Assessment of primary impacts of a hydrogen economy in New Zealand using UniSyD

Small economies such as New Zealand risk significant economic hardship without careful evaluation of alternatives to petroleum-based transportation due to the adverse effects of climate change and depleting international oil reserves. This paper uses an integrated multi-regional multi-fleet system dynamics model of New Zealand's energy economy to assess the primary impacts of alternative vehicle fleet technologies. Results suggest that hydrogen fuelled HICEs and FCVs may offer significantly greater economic savings than BEVs due to a much lower capital cost. Under our Base Case, 65% of the light fleet are HICEs and FCVs and 5% BEVs. Excluding hydrogen vehicles from the vehicle fleet can result in an average annual cost of US$562 per vehicle between 2015 and 2050. Co-production of hydrogen and electricity using coal gasification with carbon capture and storage is the dominant long term hydrogen production technology.     

Cost-effective energy carriers for transport – The role of the energy supply system in a carbon-constrained world

The aim of this study is to examine how the options for producing electricity, fuels, and heat in a carbon-constrained world affect the cost-effectiveness of a range of fuels and propulsion technologies in the transportation sector. GET 7.0, a global energy system model with five end-use sectors, is used for the analysis. We find that an energy system dominated either by solar or by nuclear tends to make biofuels in plug-in hybrids cost-effective. If coal with carbon capture and storage (CCS) dominates the energy system, hydrogen cars, rather than plug-in hybrids tend to become cost-effective. Performing a Monte Carlo simulation, we then show that the general features of our results hold for a wide range of assumptions for the costs of vehicle propulsion technologies (e.g., batteries and fuel cells). However, sufficiently large changes in say the battery costs may overturn the impact of changes in the energy supply system, so that plug-in hybrid vehicles become cost-effective even if coal with CCS dominate the energy supply. We conclude that analyses of future energy carriers and propulsion technologies need to consider developments in the energy supply system.     

Potential opportunities and impacts of a hydrogen economy for the Australian minerals industry

The hydrogen economy is one of the key areas of interest for the reduction of societal greenhouse gas emissions. However, the potential for impact of hydrogen technologies in the transition to a hydrogen economy will vary across the different industrial sectors depending on the source and usage of current energy sources. This paper presents a broad examination of hydrogen economy opportunities and impacts for the minerals industry in Australia. The usage of hydrogen and fuel cell technology in the mining and metals production sub-sectors has differing potential as metallurgical and heavy-duty mobile energy consumption may not be feasibly substituted with hydrogen. This examination indicates a potential of 12–13% reduction in primary energy usage by the minerals industry, with a resulting reduction in greenhouse gas emissions of 9–12% without carbon capture and storage (CCS), or 53–60% reduction with CCS. Other impacts on the industry may include an increased demand for minerals to produce fuel cells, catalysts and infrastructure. Minimal local reserves of platinum group metals are likely to be the limiting capacity factor.     

The production of hydrogen fuel from renewable sources and its role in grid operations

Understanding the scale and nature of hydrogen's potential role in the development of low carbon energy systems requires an examination of the operation of the whole energy system, including heat, power, industrial and transport sectors, on an hour-by-hour basis. The Future Energy Scenario Assessment (FESA) software model used for this study is unique in providing a holistic, high resolution, functional analysis, which incorporates variations in supply resulting from weather-dependent renewable energy generators. The outputs of this model, arising from any given user-definable scenario, are year round supply and demand profiles that can be used to assess the market size and operational regime of energy technologies. FESA was used in this case to assess what - if anything - might be the role for hydrogen in a low carbon economy future for the UK.In this study, three UK energy supply pathways were considered, all of which reduce greenhouse gas emissions by 80% by 2050, and substantially reduce reliance on oil and gas while maintaining a stable electricity grid and meeting the energy needs of a modern economy. All use more nuclear power and renewable energy of all kinds than today's system. The first of these scenarios relies on substantial amounts of ‘clean coal’ in combination with intermittent renewable energy sources by year the 2050. The second uses twice as much intermittent renewable energy as the first and virtually no coal. The third uses 2.5 times as much nuclear power as the first and virtually no coal.All scenarios clearly indicate that the use of hydrogen in the transport sector is important in reducing distributed carbon emissions that cannot easily be mitigated by Carbon Capture and Storage (CCS). In the first scenario, this hydrogen derives mainly from steam reformation of fossil fuels (principally coal), whereas in the second and third scenarios, hydrogen is made mainly by electrolysis using variable surpluses of low-carbon electricity. Hydrogen thereby fulfils a double facetted role of Demand Side Management (DSM) for the electricity grid and the provision of a ‘clean’ fuel, predominantly for the transport sector. When each of the scenarios was examined without the use of hydrogen as a transport fuel, substantially larger amounts of primary energy were required in the form of imported coal.The FESA model also indicates that the challenge of grid balancing is not a valid reason for limiting the amount of intermittent renewable energy generated. Engineering limitations, economic viability, local environmental considerations and conflicting uses of land and sea may limit the amount of renewable energy available, but there is no practical limit to the conversion of this energy into whatever is required, be it electricity, heat, motive power or chemical feedstocks.     

