Conventional Natural Gas Research Articles

Experimental Assessment on the Coupling Effect of Mixing Length and Methane-Ammonia Blends on Flame Stability and Emissions

Lean premixed combustion mode has become attractive for utilization in industrial gas turbines due to its ability to meet strict emissions regulations without compromising engine efficiency. In this combustion mode, the mixing process is the key player that affect the flame structure and stability, as well as the generated emissions. Many studies have investigated the aspects that influence premixed flames, including the effects of turbulence, combustor geometry, and level of partial premixing, while mostly using conventional natural gas fuel represented by methane. Recently, ammonia, a sustainable energy source, has been considered in gas turbines due to its carbon-free fuel producing no CO2. Utilizing 100% ammonia or a blend of methane and ammonia alters the combustion performance of a premixed flame due to the variation associated with the physical and chemical properties of ammonia. Thus, investigating the coupling between blend ratios and mixing length of methane-ammonia on flame stability and emissions is an essential step toward implementing ammonia in industrial gas turbines. In this study, the influence of various methane-ammonia blends, from 0 (pure methane) to XNH3 = 75%, and mixing lengths on the flame performance were studied. The mixing length was altered by delaying the injection (i.e., partially premixing) of the ammonia while using a fixed injection location for the reference methane-air mixture. This was done by using three fuel ports located at three different heights upstream of the combustion chamber. The results showed that the flame stability is negatively influenced by increasing (decreasing) ammonia fraction (mixing length ratio) and is more sensitive to the ammonia fraction than to the mixing length. At a constant equivalence ratio, the CO and NOx performances improved positively by increasing the ammonia volume fractions (especially at XNH3 = 75% compared to XNH3 = 25% and 50%) and the mixing length.

Wellbore and Reservoir Thermodynamic Appraisal in Acid Gas Injection for EOR Operations

This study provides insights into the experience gained from investigating the thermodynamic behavior of well and reservoir fluids during acid gas injection (AGI) in a hydrocarbon field to enhance oil recovery (EOR) and to reduce greenhouse gas emissions. Unlike conventional water and natural gas injection, AGI involves complicated phase changes and physical property variations of the acid gas and reservoir fluids at various pressure-temperature (P-T) conditions and compositions, and both constitute crucial parts of the EOR chain. A workflow is developed to deal with the reservoir fluid and acid gas thermodynamics, which is a key requirement for a successful design and operation. The workflow focuses firstly on the development of the thermodynamic models (EoS) to simulate the behavior of the reservoir fluids and of the injected acid gas and their integration in the field and in well dynamic models. Subsequently, the workflow proposes the thermodynamic simulation of the fluids’ interaction to determine the Minimum Miscibility Pressure (MMP), yielding the dynamic evolution of the fluids’ miscibility that may appear within the reservoir. Flow assurance in the acid gas transportation lines and in the wellbore is also considered by estimating the hydrate formation conditions.

Conventional Natural Gas Project Investment and Decision Making under Multiple Uncertainties

Similar to many energy projects, the evaluation of investments in natural gas projects is influenced by technical and economic uncertainties. These uncertainties include natural resource characteristics, production, decline laws, prices, taxes, benchmark yield, and so on. In China, conventional natural gas is still the dominant energy source. The investors are mainly large state-owned energy companies. Therefore, it is necessary to include the technical and economic uncertainties, as well as the investment decision and optimization problems of the enterprises in a unified analytical framework. To this end, this paper innovatively constructs such a framework. Using numerical simulations of approaches, the process of investment decision optimization by companies based on technology assessment and price forecasting is visualized in detail. The results suggest that the investment decision of the enterprise needs to consider technical and economic uncertainties in an integrated manner. It also needs to combine the business strategy and social responsibility of the enterprise in order to construct the objective function. With the availability of data, the framework and its algorithms can be used for practical evaluation of investment plans and decision supports for conventional natural gas projects. The framework can also integrate the analytical perspective of the macroeconomic and political environment to bring in a more comprehensive range of uncertainties.

