summarized the various methods to determine the minimum inerting concentration of different refrigerant mixtures. • The performance studies of various eco-friendly refrigerants used in domestic applications have been reviewed. • Refrigerant compositions that are non-flammable and possess Low GWP, ODP are identified for domestic applications. [ABSTRACT FROM AUTHOR]

The depletion of unsustainable conventional energy sources and global warming issues create world demand for green energy sources. The microbial fuel cell (MFC) technology with the capability to convert environmental waste to energy can be improved with cheap ceramic material. The ceramic is structurally porous, thus allow a direct exchange of cation. The ceramic material also enhances stability thermally and chemically, non-ion selective characteristic, high mechanical strength, and easily washable. Commercially produced ceramic structures have been proven to reduce Chemical Oxygen Demand up to 92% and allow high power output. It is also comparatively durable in the long-term operation of MFC, compared to the commercially available membrane. The novelty of using tubular design is the efficient use of space, which leads to the possibility of scaling up. As a conclusion, a combination of both ceramic material and tubular design could be an excellent alternative separator for MFC. • Performance of ceramic membrane is on par or better than conventional membrane. • Ceramic membrane is 'hardy' against fouling and chemical scaling. • Cost per energy produced using ceramic membrane is more profitable than conventional membrane. • Tubular ceramic membrane is the most reported type of design. • Previous studies use multiple tubular design instead of single big volume cell. [ABSTRACT FROM AUTHOR]

Poultry housing is chosen for the development because it has the highest portion of energy consumption. Solar energy and climate control systems are utilized for producing the highest productivity and conversion rate poultry housing comparing with the conventional methods. Thermal analysis of solar heating unit and photovoltaic is conducted to find out their thermal efficiencies. Experiments are conducted under the following conditions using three power operating systems [flat-plate solar collector + electricity (power operating), flat plate solar collector + photovoltaic and conventional system (depending on only electricity)] and fan stopping periods (2, 5 and 8 min). The poultry house performance was evaluated in terms of relative humidity, ammonia concentration, poultry production, feed conversion rate, required power and production cost. Based on the theoretical analysis, the efficiency of the solar heating system and photovoltaic cells was about 71.6% and 12.5%, respectively. Experimental results reveal that the optimum conditions for enhancing the poultry production (2.29 kg) with conversion rate (1.45 kg feed per kg gain), ammonia concentration at the fifth week (13.65 ppm), production cost (1.12 US $/kg) are achieved by using power operating system of flat-plate solar collector integrated with photovoltaic under 2 min fan stopping periods. • Develop poultry house to be operated by solar energy and climate control systems. • Compare the poultry house performance using two solar power operating systems (flat-plate solar collector and photovoltaic). • Study the effect of fan stopping periods on ammonia gas emission. • Evaluate the effect of using solar energy and climate control systems on poultry house performance economically. [ABSTRACT FROM AUTHOR]

This study reviewed the recent updates on the pretreatment methods employed towards the enhancement of hydrogen production. Low hydrogen yield was considered to be a current obstacle for hydrogen utility on the industrial scale. On pretreating, the wastewater, the structure of the macromolecule gets dissipated and destroyed which reduces the polymerization potency. It favors the availability of monomers for the fermentation process. Various pretreatment methods with operating conditions and parameters were documented along with their pros and cons. Mainly, the pretreatment methods adopted for reducing the toxicity levels of wastewater to enhance biohydrogen production are dealt with in detail. Pretreatment methods have shown a positive impact on most of the cases studied. It acts on various components of wastewater and makes it amenable for the hydrogen-producing microbiome. Energy balance methodologies have also been provided towards the selection of a cost-effective and sustainable approach. Perspectives and recommendations on pretreatment systems were directed towards the development of a successful hydrogen economy. Overall documentation details the significance of pretreatment in the fermentation process for higher hydrogen yield. • Hydrogen generation was a holistic approach to reduce environmental pollution. • Hydrogen generation was accelerated by pretreatment process. • Pretreatment process accelerates the hydrogen generation capacity of wastewater. • Selection of appropriate pretreatment enhances sustainable hydrogen generation. • Commercialization of pretreatment for hydrogen intensification remains provocative. [ABSTRACT FROM AUTHOR]

A bench-scale apparatus was used for the low-temperature thermal desorption (LTTD) treatment of oil-based drill cuttings (OBDCs). The effects of treatment temperature, treatment duration, sand/OBDCs mixing ratio, and initial oil content on the LTTD treatment performance were investigated. It was found that the petroleum hydrocarbons (PHCs) were barely left in the high-oil-content drill cuttings after LTTD (at 300 °C for 20 min), and thus the overall soil health was improved. The desorption kinetics models of PHCs under various conditions were established, and it was found that the LTTD of OBDCs followed nonlinear least-squares exponential kinetics (adjusted R2 > 0.9). The energy consumption models of LTTD treatment under different temperatures were also developed. The modeling results are of practical guiding significance and useful for designing effective LTTD treatment systems of OBDCs. • Low-temperature thermal desorption (LTTD) was examined to treat drill cuttings. • Kinetics models were developed to study petroleum hydrocarbons (PHCs) desorption. • Energy consumption models of LTTD were established for treatment cost analysis. • Addition of sand to drill cuttings could increase the desorption rate of LTTD. • LTTD enhanced soil health by removing PHCs and increasing phosphorus contents. [ABSTRACT FROM AUTHOR]

The need to reduce energy consumption in seawater Reverse Osmosis (RO) process has pushed research towards the development of new hybrid systems in which, for example, other membrane processes can be used to pre-treat seawater. Electrodialysis (ED) and Reverse Electrodialysis (RED) can act as a pre-desalting step before seawater enters the RO unit, thus leading to an important energy saving in RO. In this work, two coupled models are proposed for the RED-RO and ED-RO systems. Each process model was validated. Then a sensitivity analysis was performed to assess the effect of the integration on the overall process cost saving. The analysis was performed by changing ED or RED voltage and RO pressure and considering eight different cost scenarios. The performance of the hybrid system was compared with the stand-alone seawater RO process. Competitive scenarios were found especially for the RED-RO case, by optimizing the pre-desalting extent, with significant cost saving and promising potentials for future industrial implementation. Unlabelled Image • A validated simulation tool for hybrid membrane desalination systems is presented. • The (A)RED-RO coupling provides energy and cost savings compared to SWRO. • The ED-RO coupling turns out to be non-competitive in the investigated range. • Different costs scenarios highlight the conditions for system competitiveness. • Perspective scenarios using high performing IEMs provide significant cost savings. [ABSTRACT FROM AUTHOR]

