Harmonised life-cycle indicators of nuclear-based hydrogen

When comparing the life-cycle environmental performance of hydrogen energy systems, significant concerns arise due to potential methodological inconsistencies between case studies. In this regard, protocols for harmonised life cycle assessment (LCA) of hydrogen energy systems are currently available to mitigate these concerns. These protocols have already been applied to conventional hydrogen from steam methane reforming as well as to a large number of both fossil and renewable hydrogen options, allowing robust comparisons between them. However, harmonised life-cycle indicators of nuclear-based hydrogen options are not yet available in the literature. This study fills this gap by using the recently developed software GreenH₂armony® to calculate the harmonised carbon, energy and acidification footprints of nuclear-based hydrogen produced through different pathways (viz., low-temperature electrolysis, high-temperature electrolysis, and thermochemical cycles). Overall, the harmonised case studies of nuclear-based hydrogen show a generally good performance in terms of carbon footprint and acidification, but an unfavourable performance in terms of non-renewable energy footprint.     

Harmonising methodological choices in life cycle assessment of hydrogen: A focus on acidification and renewable hydrogen

The environmental sustainability of hydrogen energy systems is often evaluated through Life Cycle Assessment (LCA). In particular, environmental suitability is usually determined by comparing the life-cycle indicators calculated for a specific hydrogen energy system with those of a reference system (e.g., conventional hydrogen from steam methane reforming, SMR-H₂). In this respect, harmonisation protocols for comparative LCA of hydrogen energy systems have recently been developed in order to avoid misleading conclusions in terms of carbon footprints and cumulative energy demand. This article expands the scope of these harmonisation initiatives by addressing a new life-cycle indicator: acidification. A robust protocol for harmonising the acidification potential of hydrogen energy systems is developed and applied to both SMR-H₂ and a sample of case studies of renewable hydrogen. According to the results, unlike other energy systems, there is no correlation between acidification and carbon footprint in the case of hydrogen energy systems, which prevents the estimation of harmonised acidification results from available harmonised carbon footprints. Nevertheless, an initial library of harmonised life-cycle indicators of renewable hydrogen is now made available.     

Dynamic simulation and lifecycle assessment of hydrogen fuel cell electric vehicles considering various hydrogen production methods

In this research study, a real model of a hydrogen fuel cell vehicle is simulated using Simcenter Amesim software. The software used for vehicle simulation enabled dynamic simulation, resulting in more precise simulation. Furthermore, considering that fuel cell degradation is one of the significant challenges confronting fuel cell vehicle manufacturers, we examined the impact of fuel cell degradation on the performance of hydrogen vehicles. According to the findings, a hydrogen vehicle with a degraded fuel cell consumes 14.3% more fuel than a fresh fuel cell hydrogen vehicle. A comprehensive life cycle assessment (LCA) is also performed for the designed hydrogen vehicle. The results of the hydrogen vehicle life cycle assessment are compared with a gasoline vehicle to fully understand the effect of hydrogen vehicles in reducing air emissions. The methods considered for hydrogen production included natural gas reforming, electrolysis, and thermochemical water splitting method. Furthermore, because the source of electricity used for electrolysis has a significant impact on the life cycle emission of a hydrogen vehicle, three different power sources were considered in this assessment. Finally, while a hydrogen vehicle with a degraded fuel cell emits lower carbon dioxide (CO₂) than a gasoline vehicle, the emitted CO₂ from this vehicle using hydrogen from electrolysis is approximately 25% higher than that of a new hydrogen vehicle.     

Life cycle assessment of hydrogen fuel cell and gasoline vehicles

A life cycle assessment of hydrogen and gasoline vehicles, including fuel production and utilization in vehicles powered by fuel cells and internal combustion engines, is conducted to evaluate and compare their efficiencies and environmental impacts. Fossil fuel and renewable technologies are investigated, and the assessment is divided into various stages.     