Laminar Burning Velocity, Adiabatic Flame Temperature, and Pollutants of Biogas/Air Mixture at Various CO2 Concentrations and Plasma Assist

ABSTRACT Mixtures of CH4 and CO2, known as biogas, are considered as renewable gas with low heat energy, which makes it extremely difficult to use as fuel in conventional natural gas equipment. To better understand the behavior of biogas mixtures and their properties, numerical results of the impact of carbon dioxide on laminar burning velocity and flame temperature of methane (CH4)–carbon dioxide (CO2)–air combustion were done. One of the most promising methods to enhance combustion is the use of a plasma source to assist unstable flames. For this purpose, experimental results to investigate the effect of microsecond pulsed plasma on non-premixed biogas flames were conducted. In the first section, laminar burning velocities and adiabatic flame temperature have been numerically calculated by one-dimensional steady code using several chemical kinetic mechanisms. Numerical results were compared with several experimental results from the literature. The laminar burning velocity and the adiabatic temperature of biogas/air combustion were calculated with CO2 concentration ranging from 0% to 50% in the mixture. The equivalence ratio was varied from 0.4 to 1.4, the initial pressure was set at 1 bar, and the temperature was set to 300 K. The impact of CO2 addition on the CO and NOx emissions at equivalence ratios from lean to rich (0.4–1.4) was investigated. It was found that increasing CO2 in the biogas lowers NOx and increases CO. In the second section, the effects of microsecond pulsed plasma on non-premixed swirling biogas/air flames were experimentally investigated. The plasma-assisted combustion was carried out in a coaxial burner. It consists of two concentric tubes; the central tube delivers the biogas flow to the injector and the annular tube contains a swirler and supplies the airflow. To create plasma in the stabilization zone of the flame, a rod-ring microsecond plasma configuration was used. OH* chemiluminescence measurements are used to describe the structure and stability of the flame. Results showed that plasma generated by microsecond high-voltage (HV) pulses can improve flame stability. An analysis of the optical emission spectra (OES) showed that plasma generates chemically active species such as excited N2*, CH*, OH* molecules, and H* atoms, leading to improved flame stability. The dependence of their intensities on both the pulse repetition frequency (PRF) and the input electrical voltage was investigated. The gas analysis of the exhaust gas was carried out with and without plasma. The exhaust gas concentration measurements revealed that the rod-ring pulsed plasma reduces CO with a low impact on the NOx level.

Economic Performance Indicators for a Geothermal Aquatic Center in Victoria, Australia

The Gippsland Regional Aquatic Centre (GRAC) opened in the town of Traralgon, Victoria, Australia early in 2021. The GRAC utilizes a geothermal energy heating system as an alternative to conventional natural gas furnaces. We have examined 12 full months of heat production from the geothermal system of the GRAC and compared its economic performance against equivalent heat production by natural gas. The geothermal system—the first of its kind in Victoria—operated at >95% availability over its first year of operation. Our economic assessment indicates that the breakeven price for the geothermal energy is about 35% the equivalent price of natural gas and the payback period for the geothermal system is about five years. The results justify the initial capital outlay by Latrobe City Council and are likely to stimulate further development of geothermal heat systems in the region.

Carbon-neutral hydrogen production from natural gas via electrified steam reforming: Techno-economic-environmental perspective