Deep energy retrofits of existing buildings can contribute to achieving a renewable-based society, though they are mostly lacking in the EU. To understand the cost and primary energy savings of deep energy retrofits, all life cycle phases, including construction, operation, maintenance and end-of-life, must be considered. The initial building without retrofit must be analysed over its remaining lifetime covering energy operation, maintenance and end-of-life implications that change with a retrofit. Such a method is applied to a multifamily building retrofitted to two passive house standards limiting annual final heat use to 50 and 30 kWh/m2. Energy improvements to the building envelope are analysed considering different versions of initial cladding materials and retrofit materials, and different economic and electricity supply scenarios. A retrofit to 50 kWh/m2 is profitable for all economic scenarios while the 30 kWh/m2 version is profitable for most of the scenarios giving net primary energy savings of 57–60% and 63–72%, respectively, compared to the non-retrofitted building. The cost of different retrofit materials is similar, while the primary energy use is much lower for wood-based materials. The changed costs and primary energy use for the non-retrofit building, in maintenance and end-of-life phases, varies depending on assumed initial cladding materials. • Energy renovation of buildings is key to mitigating climate change. • Lifecycle cost and primary energy of different passive house standards are studied. • Deep retrofit to 30 kW h/m2 is close to be cost efficient for higher biomass prices. • Different material versions have similar costs but quite varied primary energy use. • Different electricity production scenarios affect primary energy, marginally costs. [ABSTRACT FROM AUTHOR]

This study investigates the performance of a Carnot Battery and performs a thermodynamic-based sustainability analysis using different methods. Carnot batteries have two different operational processes, charge and discharge. Electricity generated from a renewable source is used to operate a heat pump and the heat rejected by the heat pump is stored in the battery, which is then used to generate electricity in the Organic Rankine Cycle (ORC) at night and called as the discharge process. Climatic data from the city of Izmir, the third largest city by population in Turkey, has been chosen for the dynamic analysis. Exergy-based sustainability and thermo-ecological cost analyses are performed. The results show that the maximum Coefficient of Performance (COP) of the heat pump system is 4.5, the exergy efficiency can reach 0.78 and its the maximum sustainability index is 4.5. For the discharge process, energy efficiency of the ORC is 0.118 while the exergy efficiency is around 0.49 with a sustainability value of about 2.0. [Display omitted] • A novel analysis method for PV driven batteries is presented • Method combines exergy-based and thermo-ecological concepts • Exergy efficiency for charge and discharge process are presented • A case study is presented and used to validate the methodology • Results prove that these methodologies are useful in Carnot Batteries analysis [ABSTRACT FROM AUTHOR]

• A new method for NO oxidation using ClO 2(g) + RPB absorption is proposed. • Smaller doses of ClO 2(g) have comparable oxidation capacity to O 3. • Preliminary oxidation kinetic analysis predicts potential product distribution. • Favorable energy consumption leads to better NOx capture capacity. • ClO 2(g) oxidation with RPB absorption has better cost-effectiveness than scrubber technology. The application of ClO 2(g) for NO oxidation presents a promising approach to improving air pollution control technology. In this study, an integration of ClO 2(g) with absorption using a high-gravity rotating packed bed (HiGee RPB) was proposed for NOx removal. The results showed that ClO 2(g) has a comparable oxidation efficiency (close to 100%) to O 3 in converting NO to NO 2 , while the dosage of ClO 2(g) required was two times smaller than that of O 3. The gas-phase oxidation kinetic analysis between ClO 2(g) -NOx, using an ideal plug flow model, simulated the potential amount of NOx species produced in a short reaction distance in the pipeline. Furthermore, at higher gas-liquid ratios and in high-gravity fields, the effective mass transfer interfacial area for NO 2 absorption was mainly controlled by the liquid film rather than droplet behavior, resulting in decreased absorption capacity. The empirical model for predicting the gas-side mass transfer coefficient confirmed that the interaction between mass transfer performance and chemical absorption was independent. Therefore, selecting the appropriate absorbent is a key factor in achieving high-loading NO 2 concentrations after oxidation by ClO 2(g). Another interesting finding is that balancing system energy consumption and the target treated NOx concentration played a critical role in enhancing the NOx absorption capacity. The cost analysis showed that substituting existing scrubbers with RPB processes could facilitate NOx absorption capacity (g-NOx/kWh) with cost-effectiveness. Overall, this study provides valuable insights into the development of effective and efficient NOx removal technologies, and future research in this area can build on these findings. [ABSTRACT FROM AUTHOR]

• LCA of the castor husk, coffee pulp and Pinus sawdust pyrolysis process was studied. • The separator has an important role in environmental damage in almost all categories. • The pyrolysis process using coffee pulp has the highest environmental impact. • Energy consumption and air emissions are mainly responsible for environmental impacts. • It was demonstrated that the pyrolysis of the coffee pulp is economically viable. Biomasses valorization by pyrolysis is a good option for reducing environmental problems. In this study, the environmental performance of three Mexican biomass valorizations (castor husk, coffee pulp and Pinus sawdust) by the pyrolysis was compared. The environmental impacts of all equipment involved in pyrolysis were evaluated. In addition, the financial viability of pyrolysis technology of coffee pulp was studied. The biomass with the lowest impact for all the selected categories was the Pinus sawdust, followed by castor husk and coffee pulp. The GWP category had values greater than 700 kg CO 2 eq for all the biomass studied. GWP category is caused by the emissions, mainly due to the high amounts of CH 4 and CO 2 released for all the studied biomasses. Furthermore, the equipment with the greatest impact are the separator, the pyrolyzer and the cyclone. Finally, it was observed that even the least favorable biomass with the environment is viable from a financial point of view. [ABSTRACT FROM AUTHOR]