Comparative lifecycle assessment of hydrogen fuel cell,electric, CNG,and gasoline-powered vehicles under real driving conditions

Since transportation is one of the major contributors of global warming and air pollution, developing low-emission vehicles can significantly result in a more sustainable environment. In this research study, four different types of personal vehicles, including gasoline-fueled, CNG-fueled, electric, and hydrogen fuel cell vehicles (FCV) vehicles, are considered to analyze the role of personal vehicles in transportation. In the first step, based on common vehicles, all selected vehicles are simulated in the Simcenter Amesim Software. The primary aim of the modeling is to investigate the performance of each vehicle under the NYC driving conditions. The results indicate that under the selected driving cycle, CNG and gasoline-fueled vehicles consume 165.44g and 174.07g of CNG and gasoline in each driving cycle respectively, while the electric and hydrogen fuel cell vehicles consume 1.51% of the battery pack capacity and 26.47 g of hydrogen per driving cycle, respectively. In the next step, to study the vehicles' life cycle assessments (LCA), the GREET software is implemented to investigate the overall performance of the vehicles from the cradle to the grave. Based on the LCA results, CO₂, CO, NOx, GHG, and SOx pollution are examined for all selected vehicles, in which the FCV indicates the best behavior. Finally, the emitted CO₂ for FCV in comparison with gasoline-fueled, CNG-fueled, and EV vehicles were 75.87%, 73.42%, and 35.5% lower, respectively.     

A well to pump life cycle environmental impact assessment of some hydrogen production routes

In the present study, a comparative well to pump life cycle assessment is conducted on the hydrogen production routes of water electrolysis, biomass gasification, coal gasification, steam methane reforming, hydrogen production from ethanol and methanol. The CML 2001 impact assessment methodology is employed for assessment and comparison. Comparatively higher life cycle Carbon dioxide and Sulphur oxide emissions of 27.3 kg/kg H₂ and 50.0 g/kg H₂ respectively are determined for the water electrolysis hydrogen production route via U.S. electricity mix. In addition, the life cycle global warming potential of this route (28.6 kg CO_2eq/kg H₂) is found to be comparatively higher than other routes followed by coal gasification (23.7 kg CO_2eq/kg H₂)_. However, the ethanol based hydrogen production route is estimated to have comparatively higher life cycle emissions of nitrogen dioxide (19.6 g/kg H₂) and volatile organic compounds (10.3 g/kg H₂). Moreover, this route is determined to have a comparatively higher photochemical ozone creation potential of 0.0045 kg-ethene_eq/kg H₂ as well as eutrophication potential of 0.0043 kg PO_4eq/kg H_2. The results of this study are comparatively discussed to signify the importance of life cycle assessment in comparing the environmental sustainability of hydrogen production routes.     

Exploratory environmental impact assessment of the manufacturing and disposal stages of a new PEM fuel cell

This study presents an Exploratory Environmental Impact Assessment (EEIA) of the manufacturing process of a Polymer Electrolyte Membrane (PEM) fuel cell mounted in a cargobike, a three-wheel assisted-pedalling vehicle that is equipped to carry small loads, from a Life Cycle Assessment (LCA) approach. Results show that metals (both their production and processing) are the main contributors to the global warming and fossil energy use impact categories. Impact of platinum is considerable in acidification impact category, due to the large emissions of sulphur oxides produced during the extraction of the material. If recycled platinum is considered, a decrease of 20% could be achieved in this impact category.     

Life cycle cost of conventional,battery electric,and fuel cell electric vehicles considering traffic and environmental policies in China