This study proposes and evaluates a novel carbon-neutral hydrogen (H2) production process from natural gas through electrified steam methane reforming (e-SMR) with renewable electricity. The process model consists of different unit technologies such as reforming, water–gas shift, hydrogen pressure swing adsorption, and CO2 capture, along with heat recovery. Then, we evaluated the techno-economic-environmental performance of the proposed e-SMR process by comparing it with the conventional fired-heating steam methane reforming (f-SMR). By employing an electrically driven reformer using renewable energy, e-SMR outperforms f-SMR with less natural gas consumption, higher energy efficiency of 78.7%, and lower net CO2eq emission of 5.28 kg CO2eq/kg H2 and captured 5.58 kg CO2/kg H2; however, it has a drawback, i.e., higher H2 unit production cost (UPC) of 3.49 $/kg with a capacity of 7.06 ton/day. Sensitivity and uncertainty analyses identified the major cost drivers of UPC, such as the prices of natural gas, renewable electricity, and interest rates, as well as economic risks and uncertainties. The economic viability of e-SMR was determined by investigating multiple plant capacities, natural gas markets, renewable energy prices, and possible future CO2 selling prices. According to the investigation, currently, the US and India show promise for e-SMR, with abundant and affordable natural gas and renewable energy resources, both priced at around 3.49 $/kg of H2, respectively. Furthermore, the global 2030's scenario with 45 $/MWh of renewable electricity, and capture CO2 credit of 35 $/ton is observed at 3.40 $/kg H2, compared with that of 2050 at 2.91 $/kg H2. e-SMR is well adaptable to many countries' energy mix because it is flexible to utilize hybrid primary energy input, conventional natural gas as feedstock, and conventional/renewable energy for utilities.

Comparative life cycle environmental and cost assessments of renewable natural gas production pathways

Renewable natural gas (RNG) is one of the most prominent fuels that help reduce upstream emissions from conventional natural gas networks without significant infrastructure changes. While the current resources for RNG are insufficient, there is a substantial interest in establishing the viability of integrating RNG into the gaseous-fuel industry portfolio. However, holistic studies that support the assessment and selection of the fuel production paths are limited. Therefore, the current study attempts to close that gap by introducing a systematic approach to assess the project viability of RNG investments. Twelve waste-to-RNG configurations were evaluated based on three types of waste feedstock and four biogas upgrade technologies in three selected population centres. Life cycle environmental and life cycle cost assessment tools were employed to determine the ecological footprint and economic performance of RNG production routes. Multi-criteria decision-making was applied using the TOPSIS method under varying stakeholder perspectives to derive suitability indices for RNG investments. Finally, recommendations were provided based on the results obtained for successfully implementing waste-to-RNG supply chain paths. According to study findings, not all RNG production methods guarantee positive returns. The least environmental impacts were assured by the anaerobic digestion of animal manure. However, the lowest returns were obtained via the same route. From a pro-economic and neutral decision perspective, landfill gas-based RNG production achieved higher suitability scores. The proposed framework is flexible and can be customized to suit varying decision priorities. The findings are geared towards supporting utility providers, community developers, and potential investors to foresee the success of planned RNG projects to ensure sustainable gaseous fuel networks.

A review on global warming potential, challenges and opportunities of renewable hydrogen production technologies

This review compares global warming potential of renewable hydrogen production technologies including wind- and solar PV-powered water electrolysis, biomass gasification and biogas reforming based on 64 hydrogen production cases compiled from the literature. Unlike many previous studies, this review discusses the cases from various countries, while selecting the production technologies that have potential of commercialisation. Among the four reviewed technologies, wind electrolysis performed the best in global warming impacts (1.29 kg CO2 eq/kg H2), whereas biogas reforming technology performed the worst (3.61 kg CO2 eq/kg H2). Key factors that contributed to most of the impacts were found to be materials used for construction of wind- and solar- electricity generation system for both wind- and solar PV-powered electrolysis, and energy consumption during gasification processes for biomass gasification, while methane leakage during biogas production had the highest contribution to the impacts of biogas reforming cases. On average, the renewable hydrogen cases demonstrated 68–92% lower global warming potential when compared to conventional coal gasification and natural gas steam methane reforming systems. Increasing demand for renewable hydrogen and possibility of hydrogen being integrated into existing natural gas networks highlight the important role of renewable hydrogen production in the future.