Highlights • Integration of W doped VO 2 for smart wall application. • Real-time control of the wall absorptivity. • Maintain of high solar radiation absorptivity during winter. • Enhancement of cooling energy saving during summer (70%). • Decrease of the electricity bill ($21.6/month) during summer. Abstract Thermochromic materials such as vanadium dioxide ( VO 2 ) have the capability to regulate their infrared reflectivity depending on ambient temperature. Such smart materials are attractive for applications like smart windows and smart roofs. In this paper, we investigate numerically the impact of tungsten (W) doped VO 2 application as a smart outdoor wall layer on the building energy consumption in the Mediterranean climate. Temperature distributions through wall configurations with and without W doped VO 2 were calculated using finite differences method implemented in Matlab environment. Calculations take into consideration dynamic variations of W doped VO 2 absorptivity depending on outdoor temperature variations. Decrement factor, time lag, transmission and peak loads of cooling and heating were calculated. Results have shown that the indoor surface temperature is attenuated during summer by 2–3 °C depending on orientation. Cooling energy saving due to the use of W doped VO 2 in summer is around 70% monthly which is equivalent to save $21.6/month of electricity invoiced amount. During winter, W doped VO 2 maintains the same value of absorptivity as the uninsulated wall. Thus, results show small differences for indoor surface temperature and heating energy consumption. The application of W doped VO 2 in intelligent thermal wall insulation offers a real-time dynamic variation of building's envelope solar absorptivity and makes smart walls concept more feasible. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The pros, cons and progress in full-scale MBR application are summarized. • Statistics on capital and operating costs of MBR are provided and compared with CAS. • Efficiencies in treatment of ordinary and emerging pollutants are reviewed. • Long-term operation stability is discussed in relation to membrane fouling. • Future challenges of MBR application are outlined from multiple perspectives. Abstract Membrane bioreactor (MBR) technology for wastewater treatment has been developed for over three decades. Our latest survey shows that MBR applications for wastewater treatment are still in rapid growth today. This review summarizes the pros, cons and progress in full-scale MBR applications. Critical statistics on the capital cost, operating cost, footprint, energy consumption and chemical consumption of full-scale MBRs are provided, and are compared to those of conventional activated sludge (CAS) processes with/without tertiary treatment. The efficiencies in full-scale treatment of ordinary pollutants (C, N and P), pathogens (bacteria and viruses) and emerging pollutants (e.g., trace organic pollutants) are reviewed. The long-term operation stability of full-scale MBRs is also discussed with several examples provided, with special attention placed on the seasonal variation of membrane fouling. Finally, the future challenges of MBR application are outlined from the perspectives of fouling control, pollutant removal, cost-effectiveness and competitiveness in specific fields of application. [ABSTRACT FROM AUTHOR]

This study assesses the tank-to-wheel savings in fuel consumption and CO 2 emissions as well as vehicle ownership and operating costs of electrified versus conventional midsize passenger vehicles in real-world driving conditions of the greater area of Beirut, Lebanon. This was done by developing representative driving cycles for typical home-to-work commutes during peak and off-peak traffic conditions based on an on-road travel survey. Results show that micro-hybrids are beneficial only in peak times, reducing consumption by 18.3%. Electrified vehicles provide substantial savings of 38.7% for hybrids and 88.6% for plug-in hybrids. However, plug-in and battery electric vehicles are found to contribute significant well-to-tank CO 2 and pollutant emissions due to the dirty electricity mix in Lebanon. In addition, we find that the use of thermal comfort auxiliaries in congested traffic significantly reduces performance of electrified vehicles. Finally, an analysis of vehicle ownership and operating costs is done for the case of Lebanon and results show that hybrid electric vehicles are the preferred technology at low gasoline prices, while plug-in hybrids with a low electric range capability of 20 km become the most competitive at medium to high gasoline prices. [ABSTRACT FROM AUTHOR]

Manual and automated blind controls are typically not included in energy and daylight simulation in part because there is no consensus in the research or practice communities about the way users operate manual blinds or override automated blinds. In order for blind use patterns to become part of energy and daylight simulation best practices, the range of annual energy and daylighting impacts associated with blind use must be understood. This paper addresses these aspects by comparing four leading candidates of manually-controlled blinds plus two automated blind control algorithms using a high-rise office building located in Boise, ID. This study revealed that all four current “manual” blind use algorithm choices perform relatively similarly to automated systems, and surprisingly sometimes even more efficiently. LM-83 currently has the lowest average occlusion during regularly occupied hours, followed by Lightswitch-2002, while Blindswith-A and -B have the highest average occlusion. The IES-recommended manual blind algorithm resulted even in lower average blind occlusion and lighting energy consumption than automated systems. Finally, life-cycle cost analysis was calculated. The results show that the cost savings from interior automated shading system are substantial over a 30-year time horizon, when compared with common passive manual blinds ($25 versus $7.6 Net Present Value per SF glazing area). [ABSTRACT FROM AUTHOR]

In most countries, energy efficiency at the residential level has been largely delegated to the dynamics of real-estate markets after setting a minimum level. This regulatory definition is in certain cases supplemented by energy performance certificates, such as in the case of the European Union. This approach is based on the understanding that avoided energy-consumption costs positively affect the willingness to pay for them, thus leading to higher prices capable of offsetting production costs and thereby encouraging developers. The case of the private housing market in Santiago de Chile was selected as a reference for a developing country in which energy performance certificates, although they exist as an instrument, are not required to be applied in property transactions. However, unlike most of the research performed in developed countries, it is difficult to analyse price formation using methods based on observed preferences in areas in which there are few energy-certified buildings. Using the technique of contingent valuation, such as the method based on stated preferences, enables one to overcome this difficulty. This article investigates willingness to pay for improvements in the energy efficiency of buyers for new homes based on a representative investment/operation cost analysis. This approach has been addressed to open the debate on the convenience of modifying the national construction code and rethinking the energy certification scheme as well as an exploratory study to undercover further research lines to support the aforementioned discussion. The results suggests that there is a number of potential home buyers ready to pay for energy efficiency when they are informed on the cost savings associated to structural modifications and the cost of providing such improvements and such willingness to pay is not monolithic across the respondents, but seems to be influenced by the education level plausibly associated to the purchase power. [ABSTRACT FROM AUTHOR]