Electric vehicles (EVs) are considered a promising alternative to conventional vehicles (CVs) to alleviate the oil crisis and reduce urban air pollution and carbon emissions. Consumers usually focus on the tangible cost when choosing an EV or CV but overlook the time cost for restricting purchase or driving and the environmental cost from gas emissions, falling to have a comprehensive understanding of the economic competitiveness of CVs and EVs. In this study, a life cycle cost model for vehicles is conducted to express traffic and environmental policies in monetary terms, which are called intangible cost and external cost, respectively. Battery electric vehicles (BEVs), fuel cell electric vehicles (FCEVs), and CVs are compared in four first-tier, four new first-tier, and 4 s-tier and below cities in China. The comparison shows that BEVs and FCEVs in most cities are incomparable with CVs in terms of tangible cost. However, the prominent traffic and environmental policies in first-tier cities, especially in Beijing and Shanghai, greatly increase the intangible and external costs of CVs, making consumers more inclined to purchase BEVs and FCEVs. The main policy benefits of BEVs and FCEVs come from three aspects: government subsidies, purchase and driving restrictions, and environmental taxes. With the predictable reduction in government subsidies, traffic and environmental policies present important factors influencing the competitiveness of BEVs and FCEVs. In first-tier cities, BEVs and FCEVs already have a competitive foundation for large-scale promotion. In new first-tier and second-tier and below cities, stricter traffic and environmental policies need to be formulated to offset the negative impact of the reduction in government subsidies on the competitiveness of BEVs and FCEVs. Additionally, a sensitivity analysis reveals that increasing the mileage and reducing fuel prices can significantly improve the competitiveness of BEVs and FCEVs, respectively.     

Comparative economic and environmental benefits of ownership of both new and used light duty hydrogen fuel cell vehicles in Japan

We present a novel study of the differential total costs of ownership and marginal cost of life cycle emissions abatement for owners of both new and used light duty fuel cell and internal combustion engine vehicles in Japan. We find the emergence of used FCVs in the fleet significantly improves the economic and emissions savings over ICEVs. The cumulative life cycle GHG emissions reductions rapidly increase when FCVs exceed 55%–70% of total LDVs. Life cycle emissions in the vehicle fleet increase 40% if hydrogen is produced from SMR with CCS rather than from solar or wind based electrolysis. Fuel cell cost and electrolyser efficiency are key factors in achieving benefits. Finally, if the early time growth of FCVs to 2030 can be maintained near 50% the government 2050 emissions reduction target of 80% reduction from a 2013 base can be achieved.     

The effects of driving patterns and PEM fuel cell degradation on the lifecycle assessment of hydrogen fuel cell vehicles

This research paper mainly deals with the realistic simulation of hydrogen fuel cell vehicles and the development of a lifecycle assessment (LCA) tool to calculate and compare the environmental impacts of hydrogen fuel cell passenger vehicles with conventional vehicles. Since fuel cell vehicles are equipped with regenerative braking, they have strong potential to recover an ample portion of the energy being wasted in the braking system. Thus, the driving cycle can significantly affect the performance of fuel cell vehicles. In order to investigate the effect of driving patterns, several driving patterns are considered, and both vehicle fuel economy and lifecycle emissions are calculated and compared. Fuel cell degradation, on the other hand, is another major problem fuel cell vehicles face. This is mainly caused by the starts/stops, acceleration/deceleration, membrane humidity variation and a high load of the engine. When the vehicle operates on various driving patterns, the fuel cell will degrade which eventually affects the fuel economy. The effect of fuel cell degradation is also investigated for these driving patterns, and the results are compared. The results showed that the highway driving cycle has the lowest total lifecycle emission compared to New York city driving cycle, the city of Surrey (CoS) driving cycle, and the UDDS driving cycles. The results also indicate that fuel cell degradation undesirably affected the average fuel economy of the vehicle for about 23%.     

Realistic simulation of fuel economy and life cycle metrics for hydrogen fuel cell vehicles

The present work contributes an engineered life cycle assessment (LCA) of hydrogen fuel cell passenger vehicles based on a real‐world driving cycle for semi‐urban driving conditions. A new customized LCA tool is developed for the comparison of conventional gasoline and hydrogen fuel cell vehicles (FCVs), which utilizes a dynamic vehicle simulation approach to calculate realistic, fundamental science based fuel economy data from actual drive cycles, vehicle specifications, road grade, engine performance, fuel cell degradation effects, and regenerative braking. The total greenhouse gas (GHG) emission and life cycle cost of the vehicles are compared for the case of hydrogen production by electrolysis in British Columbia, Canada. A 72% reduction in total GHG emission is obtained for switching from gasoline vehicles to FCVs. While fuel cell performance degradation causes 7% and 3% increases in lifetime fuel consumption and GHG emission, respectively, regenerative braking improves the fuel economy by 23% and reduces the total GHG emission by 10%. The cost assessment results indicate that the current FCV technology is approximately $2,100 more costly than the equivalent gasoline vehicle based on the total lifetime cost including purchase and fuel cost. However, prospective enhancements in fuel cell durability could potentially reduce the FCV lifetime cost below that of gasoline vehicles. Overall, the present results indicate that fuel cell vehicles are becoming both technologically and economically viable compared with incumbent vehicles, and provide a realistic option for deep reductions in emissions from transportation. Copyright © 2016 John Wiley & Sons, Ltd.     