Modeling of Hydrogen Blending on the Leakage and Diffusion of Urban Buried Hydrogen-Enriched Natural Gas Pipeline

With the introduction of various carbon reduction policies around the world, hydrogen energy, as a kind of clean energy with zero carbon emission, has attracted much attention. The safe and economical transportation of hydrogen is of great significance to the development of hydrogen energy industries. Utilizing natural gas pipelines to transport hydrogen is considered to be an efficient and economical way. However, hydrogen has a higher risk of leakage due to its strong diffusion capacity and lower explosive limit than conventional natural gas. Therefore, it is of great significance to study the leakage and diffusion law of hydrogen-enriched natural gas (HENG) pipelines for the safe transportation of hydrogen energy. In this study, the leakage and diffusion characteristics of urban buried HENG pipelines are investigated numerically, and the dangerous degree of leakage is analyzed based on the time and area when the gas concentration reaches the lower explosive limit. The influences of hydrogen blending ratio (HBR), operating pressure, leakage hole size and direction, as well as soil type on the leakage and diffusion law of HENG are analyzed. Results show that the hydrogen mixing is not the key factor in increasing the degree of risk after gas leakage for urban buried HENG pipelines. When the HBR is 5%, 10%, 15% and 20%, the corresponding first dangerous time is 1053, 1041, 1019 and 998 s, respectively. This work is expected to provide a valuable reference for the safe operation and risk prevention of HENG pipelines in the future.

Multi-criteria evaluation and optimization of a new multigeneration cycle based on solid oxide fuel cell and biomass fuel integrated with a thermoelectric generator, gas turbine, and methanation cycle

Recently, due to increasing concerns about the reduction of fossil energies reserves and environmental crises, the development of more efficient and low-emission systems has become necessary. An alternative energy system should be able to improve the efficiency of energy production, have a reasonable investment cost and be environmentally friendly. The current research developed a multi-criteria evaluation method of a new multigeneration cycle (MGC) based on a solid oxide fuel cell (SOFC) and biomass fuel. In the planned MGC, the SOFC is fed by syngas from the biomass gasification process. To reduce environmental hazards, a fraction of the carbon dioxide was recycled for reutilization in the aforementioned process. A gas turbine and a thermoelectric generator (TEG) were employed to produce electrical energy and an absorption chiller was embedded to produce cooling. The output heat of the fuel cell was utilized for heating purposes. A part of the electricity produced was feed into the electrolysis cycle to produce hydrogen. Excess hydrogen was combined with carbon dioxide released from the MGC in a synthesis cycle to reduce pollutant emissions by producing methane. A thermodynamic-conceptual, exergoeconomic and environmental evaluation of the MGC was developed. The optimization based on the genetic algorithm to maximize performance and minimize the cost of the MGC was also developed. The results obtained from the optimization indicate that the proposed MGC can compete with most biomass-driven systems. Besides, the amount of carbon dioxide released can be significantly reduced compared to conventional coal, natural gas and petroleum-driven power plants.

Performance and Emissions Comparison between Biomethane and Natural Gas Fuel in Passenger Vehicles: results of the third testing campaign

This paper shows the results of the third (and last) campaign in the BiomethER project (EU-LIFE). It aimed to achieve two newest bio-methane production plants in the Emilia Romagna region (Italy). This manuscript reports the measurements of emission and performance for the vehicles tested, as widely described in the previous papers. So, three passenger cars are fuelled with conventional natural gas and bio-methane from a BiomethER plant. The emissions and performances on the chassis dynamometer for each vehicle have been measured. Inspecting the combustion chambers of the engines allows for evaluating their wear condition. This campaign confirms the results achieved in the previous two campaigns; there are no appreciable deviations for fuel consumption, greenhouse gas and other pollutant emissions between the two gases. The inspection reveals that biomethane reduces the carbon deposits in combustion chambers compared to natural gas in national infrastructure.