Switchgrass (Panicum virgatum L.) is a highly drought-resistant and cold-tolerant perennial energy crop, promising a favourable biomass energy source lately. For cost-effective switchgrass cultivation, physical characteristics and cost factors are critical in encouraging decision-makers to invest in this field. This study aims to develop a methodology to place cost analyses on a spatial basis and relate them with the environmental factors in the Eskisehir province, Türkiye. The results of a former study presenting the suitable lands for switchgrass cultivation in the region, in terms of physical parameters, were used to perform the spatial cost analysis based on the so-called indirect factors, fuel consumption, and crop yield. Regarding the assumed yield amounts and fuel consumption, the findings revealed that switchgrass agriculture on suitable lands would not promise a fixed profitability rate or fixed dry product sales price. Hence, different dry product sales prices were spatially determined and mapped according to five profitability ratios. The sales prices of the dry crop produced from high-suitable agricultural lands were found to be competitive (26.24 USD, 26.28 USD, and 26.31 USD) under free market conditions. Profitability rates varied between 22.79% and 22.66% with an optimistic scenario. It is predicted that 124,680 tons of bioethanol can be obtained with switchgrass production on lands where maximum benefit is provided. The method presented in this study demonstrates that a suitable site selection process can be conducted more holistically when cost-affecting parameters are integrated into spatial analyses and layering processes. • Geospatial characteristics directly affect fuel consumption and crop yield. • Geospatial factors resulted in five different product sales prices and profitability ratios in the study area. • Dry crop sales price was found at 26.24 USD/ton in recommended switchgrass cultivation areas with optimum crop efficiency. • 124,680 tons of bioethanol were calculated to be produced from recommended lands. [ABSTRACT FROM AUTHOR]

The efficient use of local renewable energy sources is a key factor to reach the EU's targets on climate change and renewable energy. In this review, the available technologies to convert solar energy into electrical and thermal energy are investigated. Photovoltaic panels, thermal collectors, heat pumps, solar cooling and energy storage systems are analyzed with a particular attention to their market availability for small-scale applications. Different ways to provide heating, cooling and sanitary hot water from solar source are analyzed and compared from an efficiency, economic and environmental perspective. [ABSTRACT FROM AUTHOR]

Humidification dehumidification (HDH) desalination system is a thermal-based desalination technology that is suitable for small-scale water desalination applications. In this paper, we present an experimental and thermodynamic analysis of the energetic performance of two HDH cycles. The HDH cycles considered are the basic open-air open-water (OAOW) cycle and the modified closed-water open-air (CWOA) cycle with the options of brine recirculation. An experimental investigation is performed on the modified cycle to validate the theoretical model that is used to assess the energetic performance of both the basic and modified cycles. The theoretical model is found to be in a good agreement with the experimental data with a maximum percentage deviation of 5% from the experimental data. Furthermore, limiting cases of the system are explored. Within the limiting cases, the modified cycle recorded about 100% improvement in the energy performance over the basic cycle due to heat recovery process associated with the modified cycle. Additionally, a cost analysis was performed to determine the cost of freshwater production by the presented desalination cycles. Results show that the freshwater price varied from 4.10 to 6.55 $/m 3 and 0.79 to 2.25 $/m 3 for the basic OAOW HDH cycle and the modified CWOA HDH cycle, respectively. [ABSTRACT FROM AUTHOR]

Coke oven gas (COG), a considerable byproduct in coke production, has been utilized as the feedstock for methanol production. A “cradle-to-gate” life cycle assessment (LCA) of COG-based methanol production (COG route) was conducted and compared with the coal and natural gas routes by applying CML 2001 method with GaBi 6.0 software. Besides, the economic analysis of the three methanol routes were performed. The results indicate that COG route shows lower impacts than coal route to all the selected environmental categories. Moreover, the average methanol production cost of COG route is lower than that of coal and natural gas routes by 25.1% and 19.8%, respectively. In COG route, 82.1% of the overall normalized environmental burden occurs at methanol production stage dominated by electricity and steam consumption. The environmental impact of COG route could be reduced by supplying medium-pressure steam from coke dry quenching system for methanol production. This work intends to provide useful insights on the sustainability development of COG utilization in coke industry. [ABSTRACT FROM AUTHOR]

With the help of advanced technologies, district heating systems were gradually improved to increase fuel use efficiency and reduce environmental impacts. Several control strategies focused on the performance improvement of energy generation or distribution in the network. However, most strategies overlooked zone-scaled thermal comfort related to occupant characteristics, and there was lack of studies combined with heat trading concepts. This research presents energy cost analysis of an intelligent network model and heat trading to mitigate increases of energy use and thermal dissatisfaction in a district model. Advanced thermal control algorithms provide optimized supply air conditions responding to occupant characteristics in different buildings. A distribution model contributes to the reduction of energy consumption, and heat trading effects are analyzed to maximize energy cost savings in a district model. In comparison with a conventional model, an intelligent controller improves thermal comfort by about 16.2% for a clinic, 2.4% for an office, and 7.1% for a residential building, respectively. Also, a distribution model with heat trading concept saves total energy costs by about 24.7%, theoretically. In conclusion, the model has advantages that it properly responds to occupant characteristics to mitigate thermal dissatisfaction, and it has a great potential to reduce total energy costs. [ABSTRACT FROM AUTHOR]