Prospects and impediments for hydrogen and fuel cell vehicles in the transport sector

Hydrogen and fuel cell vehicles are often discussed as crucial elements in the decarbonisation of the transport systems. However, in spite of the fact that hydrogen and fuel cell vehicles have a long history, they are still seen only as a long-term mobility option. The major objective of this paper is to analyse key barriers to the increasing use of hydrogen and fuel cell vehicles. A special focus is put on their economic performance, because this will be most crucial for their future deployment. Mobility costs are calculated based on the total cost of ownership, and future developments are analysed based on technological learning. The major conclusion is that to achieve full benefits of hydrogen and fuel cells in the transport sector, it is necessary to provide stabile, long-term policy framework conditions, as well as to harmonize actions across regions to be able to take advantage of economies of scale.     

A study on the environmental aspects of hydrogen pathways in Korea

In this study, the environmental aspects of H₂ pathways are analyzed according to plausible H₂ production methods, production capacity, and distribution options in Korea, using life cycle assessment (LCA) methodology. The target H₂ pathways analyzed are H₂ via naphtha steam reforming (Naphtha SR), H₂ via natural gas steam reforming (NG SR), H₂ via liquefied petroleum gas steam reforming (LPG SR), H₂ via water electrolysis with wind power (WE[Wind]), and H₂ via water electrolysis with Korea electricity mix (WE[KEM]). The results are then compared with those of conventional fuels (gasoline, diesel, and LPG) to identify which H₂ pathway has less environmental impact than the conventional fuels.     

Comparison of well-to-wheels energy use and emissions of a hydrogen fuel cell electric vehicle relative to a conventional gasoline-powered internal combustion engine vehicle

The operation of hydrogen fuel cell electric vehicles (HFCEVs) is more efficient than that of gasoline conventional internal combustion engine vehicles (ICEVs), and produces zero tailpipe pollutant emissions. However, the production, transportation, and refueling of hydrogen are more energy- and emissions-intensive compared to gasoline. A well-to-wheels (WTW) energy use and emissions analysis was conducted to compare a HFCEV (Toyota Mirai) with a gasoline conventional ICEV (Mazda 3). Two sets of specific fuel consumption data were used for each vehicle: (1) fuel consumption derived from the U.S. Environmental Protection Agency's (EPA's) window-sticker fuel economy figure, and (2) weight-averaged fuel consumption based on physical vehicle testing with a chassis dynamometer on EPA's five standard driving cycles. The WTW results show that a HFCEV, even fueled by hydrogen from a fossil-based production pathway (via steam methane reforming of natural gas), uses 5%–33% less WTW fossil energy and has 15%–45% lower WTW greenhouse gas emissions compared to a gasoline conventional ICEV. The WTW results are sensitive to the source of electricity used for hydrogen compression or liquefaction.     

The influence of degradation effects in proton exchange membrane fuel cells on life cycle assessment modelling and environmental impact indicators

Although proton exchange membrane fuel cell (PEMFC) systems are expected to have lower environmental impacts in the operational phase, compared to conventional energy conversion systems, there are still certain economic, operational, and environmental setbacks. Durability under a wide range of operating conditions presents a challenge because degradation processes affect the PEMFC efficiency. Typically, life cycle assessment (LCA) of PEMFC systems do not include performance degradation. Thus, a novel semi-empirical PEMFC model is developed, which includes degradation effects caused by different operational regimes (dynamic and steady-state). The model is integrated into LCA through life cycle inventory (LCI) to achieve a more realistic and accurate evaluation of environmental impacts. Verification of the model clearly showed that the use of existing LCI models underestimates the environmental impacts. This is especially evident when green hydrogen is used in PEMFC operational phase, where manufacturing phase and maintenance (stack replacements) become more influential. Input parameters of the model can be modified to reflect technological improvements (e.g. platinum loading or durability) and evaluate the effects of future scenarios.     