Improving Electricity Generation during the Product Reaction Loop and the Use of Exhaust Gas for Co-Product Production Using Polyethylene Waste and Flue Gas or Wood

More energy-efficient industries could reduce the problems of pollution, global warming, energy security, and fossil fuel depletion, including processing waste into raw materials and more efficient energy cogeneration. This research project considers the novelties of the upgraded electricity cogeneration technique, including one open gas turbine during the high-pressure product reaction loop and a second turbine during the exhaust gas for co-product production with only one compressor. The upgraded electricity cogeneration was carried out in two steps and based on the productive use of otherwise useless polyethylene waste, flue gas, and wood. The first step can simulate the simulation model from the existing product production with well-known technology and process units using the Aspen Plus® simulator. The maximum available electricity cogeneration can previously be determined from the thermodynamics of the products and co-products, and an existing energy unit’s characteristic capacity. In the second step, conventional natural gas can be replaced with waste as the raw materials by using the same simulated model from the first step, including electricity cogeneration using the gas turbines during the high-pressure reaction loop, and the exhaust gas as the co-product with only one compressor. This research on electricity generation is based on processes that include the pressure drop during the product reaction loop. This approach is illustrated using an existing methanol production process, using wastes as sustainable raw materials, including electricity cogeneration during the reaction loop and exhaust gas, generating a possible increase in annual profit of 7.28 MEUR/a.

Improving Efficiency of Electric Energy System and Grid Operating Modes: Review of Optimization Techniques

Continuously growing tariff rates for energy carriers required to generate electrical and thermal energy bring about the need to search for alternatives. Such alternatives are intended for the reduction in the electricity and heat net costs as well as the expenses for the operation and maintenance of system elements and damage from power outages or deteriorated power quality. A way to reduce electricity and heat costs is the introduction of distributed energy resources capable of operating on both conventional (natural gas) and alternative (solar and wind energy, biomass, etc.) fuels. The problem of reducing electricity and, in some cases, heat costs are solved by applying mathematical optimization techniques adapted to a specific element or system of the industry in question. When it comes to power industry facilities, optimization, as a rule, includes reducing active power losses by controlling the system mode or specific power unit parameters; planning generating equipment operating modes; defining the optimal equipment composition; improving the regime and structural reliability of grids; scheduling preventive maintenance of equipment; searching for effective power unit operating modes. Many of the problems listed are solved using direct enumeration techniques; modern technical tools allow quickly solving such local problems with a large number of source data. However, in the case of integrated control over the power system or its individual elements, optimization techniques are used that allow considering a lot of operating limitations and the target function multicriteriality. This paper provides an analytical review of optimization techniques adapted to solving problems of improving the efficiency of the power facility operating modes. The article is made on the basis of the research conducted by the authors in the area of optimization of operating modes for electric energy systems and grids. The authors drew conclusions on the applicability of mathematical optimization methods in the power energy area. While conducting the research, the authors relied on their expertise in the development and introduction of the method to optimize the operation modes of energy supply systems with heterogeneous energy sources.

Methane slip reduction of conventional dual-fuel natural gas diesel engine using direct fuel injection management and alternative combustion modes

Alternative combustion mode and change of spray geometry show potential for methane slip reduction in a dual fuel diesel-natural gas internal combustion engine. Three combustion regimes are simulated; a conventional diesel methane dual-fuel combustion and two modes of reactivity controlled compression ignition (RCCI) with early (EIRCCI) and late (LIRCCI) injections. Methane is injected as the premixed fuel into the port and diesel as direct-injected fuel in all combustion modes. The start of direct fuel injection (SOI) is used as the combustion management tool, swiping from misfiring to knock limits at part loads.By switching combustion mode from conventional (CDF) to LIRCCI and EIRCCI, methane slip is reduced by 12% and 33%, respectively. SOI is used effectively to manage methane slip in any combustion mode, but the effect is more substantial in the EIRCCI mode.Emission results support methane slip trends’ observations. Nitrogen oxides (NOx) emission is increased in CDF by advancing SOI and decreased in both the LIRCCI and EIRCCI modes. Compared to CDF, late and early injection RCCI modes produce 417% and 67% more soot. Also, results show that high levels of methane slip in CDF can be reduced to some extent without any geometry modification by SOI management.Three diesel spray angles (SAs) of 60, 90, 120° are examined. Minimum methane slip is obtained when the SA is towards the squish area, and maximum methane slip is obtained when the SA is towards the piston bowl. Increasing SA from 60 to 90 and 120° results in a 16.4% and 42.5% reduction of methane slip.