Increased use of electric vehicles (EVs) has led to the demand for a larger number of quick-charging units (QCUs) and charging stations (CSs). Long charging queues (congestion) result in inconvenience and high social cost. In this study, QC service is modeled in terms of queueing, and the charging records of QCUs are analyzed to estimate future waiting times. Using these results, an analysis is conducted to determine how the installation of additional QCUs would reduce waiting times for charging. In addition, a cost–benefit analysis is performed on the installation of an additional QCU. To reveal the quick charging (QC) demand, 93,839 QC records in Japan are analyzed. As a result, the inter-arrival and charging times of QC demand can be represented as exponential and normal distributions, respectively. In addition, the expected waiting times for EV charging in the future are also calculated and applied to calculate the allowable waiting time and to perform cost–benefit analysis. Two different evaluations show that the demand criterion for installing an additional QCU is 10 ± 3 vehicles per day per CS. [ABSTRACT FROM AUTHOR]

Energy consumption and wastewater generation in cellulosic ethanol production are among the determinant factors on overall cost and technology penetration into fuel ethanol industry. This study analyzed the energy consumption and wastewater generation by the new biorefining process technology, dry acid pretreatment and biodetoxification (DryPB), as well as by the current mainstream technologies. DryPB minimizes the steam consumption to 8.63 GJ and wastewater generation to 7.71 tons in the core steps of biorefining process for production of one metric ton of ethanol, close to 7.83 GJ and 8.33 tons in corn ethanol production, respectively. The relatively higher electricity consumption is compensated by large electricity surplus from lignin residue combustion. The minimum ethanol selling price (MESP) by DryPB is below $2/gal and falls into the range of corn ethanol production cost. The work indicates that the technical and economical gap between cellulosic ethanol and corn ethanol has been almost filled up. [ABSTRACT FROM AUTHOR]

Households may imperfectly implement energy saving measures. This study identifies two factors resulting in imperfect use of energy-saving technology by households. Households often continue to use old technologies alongside new ones, and the energy-saving technologies have shorter actual lifetimes than their designed lifetimes. These two factors are considered when computing marginal energy conservation cost and marginal CO 2 abatement cost using data collected from a survey of rural households in three provinces in China. The results show that there are cost reduction for most space heating technologies, and their marginal abatement cost under full implementation ranges from −60 to 15 USD/t-CO 2 , while the marginal abatement cost of cooking technologies ranges from 12 to 85 USD/t-CO 2 . The marginal abatement costs of the majority of technologies increased after accounting for the two implementation factors. The marginal abatement cost in the imperfect implementation scenario is higher, with a range of −1 to 15 USD/t-CO 2 for space heating, and 18 to 165 USD/t-CO 2 for cooking. Assuming implementation factors are constant until 2035, annually achievable CO 2 abatement by 2035 is estimated to be 57, 11, and 10 Mt-CO 2 /y in Hebei, Guizhou, and Guangxi Provinces. [ABSTRACT FROM AUTHOR]

The main problems of the conventional biodiesel production technology are high production costs and energy consumption, long residence time, and low efficiency. In order to overcome those problems and to improve the biodiesel production process from the ecological and economical points of view, intensive research activities on the development of new, sustainable technologies are undergone. Microreactors are known to increase the dispersion of two phases considerably as needed for the biodiesel reactants (alcohol and oil). This provides much higher interface area that by elimination of mass-transfer hindrance has shown to lead to shorter reaction time. On this background, this study gives (a) an overview of today’s industrial biodiesel production, (b) the vision of small-scaled, intensified ( micro ) flow reactors as integral element in translatable biodiesel factories, (c) the advantages and disadvantages of the lipase catalysed transesterification process in microreactors as chosen case of study, and (d) cost analysis of biodiesel production for the showcase estimating the performance of industrial-scale in enzyme packed-bed microreactors. [ABSTRACT FROM AUTHOR]

Electrodialysis metathesis (EDM) is a promising technology in synthesis of electrolyte and high-value reclamation of wastewater. The integration of EDM with other processes is a necessary way to maximize the use of raw solution and achieve zero liquid discharge. The exergy analysis is an efficient method to investigate the effective use and loss of energy, and optimize the process. Therefore, a novel integrated process of EDM-RO-MVR was proposed in this work. Membrane area, energy consumption, equipment cost, specific cost, and exergy of a 100 m3/h process were analyzed and discussed. It was shown that the current density has a great influence on the equipment cost of the process, and the proportion of the equipment cost of EDM decreased with the increase of the current density, while the concentration of raw water shown little effect. The specific cost was lowest when the current density was 200 A·m−2. Exergetic analysis showed that the exergy efficiency of the process was 1.5 %, and the largest exergetic loss occurred in the evaporation process. Therefore, it is of great significance to improve the heat transfer efficiency of the evaporator and reduce exergetic loss to improve the energy utilization efficiency of the coupled system. Several similar process fitting for different occasions was also proposed and compared. All above results indicated that EDM-RO-MVR was an economical and feasible methods for high-value conversion of sulfate wastewater and production of potassium sulfate. [Display omitted] • An EDM-RO-MVR integrated process producing K 2 SO 4 from Na 2 SO 4 was proposed and analyzed. • The current density has greater influence on the equipment cost and energy consumption. • The specific cost was lowest when the current density was 200 A·m−2. • The evaporator was a key unit with the largest exergy loss. • The transformations of integrated process could improve the exergy utilization and meet the different production requirement. [ABSTRACT FROM AUTHOR]