Hydrogen import pathway comparison framework incorporating cost and social preference: Case studies from Australia to Japan

Recent proposals to produce and import hydrogen from Australia to Japan for electricity generation raise questions about how to compare the costs and feasibilities of different hydrogen import pathways. This paper establishes a framework for the comparison of technological, economic, and social costs and feasibility. The framework is then applied to 3 potential production and import case studies. First, a benchmark case study is considered which uses Australian brown coal from the Latrobe Valley combined with carbon capture and sequestration (CCS) technology. The second and third comparative case studies use renewable energy and electrolysis near port facilities in Karratha, Western Australia, using solar power exclusively as the renewable energy source, and Gladstone, Queensland, using a combination of onshore wind and solar‐based generation. The study finds that comparative pilot project generation costs for the brown coal pathway are between approximately 5.9 and 15.4 yen/kWh cheaper than for solar and/or wind‐based pathways. However, limitations of scaling up CCS, a limited brown coal supply, long‐term reducing costs of renewables, and the prospect to develop complementary renewable infrastructure make a strong counterargument for investment in solar and wind pathways as an alternative to brown coal and CCS.     

Catalyzing strategic transformation to a low-carbon economy: A CCS roadmap for China

China now faces the three hard truths of thirsting for more oil, relying heavily on coal, and ranking first in global carbon dioxide (CO₂) emissions. Given these truths, two key questions must be addressed to develop a low-carbon economy: how to use coal in a carbon-constrained future? How to increase domestic oil supply to enhance energy security? Carbon Capture and Storage (CCS) may be a technological solution that can deal with today's energy and environmental needs while enabling China to move closer to a low-carbon energy future. This paper has been developed to propose a possible CCS roadmap for China. To develop the roadmap, we first explore major carbon capture opportunities in China and then identify critical CCS-enabling technologies, as well as analyze their current status and future prospects. We find that coal gasification or polygeneration in combination with CCS could be a nearly unbeatable combination for China's low-carbon future. Even without CCS, gasification offers many benefits: once coal is gasified into syngas, it can be used for many different purposes including for alternative fuels production, thereby increasing the domestic oil supply and the flexibility of the energy system.     

Thermal Hydrogen: An emissions free hydrocarbon economy

Envisioned below is an energy system named Thermal Hydrogen developed to enable economy-wide decarbonization. Thermal Hydrogen is an energy system where electric and/or heat energy is used to split water (or CO₂) for the utilization of both byproducts: hydrogen as energy storage and pure oxygen as carbon abatement. Important advantages of chemical energy carriers are long term energy storage and extended range for electric vehicles. These minimize the need for the most capital intensive assets of a fully decarbonized energy economy: low carbon power plants and batteries. The pure oxygen pre-empts the gas separation process of “Carbon Capture and Sequestration” (CCS) and enables hydrocarbons to use simpler, more efficient thermodynamic cycles. Thus, the “externality” of water splitting, pure oxygen, is increasingly competitive hydrocarbons which happen to be emissions free. Methods for engineering economy-wide decarbonization are described below as well as the energy supply, carrier, and distribution options offered by the system.     

Assessment of flexible energy vectors poly-generation based on coal and biomass/solid wastes co-gasification with carbon capture

This paper evaluates biomass and solid wastes co-gasification with coal for energy vectors poly-generation with carbon capture. The evaluated co-gasification cases were evaluated in term of key plant performance indicators for generation of totally or partially decarbonized energy vectors (power, hydrogen, substitute natural gas, liquid fuels by Fischer–Tropsch synthesis). The work streamlines one significant advantage of gasification process, namely the capability to process lower grade fuels on condition of high energy efficiency. Introduction in the evaluated IGCC-based schemes of carbon capture step (based on pre-combustion capture) significantly reduces CO₂ emissions, the carbon capture rate being higher than 90% for decarbonized energy vectors (power and hydrogen) and in the range of 47–60% for partially decarbonized energy vectors (SNG, liquid fuels). Various plant concepts were assessed (e.g. 420–425 MW net power with 0–200 MW_th flexible hydrogen output, 800 MW_th SNG, 700 MW_th liquid fuel, all of them with CCS). The paper evaluates fuel blending for optimizing gasification performance. A detailed techno-economic evaluation for hydrogen and power co-generation with CCS was also presented.     