Carbon-neutral natural gas in South Korea: Households' perspective obtained through a contingent valuation experiment

The government and city gas companies need information on the price premium that households put on the consumption of carbon neutral natural gas instead of conventional natural gas. The objective of this article is to explore the South Korean households' price premium using the data collected through a contingent valuation survey of 1000 households. Person-to-person interviews with a well-prepared questionnaire and one type of dichotomous choice question to elicit incentive-compatible willingness to pay responses were used. Since 52 % of the total respondents reported zero values, the spike model was adopted and estimated. The price premium for carbon neutral natural gas over conventional natural gas was obtained as KRW 124 per Nm 3 (USD 2.58 per mmBtu), securing statistical significance. This value, which is 20 % of the conventional natural gas price of KRW 625 per Nm 3 (USD 12.93 per mmBtu), is higher than the costs additionally incurred by carbon neutral natural gas (USD 0.75 per mmBtu). This portrays that South Korean households can bear some additional burden in the consumption of carbon neutral natural gas. Therefore, policy makers can consider using carbon neutral natural gas as one of new greenhouse gas reduction measures, and it need to establish institutional preconditions such as monitoring, reporting and verification system.

Review of Unconventional Natural Gas Liquefaction Processes

Liquefied natural gas (LNG) has become an important part in the energy industry on account of its high energy density, low carbon emission, and convenient transportation. In recent years, with the discovery of unconventional natural gas resources, the situation of the world’s natural gas liquefaction plants using conventional natural gas as feedstock is changing. Unlike traditional LNG plants, unconventional natural gas liquefaction processes require special considerations in design and manufacturing. This review summarizes and analyzes the characteristics and differences of several typical unconventional natural gas liquefaction processes compared to traditional natural gas liquefaction processes, including coalbed methane liquefaction, synthetic natural gas liquefaction, LNG-FPSO, and PLNG (pressurized liquefied natural gas). Moreover, a state-of-the-art review of the recent progress on design and optimization of unconventional natural gas liquefaction processes is presented.

N2-selective adsorbents and membranes for natural gas purification

Conventional natural gas confronts the growing supply shortage due to the fewer formation reserves. As a powerful replenishment, the nitrogen-rich unconventional natural gas, mainly including shale gas and coalbed methane, has attracted much attention in recent years and stimulated the efficient separation processes for N2-CH4 system. Benefiting from the boom in materials science, a large number of advanced adsorbents and membranes have been used for N2-CH4 separation. In this paper, the recent advances in the design and fabrication of N2-selective adsorbents and membranes for N2 removal from unconventional natural gas are reviewed. The physicochemical characteristics of N2-selective adsorption and membrane materials are briefly introduced, and the internal commonalities between different materials are analyzed to identify the underlying reasons for the specific performance. Additionally, the challenges and directions for the future development of N2/CH4 separation materials are discussed.