Hydrothermal flames are critical to solving preheating problems and enhancing feed degradation in supercritical water oxidation (SCWO) systems. In this work, different hydrothermal flame generation methods including hot water injection, evaporation concentration, and addition of auxiliary fuel are proposed for SCWO of cutting fluids. The proposed systems are simulated using Aspen Plus 8.2, and the simulation model is validated by comparisons with experimental temperature profiles and product properties. A low ratio between the heat source flow and the feed flow (FR) requires a high heat source temperature to keep the hydrothermal flame stable and results in a high electricity consumption, and FR = 2 is chosen as the optimum condition for the SCWO system with hot water injection (SCWOH). The increase in concentration ratio and fuel concentration can effectively reduce the energy consumption for the SCWO systems with evaporation concentration (SCWOE) and addition of auxiliary fuel (SCWOF), respectively. The exergy analysis results indicate that most of exergy inputs are destructed inside the system, and the exergy distribution coefficients of the reactor exceed 80% in the SCWOE and SCWOF. Economic analysis results show the SCWOE has the lowest treatment cost of 95.9 USD/t. • Different hydrothermal flame generation methods for SCWO are proposed and simulated. • A low FR results in a high heat source temperature and electricity consumption. • Increases of concentration ratio and fuel concentration effectively reduce energy consumption. • Exergy distribution coefficients for the reactor exceed 80% in the SCWOE and SCWOF. • The optimal case of SCWOE has the lowest treatment cost of 95.9 USD/t. [ABSTRACT FROM AUTHOR]

The growth of shared mobility has recently challenged the way mobility has traditionally been conceived. In this perspective, this study investigates the Environmental Life Cycle Costs of Urban Air Mobility (UAM) services to evaluate their potential integration with other transport systems, in the three-time horizons (2025, 2030, 2035). The key area of research was focused on the determination of the cost components of UAM required to calculate the unit costs of UAM transportation. To this end, unitary data and the method from a 2017 EC DG MOVE's report on urban accessibility have been adopted. The analysis confirms that most of the cost is related to the aircraft energy consumption during flight, while the rest is used by ground infrastructure. Moreover, the energy cost is strongly correlated with the distance travelled and the size of the aircraft. The longer the flight and the bigger the aircraft, the higher is the energy cost. Complex cost analysis should be able to support decision-makers in the definition of Sustainable Urban Mobility and their principles of integration, participation, monitoring and evaluation. However, it will be necessary to be able to draw on more consolidated and widespread data over time for the creation of Urban plans for Sustainable Mobility. • The costs components of Urban Air Mobility are determined. • The unit costs of the Urban Air Mobility transportation are computed. • Data are based on the in-house expertise on helicopters and aircraft. • The results evidence that the initial start-up phase of the Urban Air Mobility service will be the most expensive. [ABSTRACT FROM AUTHOR]

The paper presents energy performance and environmental impact analysis of cost-optimal renovation solutions conducted in deep renovations of typical large panel-structured apartment buildings located in cold climate conditions. The main objective of the study was to determine the cost-optimal renovation concepts from both the primary energy performance and the total CO 2 emission reduction potential perspectives. The cost-optimal solutions for different main heating systems were determined from over 220 million renovation combinations by using a simulation-based multi-objective optimization (SBMOO) analysis as the main research method. The results demonstrate that the proposed national nearly zero-energy apartment building level can be cost-effectively achieved in deep renovations of large panel apartment buildings, delivering approximately 18–36% return on investment. The results also indicate that up to 90–98 €/m 2 net savings, 850–930 kWh/m 2 reduction in the primary energy consumption and 350–390 kg/m 2 reduction in the total CO 2 emissions over the studied 30-year life-cycle period can be achieved simultaneously, when the cost-optimal renovation concepts are selected. Cost-optimally dimensioned heat pump systems deliver significant cost saving and environmental impact reduction potential compared to improving the energy efficiency of the building envelope, as the delivered energy consumption accounts for more than 90% of the total CO 2 emissions. [ABSTRACT FROM AUTHOR]

A theoretical case study on steam generation has been performed. Different methods of producing steam by vapour compression, direct electrical heating, gas heating, heat pumping, use of waste heat, and a mixture thereof, were theoretically analysed. The final state of the steam had a pressure of 3 bar, which is common for a low pressure industrial steam network. Simulations using EES were performed in order to calculate the energy necessary to generate 1 kg of steam with each method. The CO 2 emission and an approximation of the operating cost for each method was also calculated. The gain of using waste heat at different temperatures was evaluated. Steam generation by vapour compression can reduce the energy consumption by up to a factor of 6. The CO 2 emitted during the production of electricity is crucial in determining the most efficient method when global warming is concerned. Cost analysis shows that gas-fired boilers have the lowest operating cost in the United States, however, vapour compression methods can be cost-competitive depending on the availability of waste heat and the electricity to gas price ratio. Heat pumps are very efficient and have the advantage of running even without heat recovery from waste heat. [ABSTRACT FROM AUTHOR]

This paper explores the potential energy savings of using dynamic cool roofs (DCRs) with seasonally variable reflective surface for various building prototypes when compared to static cool roofs. The analysis conducted demonstrates that the additional energy savings from DCRs depend largely on the climate, insulation level, and reflectance of the roof, as well as but to a lesser extent on the building thermal mass. This study shows that older buildings, with low insulation levels, in colder climates are the best target for retrofit using DCRs. Specifically, the results show that when a variable reflective costing is applied to low insulation buildings, source energy savings can be achieved and range from 4.33 to 19.44 MJ/m 2 (i.e., 1.6–4.9%) for residential units and from 1.17 to 18.00 MJ/m 2 (i.e., 0.3–3.9%) for offices. Based on an economic analysis, it is found that the break-even cost for a variable reflectance coating system with a 22-year life span ranges from 0.80 to 4.84 $/m 2 for residential buildings, and from 0.86 to 4.92 $/m 2 for commercial buildings. [ABSTRACT FROM AUTHOR]

