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This research examines the economic implications of different designs for a national low carbon fuel standard (NLCFS) for the road transportation sector. A NLCFS based on the average Carbon Intensity (CI) of all fuels sold generates an incentive for fuel suppliers to reduce the measured CI of their fuels. The economic impacts are determined by the availability of low carbon fuels, estimates of which can vary widely. Also important are the compliance path, reference level CI, and the design of the credit system, particularly the opportunities for trading and banking. To quantitatively examine the implications of a NLCFS, we created the Transportation Regulation and Credit Trading (TRACT) Model. With TRACT, we model a NLCFS credit trading system among profit maximizing fuel suppliers for light- and heavy-duty vehicle fuel use for the United States from 2012 to 2030. We find that credit trading across gasoline and diesel fuel markets can lower the average costs of carbon reductions by an insignificant amount to 98% depending on forecasts of biofuel supplies and carbon intensities. Adding banking of credits on top of trading can further lower the average cost of carbon reductions by 5%–9% and greatly reduce year-to-year fluctuations in credit prices.

Abstract Biodiesel has gained the forefront of our focus on renewable transportation fuels. This article provides a comprehensive review on the sources used as feedstock and their classification based on generation or type (edible, non-edible, waste resources and animal fats) along with a variety of classical and modern oil extraction techniques. The technical aspects of the various biodiesel production methods currently implemented to the best of our knowledge are discussed here, which include in-situ biodiesel production, both catalysed (homogeneous and heterogeneous systems) and uncatalysed classical production approaches, with emphasis on how each of these approaches are affected by their reaction parameters. The review also highlights the observed drawbacks of each process with a view to assessing the implementation of supercritical and superheated technologies as an alternative, economically feasible advancement. Supercritical process (SCP) has shown great prospect in the obtainment of high quality biodiesel from a wide range of high to low grade feedstock with minimal impacts on the presence of water or FFAs (free fatty acids). From available literature it is shown that these do not affect the process significantly, and various other supercritical fluids such as methyl acetate, tert-butyl methyl ether (MTBE) and dimethyl carbonate can also be used to avoid glycerol formation. The process however, suffers from high initial implementation cost being the most prominent drawback, among others like thermal degradation of the fuel. Another promising technique, the superheated vapour technology (SHV) has emerged as an alternative, with limited literature proving the superiority of either of these processes to be inconclusive. In future works, researchers need to look into various aspects such as developing a spiral reactor for heat recovery, using software based optimization for eliminating redundant experiments analysing production cost for industrial scale-up and improving the fuel’s oxidative stability by adding antioxidants for convenient long-term storage and use.

Field study was conducted during winter seasons (November–March) of 2015–2016 and 2016–2017 at the Research Farm of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India, with an aim to investigate the crop productivity, energy and C budget, carbon footprint and economic sustainability of peanut cultivation fertilized with varied levels of nitrogen under polythene mulching. The experiment laid out in split-plot design comprised of two mulching practices as the main-plot treatments and seven doses of N with or without supplementation of Rhizobium bio-fertilizer as the sub-plot treatments. Fertilization with 100% recommended dose of nitrogen (RDN) + Rhizobium under polythene mulching brought about significant enhancement in pod yield over other nutrient management practices. The effects on yield attributing characters were similar to that of pod yield. Energy indices namely net energy gain, energy productivity, energy intensiveness and energy profitability were the highest with 100% RDN + Rhizobium, irrespective of mulching situations. However, the maximum values of specific energy and nutrient energy ratio were recorded when the crop received 50% RDN with and without Rhizobium, respectively, under mulching and non-mulching situations. Human energy profitability was always greater under mulching situations over non-mulching. Total estimated carbon footprints improved with increase in N level from 0 to 100% RDN with Rhizobium under polythene mulching over non-mulching situations. Highest value of C sustainability index was also observed with polythene covering particularly with the application of 100% RDN + Rhizobium. This treatment combination also proved its superiority with respect to economic benefits in peanut cultivation.