Evaluation of syngas-based chemical looping applications for hydrogen and power co-generation with CCS

This paper evaluates hydrogen and power co-generation based on coal-gasification fitted with an iron-based chemical looping system for carbon capture and storage (CCS). The paper assess in details the whole hydrogen and power co-production chain based on coal gasification. Investigated plant concepts of syngas-based chemical looping generate about 350–450 MW net electricity with a flexible output of 0–200 MW_th hydrogen (based on lower heating value) with an almost total decarbonisation rate of the coal used.     

Hydrogen and power co-generation based on coal and biomass/solid wastes co-gasification with carbon capture and storage

This paper investigates the potential use of renewable energy sources (various sorts of biomass) and solid wastes (municipal wastes, sewage sludge, meat and bone meal etc.) in a co-gasification process with coal to co-generate hydrogen and electricity with carbon capture and storage (CCS). The paper underlines one of the main advantages of gasification technology, namely the possibility to process lower grade fuels (lower grade coals, renewable energy sources, solid wastes etc.), which are more widely available than the high grade coals normally used in normal power plants, this fact contributing to the improvement of energy security supply. Based on a proposed plant concept that generates 400–500 MW net electricity with a flexible output of 0–200 MW_th hydrogen and a carbon capture rate of at least 90%, the paper develops fuel selection criteria for coal blending with various alternative fuels for optimizing plant performance e.g. oxygen consumption, cold gas efficiency, hydrogen production and overall energy efficiency. The key plant performance indicators were calculated for a number of case studies through process flow simulations (ChemCAD).     

Un-burnable oil: An examination of oil resource utilisation in a decarbonised energy system

This paper examines the volumes of oil that can and cannot be used up to 2035 during the transition to a low-carbon global energy system using the global energy systems model, TIAM-UCL and the ‘Bottom up Economic and Geological Oil field production model’ (BUEGO). Globally in a scenario allowing the widespread adoption of carbon capture and storage (CCS) nearly 500 billion barrels of existing 2P oil reserves must remain unused by 2035. In a scenario where CCS is unavailable this increases to around 600 billion barrels. Besides reserves, arctic oil and light tight oil play only minor roles in a scenario with CCS and essentially no role when CCS is not available. On a global scale, 40% of those resources yet to be found in deepwater regions must remain undeveloped, rising to 55% if CCS cannot be deployed. The widespread development of unconventional oil resources is also shown to be incompatible with a decarbonised energy system even with a total and rapid decarbonisation of energetic inputs. The work thus demonstrates the extent to which current energy policies encouraging the unabated exploration for, and exploitation of, all oil resources are incommensurate with the achievement of a low-carbon energy system.     

中国中长期碳减排战略目标初探(Ⅱ)——中国煤炭消费过程的碳排放及减排措施

中国能源领域排放的二氧化碳主要来自煤炭,因此煤炭消费过程中的碳减排措施尤为重要。煤炭的主要用户是发电部门,基于应对气候变化的需要,煤电行业的低碳途径不得不考虑采用CCS技术。不论是新建燃煤电厂,还是今后在传统电厂改建过程中增设CCS设施已是大势所趋,预计多数仍将采用MEA法脱除烟气中二氧化碳这一成熟技术。由于MEA法技术经济指标不够先进,估计10~20年内必将出现更先进的脱二氧化碳工艺技术。传统的燃煤锅炉增加CCS的经济效益已经逊于IGCC-CCS,预计2020年后IGCC电厂将成为新建煤电厂的首选方案。20年后采用临氢气化炉与燃料电池FC发电相结合、把高温的热能和甲烷的化学能直接转化为电力的IGFC高效燃煤电厂或将成功应用,IGFC综合能量转化效率比IGCC相对高出1/2~3/4,发展前景不可低估。钢铁、水泥和化工等高耗煤工业部门可通过节能和采用CCS技术降低碳排放,其余用煤的工业部门和分散用户则应考虑节能或用天然气等低碳燃料替代,间接起到减排效果。预计2050年燃煤发电和高耗煤工业总计将排放二氧化碳4.6Gt,如果二氧化碳捕集量是2.9Gt,则净排放量为1.7Gt。加上其他难以捕集二氧化碳的工业、部门及民用煤排放二氧化碳1.0Gt,合计二氧化碳净排放量为2.7Gt(情景A)。如果采用更先进的技术和严格的节能减排措施,可减少煤炭消耗0.31Gt标煤,减少二氧化碳排放0.5Gt,使煤源二氧化碳净排放量减少到2.2Gt(情景B)。无论哪种情景,实施CCS的任务都十分艰巨。     