In the daily operation of metro systems, the train scheduling problem aims to find a set of space-time paths for multiple trains that determine their departure and arrival times at metro stations, while train operations are in charge of selecting the best operational speed to satisfy the punctuality and operation costs. Different from the most existing researches that treat these two problems separately, this paper proposes an integrated approach for the train scheduling problem on a bi-direction urban metro line in order to minimize the operational costs (i.e., energy consumption) and passenger waiting time. More specifically, we simultaneously consider (1) the train operational velocity choices that correspond to the energy consumption of trains on each travelling arc, and (2) the dynamic passenger demands at each station for the calculation of total passenger waiting time in the planning horizon. By employing a space-time network representation in the formulations, this complex train scheduling and control problem with dynamic passenger demands is rigorously formulated into two optimization models with linear forms. The first model is an integer programming model that jointly minimizes train traction energy consumption and passenger waiting time. The second model, which is formulated as a mixed-integer programming model, further considers the utilization of regenerative braking energy on the basis of the first model. Due to the computational complexity of these two models, especially for large-scale real-world instances, we develop a Lagrangian relaxation (LR)-based heuristic algorithm that decomposes the primal problem into two sets of subproblems and thus enables to find a good solution in short computational time. Finally, two sets of numerical experiments, involving a relatively small-scale case and a real-world instance based on the operation data of Beijing metro are implemented to verify the effectiveness of the proposed approaches. [ABSTRACT FROM AUTHOR]

In recent years, the boost to the realization of “nearly Zero Energy Buildings” (nZEB) could require so high investment costs which may be not justifiable with the reduced consumptions (and costs) during the use phase. So, even if the estimated potential saving of energy efficiency projects seems to be very high, investors are often discouraged by a high-risk perception, linked to difficulty in knowing the real costs of advanced and innovative technologies, assessing unforeseen costs, or taking into account the significant fluctuations in energy costs. Life Cycle Cost Analysis (LCCA) in buildings could be a useful estimation method, but a large set of input parameters and accurate predictions is required to achieve an effective assessment. Aim of this study is the selection and characterization of the stochastic inputs to be exploited in a probabilistic LCCA to find the cost-optimal energy efficiency measures. We developed a Monte-Carlo based methodology for uncertainty quantification and sensitivity analysis, which combines Global Costs calculation with Building Energy Simulation and we applied it to a building case study, representative of the typical Italian stock. We characterized the stochastic inputs typically involved in the Global Cost method (related to the initial Investment Costs, Annual Costs, Residual Values, and Discount Rates) and analyzed the impact of these parameters on the final results in different renovation scenarios. Results showed that the financial factors (inflation and discount rate) and the energy trend uncertainty are the most influential parameters. Nevertheless, pushing towards nZEB makes it increasingly important the accuracy of investment costs data. [ABSTRACT FROM AUTHOR]

• An integrated energy-economic analysis of Net ZEB office buildings was proposed. • A thorough discussion on the energy balance was provided for Italian climate zones. • Energy grid integrations, self-consumption, storage and losses were analyzed. • The cost assessment of office buildings was performed and compared to state-of-art. • The energy-economic benefit of a new Net ZEB office in Italy was demonstrated. Recently, the built environment has become one of the leading sectors in the challenge of decarbonization and energy consumption reduction. Because of the specific use and the complexity of the typological, architectural, and technical characteristics, non-residential buildings represent a challenge to overcome the nearly Zero Energy Building standard and to achieve the objective of Zero or Net Zero Energy Buildings. It is desirable that the energy produced in situ from renewable sources totally covers the energy demand (ZEB); alternatively, the amount of energy self-produced and dispatched into the grid must be greater than (or equal to) the energy withdrawn from the grid (Net ZEB). At the same time, it is necessary not to neglect the economic aspects. The aim of this work is to propose an integrated energy-economic analysis to demonstrate the actual feasibility of new Net ZEB offices in different Italian climate zones. Thus, the energy analysis of a reference building, based on consolidated and cost-effective envelope and HVAC systems, has been carried out through dynamic simulations. The photovoltaic field located on the roof provides the energy needed for lighting, appliances, and HVAC. The obtained results are the energy demand and the energy production from renewable sources for the case study in each Italian climate zone. Moreover, the paper discusses the complexity of the annual energy balance, considering contributions such as grid integrations, self-consumption, energy stored and losses. Finally, the cost assessment of the proposed building has been carried out and compared to the state-of-art, pointing out the economic feasibility of the Net ZEB. [ABSTRACT FROM AUTHOR]

The manufacture of carbon fibre is an energy intensive proprietary process which has resulted in limited detailed information on the relationship between process parameters, properties, emissions and energy consumption. This experimental study investigates the relationship between these parameters by performing an in-depth analysis of the fibre properties, composition of emitted gases and energy demand for carbon fibre produced using varying processing line speeds and increasing temperatures on a continues manufacturing line, representative of commercial production processes. The time to produce carbon fibre from a polyacrylonitrile (PAN) based precursor can be reduced by up to 33% while mechanical properties are maintained, thus describing a pathway to improved process efficiency with up to 30% less energy demand, leading to a cleaner production. Results however also show that this applies within a limited time and temperature range, while further increase in manufacturing rates leads to yield reduction and decreasing material properties. The findings from this study are scaled virtually to commercial production quantities and converted to energy and financial improvement potentials for the different process setups. This study shows pathways to significantly improve the energy demand, environmental impact and cost, achievable by optimizing the process. [ABSTRACT FROM AUTHOR]

China׳s thermal power industry is now facing some new challenges. The slowing down of the macro economy, the surplus added capacity, low generating hours and the cut of feed-in tariff has now made the decision maker of both government and thermal power enterprises look back and rethink the future development of the whole thermal power industry. In this paper, we give an overall review of China׳s thermal power development based on industry data of the year 2014 and first half year of 2015, followed by a description of the 2015 feed-in tariff adjustment. The feed-in tariff averagely decreased by 0.02 Yuan/kWh, subjecting the thermal power enterprises to great income losses. To give a micro review of how the thermal power perform under such circumstances, we also make an emphatic analysis based on the investigated data of six representative thermal power plants. We can see that the unit benefit varied in the range of 0.03–0.08 Yuan/kWh, and this indicator may be even lower in 2015 as the adjustment of feed-in tariff. At the end, we also give some suggestions both for the government and the thermal power entities. [ABSTRACT FROM AUTHOR]