Abstract Renewable energy sources (RES) coupled to desalination offers a promising prospect for covering the fundamental needs of power and water in remote regions, where connection to the public electrical grid is either not cost effective or not feasible, and where the water scarcity is severe. Stand-alone systems for electricity supply in isolated locations are now proven technologies. Correct matching of stand-alone power supply desalination systems has been recognized as being crucial if the system is to provide a satisfactory supply of power and water at a reasonable cost. The paper covers plants installed since 1990 on the coupling of the two technologies. The main driver promoting the take up of this technology is that water is a limiting factor for many countries in the Mediterranean region. This paper presents the two technologies, RES desalination, and describes the most promising couplings such as PV–reverse osmosis, wind-mechanical-vapor compression, geothermal-multieffect distillation, etc as well as technologies selection guidelines. Also, included applications and lessons learned from specific applications as well as data on the economics. RES for desalination is an important challenge and useful work has been done. However in order to provide practical viable plants, much remains to be done.

SummaryStudies investigated the patient‐care (in‐hospital) and outside‐the‐hospital energy consumptions for delivering the hemodialysis (HD) service. A life cycle inventory methodology was used for this patient‐based analysis for two hospitals located in Wichita, Kansas. It was found that, for both hospitals, the actual HD machines consumed approximately 3.5 kilowatt‐hours (kWh) of electrical energy per HD, only 8% to 16% of the total energy used for delivering the HD service (in hospital). This increases to 9.6 to 28.9 kWh of hospital billable energy for the whole system of HD machine, auxiliaries, and dialysis water treatment. Converting these hospital direct electrical energy values to natural resource energy (nre) then adding the cradle‐to‐gate natural resource energy for the manufacturing and supply chain of all the HD consumables, the total is 78 to 149 kWh nre/HD. The nre measures all the direct fuel burned to generate energy and is thus directly related to emissions to the air, water, and land and is a direct secondary impact on public health from HD. The ratio of outside‐the‐hospital energy to direct hospital HD electrical energy consumption is 4:1 to 7:1, so a broader base exists for improvement than just the hospital.

Abstract Recent results of GDF SUEZ Research and Innovation Division (RID) activities on Compressed Natural Gas (CNG) vehicles are depicted in this paper: • The prototype “Toyota Prius II Hybrid CNG Vehicle”, developed with IFP Energies Nouvelles, combines a natural gas thermal engine with a hybrid electric motorization. After optimization, CO2 emissions, measured on chassis dynamometer, were 76 g/km on NEDC cycle. • The use of raw biogas in CNG Vehicle has been explored. These tests have shown that raw biogas (not upgraded) can be used as a fuel, if blended with natural gas. In fact, the use of raw biogas can be envisaged in dedicated CNG engines, if new engine technologies (lean CNG combustion) are developed. In such a case natural gas can be blended with up to 70% volume of not upgraded biogas. • The potential reduction of greenhouse gases (GHG) emissions related both to the optimization of the CNG vehicle and to the use of biomethane as a vehicle fuel has been evaluated. GHG emissions from CNG vehicles (mono-fuel and hybrid) may be significantly lower than emissions of gasoline vehicles: around 17% lower in the case of dedicated CNG Vehicle and up to 51% lower in the case of hybrid CNG vehicles. In addition, biomethane (from the anaerobic digestion of waste) brings the GHG emission levels, over the course of the life cycle, down to more than 80% compared to a gasoline vehicle. Emission levels are lowered by 87% in the case of the Toyota Prius CNG Hybrid prototype fuelled by biomethane produced from waste (in comparison to a gasoline vehicle). Thus, biomethane allows a reduction of GHG emissions far below the minimum required by the European Directive on the Promotion of Renewable Energy Sources (2009/28/EC). These results have shown that the combination of optimized and innovative engines with the use of biomethane as a fuel permits to significantly reduce the GHG emissions.