Thermodynamic modeling and assessment of a combined coal gasification and alkaline water electrolysis system for hydrogen production

The performance of a clean energy system that combines the coal gasification and alkaline water electrolyzer concepts to produce hydrogen is evaluated through thermodynamic modeling and simulations. A parametric study is conducted to determine the effect of water ratio in coal slurry, gasifier temperature, effectiveness of carbon dioxide removal, and hydrogen recovery efficiency of the pressure swing adsorption unit on the system hydrogen production. The exergy efficiency and exergy destruction in each system component are also evaluated. The results reveal that the overall energy and exergy efficiencies of this system are ∼58% and ∼55%, respectively. The weight ratio of the hydrogen yielded to the coal fed to this system is ∼0.126. Although this system produces hydrogen from coal, the greenhouse gases emitted from this system are fairly low.     

Oil and natural gas prices and greenhouse gas emission mitigation

The hikes in hydrocarbon prices during the last years have lead to concern about investment choices in the energy system and uncertainty about the costs for mitigation of greenhouse gas emissions. On the one hand, high prices of oil and natural gas increase the use of coal; on the other hand, the cost difference between fossil-based energy and non-carbon energy options decreases. We use the global energy model TIMER to explore the energy system impacts of exogenously forced low, medium and high hydrocarbon price scenarios, with and without climate policy. We find that without climate policy high hydrocarbon prices drive electricity production from natural gas to coal. In the transport sector, high hydrocarbon prices lead to the introduction of alternative fuels, especially biofuels and coal-based hydrogen. This leads to increased emissions of CO₂. With climate policy, high hydrocarbon prices cause a shift in electricity production from a dominant position of natural gas with carbon capture and sequestration (CCS) to coal-with-CCS, nuclear and wind. In the transport sector, the introduction of hydrogen opens up the possibility of CCS, leading to a higher mitigation potential at the same costs. In a more dynamic simulation of carbon price and oil price interaction the effects might be dampened somewhat.     

中国煤炭制氢成本及碳足迹研究

煤炭制氢是我国当前最主要的低成本制氢方式,但制氢过程伴有大量的CO2排放,不符合低碳发展要求,需要和碳捕集与封存(CCS)技术结合.本文评估了结合CCS技术的煤炭制氢碳足迹和成本,发现:煤炭制氢结合CCS技术后,碳足迹由22.66 kgC02当量(eq)/kgH2下降至10.52kgCO2eq/kgH2,同时制氢成本增...     

Coal and energy security for India: Role of carbon dioxide (CO2) capture and storage (CCS)

Coal is the abundant domestic energy resource in India and is projected to remain so in future under a business-as-usual scenario. Using domestic coal mitigates national energy security risks. However coal use exacerbates global climate change. Under a strict climate change regime, coal use is projected to decline in future. However this would increase imports of energy sources like natural gas (NG) and nuclear and consequent energy security risks for India. The paper shows that carbon dioxide (CO₂) capture and storage (CCS) can mitigate CO₂ emissions from coal-based large point source (LPS) clusters and therefore would play a key role in mitigating both energy security risks for India and global climate change risks. This paper estimates future CO₂ emission projections from LPS in India, identifies the potential CO₂ storage types at aggregate level and matches the two into the future using Asia-Pacific Integrated Model (AIM/Local model) with a Geographical Information System (GIS) interface. The paper argues that clustering LPS that are close to potential storage sites could provide reasonable economic opportunities for CCS in future if storage sites of different types are further explored and found to have adequate capacity. The paper also indicates possible LPS locations to utilize CCS opportunities economically in future, especially since India is projected to add over 220,000 MW of thermal power generation capacity by 2030.     

A comparison of electricity and hydrogen production systems with CO2 capture and storage—Part B: Chain analysis of promising CCS options

Promising electricity and hydrogen production chains with CO₂ capture, transport and storage (CCS) and energy carrier transmission, distribution and end-use are analysed to assess (avoided) CO₂ emissions, energy production costs and CO₂ mitigation costs. For electricity chains, the performance is dominated by the impact of CO₂ capture, increasing electricity production costs with 10–40% up to 4.5–6.5 €ct/kWh. CO₂ transport and storage in depleted gas fields or aquifers typically add another 0.1–1 €ct/kWh for transport distances between 0 and 200 km. The impact of CCS on hydrogen costs is small. Production and supply costs range from circa 8 €/GJ for the minimal infrastructure variant in which hydrogen is delivered to CHP units, up to 20 €/GJ for supply to households. Hydrogen costs for the transport sector are between 14 and 16 €/GJ for advanced large-scale coal gasification units and reformers, and over 20 €/GJ for decentralised membrane reformers. Although the CO₂ price required to induce CCS in hydrogen production is low in comparison to most electricity production options, electricity production with CCS generally deserves preference as CO₂ mitigation option. Replacing natural gas or gasoline for hydrogen produced with CCS results in mitigation costs over 100 €/t CO₂, whereas CO₂ in the power sector could be reduced for costs below 60 €/t CO₂ avoided.     