Comparison of conventional (usually high-pressure sodium (HPS)) and LED luminaires in street/road lighting is not often based on photometrically equivalent lighting solutions and/or correct economic analysis, which may lead to either overestimation or underestimation of savings of any kind. Therefore, this paper presents a correct methodology for the determination of actual energy efficiency and cost indicators in street/road lighting. Both neutral white (NW) and warm white (WW) LEDs, all relevant street/road lighting classes and pole layouts were considered. Analyzing optimal lighting solutions, characterized by the lowest installed power, it was shown that when considering mesopic effects the average energy savings achieved comparing LED (NW and WW) with HPS lighting solutions amounted to 41–62% and 29–59%, respectively, while the ratio between the total costs of the comparable LED (NW and WW) and HPS lighting solutions belonged to the ranges 0.59–1.26 and 0.61–1.14, respectively. An expanded sensitivity analysis of the costs, carried out considering not only the usually taken discount and electricity cost rates, but also the LED package lifetime, showed that the last only slightly influences the total costs. The effects of the use of more efficient LED packages expected in the near future were also analyzed. • Comparison of equivalent HPS, MH and LED street/road lighting solutions. • Methodology for determining actual energy efficiency and cost indicators. • NW/WW LEDs with luminous efficacy up to 160 lm/W and the forthcoming with 190 lm/W. • Study of all street lighting classes/pole layouts under photopic/mesopic conditions. • LEDs are recommended for street/road lighting instead of conventional luminaires. [ABSTRACT FROM AUTHOR]

• We construct a multi-model comparison framework by employing typical IAMs. • We examine how China will contribute to the global 1.5 °C climate target. • China could contribute nearly one-fifth of the global negative emissions by 2100. • The proportion of BECCS could dramatically increase to 29% under the 1.5 °C case. • Energy demand control may rely more on coordination between CCS and clean energy. Enhancing the warm-limiting targets to from below 2 °C to 1.5 °C is of great significance for climate change mitigation, during which the carbon capture and storage (CCS) of China is playing an important role. By framing a multi-model analysis to compare IAMs, this study aims to explore how China can contribute to the global 1.5 °C target, consistent with achieving its carbon neutrality goal. Our multi-model assessment shows that the enhanced targets will advance the reach time of China's carbon peak and neutrality. Under a relatively smooth emission path curve with CCS, China's carbon emissions will decrease sharply by the end of this century. It is estimated that China's negative carbon emissions will contribute nearly one-fifth of the global negative emissions in 2100, with its CCS-captured emissions accounting for 14%. In the energy system, fossil- and biomass-CCS will develop rapidly, with the proportion of biomass with CCS dramatically increasing to 29% and 17% under the 1.5 °C and 2 °C scenarios, respectively. There will be a relatively large gap between the capital and final use costs of CCS, which may weaken the technical advantage when competing with renewables during the life cycle. While the overall control of the energy consumption in the later period will rely more on the proportional adjustment and the coordination between biomass with CCS and clean energy. [ABSTRACT FROM AUTHOR]

This paper presents the photovoltaic technology, the world’s market trends in the past few years and its future map till 2050. The paper shows the PV market development in the world in terms of cumulative installed PV capacity from 2000 to 2013 as actual PV installation in all the world in terms of total installed PV capacity (135 GW), annual installed PV capacity (37 GW) and PV electricity energy generated in each year. According to the forecast of global PV generation, China is expected to be the largest producer of PV electricity soon after 2020. By contrast, the United States’ share is expected to remain at about 15% starting 2020 onwards, while Europe’s share is expected to decrease constantly from 2015 to 2045. The paper also shows that almost all of the energy consumption in Egypt was met by oil and natural gas at 41% and 46% respectively. The remainder was supplied by coal and renewable energy sources. The current demand forecast expects a six percent demand growth per year over the next seven years. Egyptian Electric Holding Company is currently implementing new generation projects to produce 7000 MW over the next few years. For the purpose of designing and sizing PV systems the paper presents the five relevant economic methods of financial analysis that are often used for making building investment decisions. These methods are payback analysis, net benefit analysis, saving-to-investment ratio, adjusted internal rate of return and life-cycle cost. In the same manner, the paper presents two case studies of the financial assessment analyzing PV systems in Egypt. The first case is relates to the on-grid PV 10 MW power plant for different sites, while the second paper describes the finance analysis of a standalone off-grid PV system generating electricity to feed a residential house in rural area of Egypt. [ABSTRACT FROM AUTHOR]

The efficient combined use of water and energy in long distance slurry pipelines is analyzed in light of the total cost function resulting from an energy and mass balance. Given a system throughput and a set of common slurry and flow properties associated with long distance cross country pipelines such as Krieger-type rheology and smooth wall turbulent flow with small yield-to-wall stress, the minimum cost condition is obtained at the minimum feasible transport mean velocity. This condition has been found irrespective of the particular value of the dissipation-to-pump station location difference, provided the required pumping power is positive. [ABSTRACT FROM AUTHOR]

Current research points to a large energy efficiency potential in industry which is still left unexploited. One of the most promising means of reducing energy consumption and related energy costs is implementing an energy management. This paper provides a systematic review of existing academic journal publications on energy management in industry. Five essential key elements of an energy management based on overarching themes are identified within the body of literature (strategy/planning, implementation/operation, controlling, organization and culture) and the specific findings relating to each key element are synthesized. Subsequently a conceptual framework of an energy management is developed which illustrates that a comprehensive approach is necessary in order to effectively exploit the existing energy efficiency potential. Finally implications for further research are described. [ABSTRACT FROM AUTHOR]

A solar desalination system working at sub-atmospheric pressure is investigated. The decrease of the saline water evaporation pressure allows a much reduction of energy required to operate the system. The desalination system consists of a solar basin connected to an external air-cooled condenser and utilizes a vacuum pump to develop the vacuum condition. The experimental results for different seasons are presented. A maximum desalination system efficiency of 40% is obtained. An enhancement of 16.2% and 29.7% in productivity and thermal efficiency, respectively are obtained compared with the conventional solar still. Eventually, a cost analysis is carried out to evaluate the constructed desalination system economically. Based on the analysis of the obtained results, the recommendations for improvement of the constructed system are outlined. [ABSTRACT FROM AUTHOR]