The analysis on energy and environmental impacts of microalgae-based fuel methanol in China

The whole life of methanol fuel, produced by microalgae biomass which is a kind of renewable energy, is evaluated by using a method of life cycle assessment (LCA). LCA has been used to identify and quantify the environment emissions and energy efficiency of the system throughout the whole life cycle, including microalgae cultivation, methanol conversion, transport, and end-use. Energy efficiency, defined as the ratio of the energy of methanol produced to the total required energy, is 1.24, the results indicate that it is plausible as an energy producing process. The environmental impact loading of microalgae-based fuel methanol is 0.187mPET₂₀₀₀ in contrast to 0.828mPET₂₀₀₀ for gasoline. The effect of photochemical ozone formation is the highest of all the calculated categorization impacts of the two fuels. Utilization of microalgae an raw material of producing methanol fuel is beneficial to both production of renewable fuels and improvement of the ecological environment. This Fuel methanol is friendly to the environment, which should take an important role in automobile industry development and gasoline fuel substitute.     

Modeling the life cycle energy and environmental performance of amorphous silicon BIPV roofing in the US

Building integrated photovoltaics (BIPV) perform traditional architectural functions of walls and roofs while also generating electricity. The displacement of utility generated electricity and conventional building materials can conserve fossil fuels and have environmental benefits. A life cycle inventory model is presented that characterizes the energy and environmental performance of BIPV systems relative to the conventional grid and displaced building materials. The model is applied to an amorphous silicon PV roofing shingle in different regions across the US. The electricity production efficiency (electricity output/total primary energy input excluding insolation) for a reference BIPV system (2kW_p PV shingle system with a 6% conversion efficiency and 20 year life) ranged from 3.6 in Portland OR to 5.9 in Phoenix, AZ indicating a significant return on energy investment. The reference system had the greatest air pollution prevention benefits in cities with conventional electricity generation mixes dominated by coal and natural gas, not necessarily in cities where the insolation and displaced conventional electricity were greatest.     

Life cycle assessment of the transmission network in Great Britain

Analysis of lower carbon power systems has tended to focus on the operational carbon dioxide (CO₂) emissions from power stations. However, to achieve the large cuts required it is necessary to understand the whole-life contribution of all sectors of the electricity industry. Here, a preliminary assessment of the life cycle carbon emissions of the transmission network in Great Britain is presented. Using a 40-year period and assuming a static generation mix it shows that the carbon equivalent emissions (or global warming potential) of the transmission network are around 11 gCO_2-eq/kWh of electricity transmitted and that almost 19 times more energy is transmitted by the network than is used in its construction and operation. Operational emissions account for 96% of this with transmission losses alone totalling 85% and sulphur hexafluoride (SF₆) emissions featuring significantly. However, the CO₂ embodied within the raw materials of the network infrastructure itself represents a modest 3%. Transmission investment decisions informed by whole-life cycle carbon assessments of network design could balance higher financial and carbon ‘capital’ costs of larger conductors with lower transmission losses and CO₂ emissions over the network lifetime. This will, however, necessitate new regulatory approaches to properly incentivise transmission companies.     

Environmental life cycle feasibility assessment of hydrogen as an automotive fuel in Western Australia

A life cycle assessment has been undertaken in order to determine the environmental feasibility of hydrogen as an automotive fuel in Western Australia. The criterion for environmental feasibility has been defined as having life cycle impacts equal to or lower than those of petrol. Two hydrogen production methods have been analysed. The first is steam methane reforming (SMR), which uses natural gas (methane) as a feedstock. The second method analysed is alkaline electrolysis (AE), a mature technology that uses water as a feedstock. The life cycle emissions and impacts were assessed per kilometre of vehicle travel.