On the outlook for solar thermal hydrogen production in South Africa

Global warming and tightening environmental legislation is putting pressure on divesting from fossil fuel in the energy sector, with the transport sector likely to see the biggest changes. Current alternative energy sources are electric vehicles and hydrogen. Conventional hydrogen production technologies are fossil fuel based, emitting significant amounts of CO₂ into the atmosphere. This paper explores various ways to integrate solar thermal technologies into hydrogen production to generate carbon free hydrogen in South Africa. South Africa's abundant solar resource indicates that the country may become a significant player in the hydrogen market. However, the high capital cost associated with solar thermal energy put solar thermal hydrogen at a price disadvantage against conventional production technologies. Significant market penetration for solar thermal hydrogen is not expected within the next decade, but cost reduction due to improved manufacturing techniques and larger manufacturing volumes might close the gap in the long term.     

Potential importance of hydrogen as a future solution to environmental and transportation problems

Air pollution is a serious public health problem throughout the world, especially in industrialized and developing countries. In industrialized and developing countries, motor vehicle emissions are major contributors to urban air quality. Hydrogen is one of the clean fuel options for reducing motor vehicle emissions. Hydrogen is not an energy source. It is not a primary energy existing freely in nature. Hydrogen is a secondary form of energy that has to be manufactured like electricity. It is an energy carrier. Hydrogen has a strategic importance in the pursuit of a low-emission, environment-benign, cleaner and more sustainable energy system. Combustion product of hydrogen is clean, which consists of water and a little amount of nitrogen oxides. Hydrogen has very special properties as a transportation fuel, including a rapid burning speed, a high effective octane number, and no toxicity or ozone-forming potential. It has much wider limits of flammability in air than methane and gasoline. Hydrogen has become the dominant transport fuel, and is produced centrally from a mixture of clean coal and fossil fuels (with C-sequestration), nuclear power, and large-scale renewables. Large-scale hydrogen production is probable on the longer time scale. In the current and medium term the production options for hydrogen are first based on distributed hydrogen production from electrolysis of water and reforming of natural gas and coal. Each of centralized hydrogen production methods scenarios could produce 40 million tons per year of hydrogen. Hydrogen production using steam reforming of methane is the most economical method among the current commercial processes. In this method, natural gas feedstock costs generally contribute approximately 52–68% to the final hydrogen price for larger plants, and 40% for smaller plants, with remaining expenses composed of capital charges. The hydrogen production cost from natural gas via steam reforming of methane varies from about 1.25 US$/kg for large systems to about 3.50 US$/kg for small systems with a natural gas price of 6 US$/GJ. Hydrogen is cheap by using solar energy or by water electrolysis where electricity is cheap, etc.     

On capital utilization in the hydrogen economy: The quest to minimize idle capacity in renewables-rich energy systems

The hydrogen economy is currently experiencing a surge in attention, partly due to the possibility of absorbing variable renewable energy (VRE) production peaks through electrolysis. A fundamental challenge with this approach is low utilization rates of various parts of the integrated electricity-hydrogen system. To assess the importance of capacity utilization, this paper introduces a novel stylized numerical energy system model incorporating the major elements of electricity and hydrogen generation, transmission and storage, including both “green” hydrogen from electrolysis and “blue” hydrogen from natural gas reforming with CO₂ capture and storage (CCS). Concurrent optimization of all major system elements revealed that balancing VRE with electrolysis involves substantial additional costs beyond reduced electrolyzer capacity factors. Depending on the location of electrolyzers, greater capital expenditures are also required for hydrogen pipelines and storage infrastructure (to handle intermittent hydrogen production) or electricity transmission networks (to transmit VRE peaks to electrolyzers). Blue hydrogen scenarios face similar constraints. High VRE shares impose low utilization rates of CO₂ capture, transport and storage infrastructure for conventional CCS, and of hydrogen transmission and storage infrastructure for a novel process (gas switching reforming) that enables flexible power and hydrogen production. In conclusion, all major system elements must be considered to accurately reflect the costs of using hydrogen to integrate higher VRE shares.