Yard waste is either dumped or is being openly burned to get rid of it, instead of using it as a valuable renewable energy source. In this study, hydrothermal carbonization of yard waste was conducted to valorize it as a solid bio fuel, using a batch reactor. The effect of process parameter on yield, energy and physicochemical properties of the valorized solid bio fuel (hydrochar) was examined in this study by varying reaction temperature (160-200 °C for 2 h) and reaction time (2-24 h at 200 °C). The calorific value of hydrochar was within a range of 17.72-24.59 MJ/kg as compared to 15.37 MJ/kg for untreated yard waste. Hydrochar mass yield decreased from 78.6% at operating temperature - time of 160 °C -2 h to 45.6% at 200 °C -24 h. The plot of atomic ratios (H/C and O/C) demonstrates improvement in the coalification process which was mainly governed by decarboxylation and dehydration reactions. The grindability of the prepared hydrochar was comparable to that of coal. Hydrochar produced at lower reaction condition (160-200 °C at 2 h) have better flowability as compared to that produced at higher reaction condition (4-24 h at 200 °C). The reaction time longer than 12 h has a minimal effect on the yield, energy and physicochemical properties of hydrochar. Increasing reaction time and temperature improved the ignition and burnt temperature of hydrochar. All reaction condition has an energy ratio (energy output to energy input) of more than one making HTC process a net energy producer.

Abstract In this paper, we examine the time-varying causal relationship between green bonds and other assets including US conventional bonds, WilderHill clean energy (equity) index, and CO2 emission allowances price during the period spanning from 30 July 2014 to 10 February 2020. We apply the novel time-varying Granger causality test (Shi et al. 2018) based on the recursive evolving algorithm introduced by Phillips et al. (2015a, 2015b) for controlling financial bubbles to detect real–time causality, detecting possible changes in the causal direction and dating financial turbulences, The study based on this algorithm reveals a significant causality running from the US 10-year Treasury bond index to green bonds starting from the end of the year 2016 until the end of the sample period. Besides, we find that the link CO2 emission allowances price causing green bonds is significant from the beginning of the sample period to the end of the year 2015. Furthermore, by using the recursive-evolving causality algorithm of the Shi et al. (2018) test, we find that the causality running from the clean energy index to green bonds is very limited to the year 2019. On the other hand, there is no significant causality running from green bonds to all considered assets, indicating no predictive power for this asset in its proper domain, which is not yet examined in the literature.

Abstract Climate change impacts may manifest via multiple pathways, often leading to a shortage of resources, reduction in production capacities, or reduction in available labor inputs that are vital for economic activities. Effective climate change adaptation strategies are needed to determine the optimal allocation of scarce resources, commodities or capital under crisis conditions to minimize the economic consequences. In such cases, it is necessary to account for structural properties of economic systems to ensure that rational distribution policies are implemented. Input–output models are used to illustrate interdependencies among economic sectors and to assess both direct and indirect effects of disruptive events. Alternatively, these interdependencies may be exploited for developing effective recovery efforts to minimize the ripple effects of a crisis. In this paper, a process graph representation of the input–output model is developed to generate a rational procedure for the allocation of scarce resources, commodities or capital during crisis conditions. The process graph model is a graph-theoretic approach originally developed for chemical process design applications. The analogous problem structure allows it to be used for the input–output system. The method is demonstrated through several case studies to identify allocation policies geared towards reducing the impact of disruptions attributed to critical resources, commodities, or capital. Results show that depending on the economic structure, the optimal allocation of scarce resources, commodities or capital will satisfy the final demands of some economic sectors and reduce the production capacity of others in order to minimize the reduction of total gross domestic product. Though similar results can be obtained through traditional mathematical programming models, the process graph platform has the advantage to visually present the distribution of scarce resources, commodities or capital within the system. This work is a first attempt to implement the process graph approach in the fields of economics and climate change adaptation. In conclusion, the process graph based approach developed in this work can be used to provide policymakers with insights in developing appropriate risk mitigation plans associated with climate change-induced crisis conditions. Potential applications include both the development of disaster preparedness measures for anticipated disruptions, as well as the implementation of real-time emergency response in the midst of a crisis.