Estimation of water demand of the three major Brazilian shale-gas basins: Implications for water availability

Shale gas exists in abundant quantities around the world and could augment conventional natural gas supplies. However, shale gas exploration through the fracking process is associated with negative connotations and is opposed in many countries because of the perceived environmental impacts including water contamination and competition with other water demands. In this context, the contribution of this work is to analyze the long-term impact of fracking water demand on water availability and possible contamination in Brazil. The objective is to estimate the long-term impacts of shale gas development in Brazil considering the water demand and propose regulations to address water withdrawal and contamination concerns based on best practices from around the world as a way forward. The study demonstrates that competition for water by prospective fracking activities in Brazil in comparison to available water resources and other water demands in associated hydrological basins is insignificant. Furthermore, an analysis of policy and regulations identify policy and regulatory recommendations that may ameliorate public concerns about fracking impact on water by enforcing compliance from exploration and production companies. Following this study, other countries can estimate their shale gas exploration realities to determine the impact of fracking impact on water resources.

A Closer Look at the Environmental Impact of Solar and Wind Energy.

Moving towards a sustainable society implies constant improvement in the way energy is supplied and consumed, with wider implementation of solar and wind energy facilities in stand‐alone or hybrid configurations. The goal of this work is to evaluate the lifecycle performance (construction and operation‐related impact) of large‐scale solar and wind energy systems and to compare it with conventional coal and natural gas fossil fuel plants under similar conditions. Environmental analyses of energy conversion systems today usually neglect the construction‐related environmental impact of fossil fuel plants, because it is significantly smaller than the impact related to the operation of the plant. However, the construction of large‐scale renewable plants implies the use of rare materials, transport‐related emissions, and other environmentally impactful activities. The plants evaluated here are configured and compared for similar emissions and similar power output. It is found that the life‐cycle environmental impact of the renewable plants could, in some specific cases, exceed that of the fossil fuel plants. Understanding the reasons behind this and the possible limitations of the different technologies can help plan for sustainable energy systems in the future. Finally, solutions to minimize the impact of renewable energy are proposed for more environmentally friendly implementation and future research.

Assessment of variable solar- and grid electricity-driven power-to-hydrogen integration with direct iron ore reduction for low-carbon steel making

Power-to-gas (PtG) technologies offer a promising approach for decarbonization of energy-intensive industries, particular the iron and steel (I&S) sector, which depends on specific chemical feedstock and processes that are not currently directly electrifiable. However, PtG implementation faces challenges in the medium term related to the carbon footprint of electricity networks, decoupling process applications from variable renewable energy inputs, and economic feasibility. In this study, the design, energy, emissions, cost, and hourly operation of a power-to-hydrogen (PtH2)-based direct reduction of iron (DRI)-electric arc furnace (EAF) system, are investigated for solar energy-rich conditions in the near- to medium term (2030) with the intent to facilitate the deployment of low-carbon DRI-EAF steel making. A plant hourly operating and sizing methodology is developed based on PtH2 and use of renewable, low-cost solar photovoltaic (PV) electricity and H2 storage to counteract grid emissions and cost. The analysis approach is generically applicable to different solar-rich locations and other variable renewable electricity sources. For base-case system design/operating conditions, the emission intensity of the PtH2-I&S process is found to be abated from 890 to 567 kgCO2/tLS (∼36%), in absence of EAF scrap steel use, relative to the use of grid electricity only with no H2 storage, with a slight reduction in the levelized of cost steel (CLS) at 618 USD/tLS. Relative to conventional natural gas (NG)-DRI-EAF and blast/oxygen furnace (BF-BOF) processes, emission intensity is reduced by ∼43–60% and ∼53–74%, respectively. At off-base case PV and water electrolysis capacities, steel making emission intensity reductions of ∼40% relative to conventional NG DRI-EAF are achievable at normalized PV capacities, α = 3, relative to the plant nominal hourly electricity demand, and normalized electrolysis capacities, β ≥ 1.3, relative to the nominal hourly capacity requirement, while maintaining CLS within less than +25% of NG DRI-EAF. Based on the performance improvement and cost reduction potential for electrolysis and solar PV, the sub-space of normalized PV and electrolysis capacities yielding a ∼40% reduction in emission intensity within the above CLS limit would be significantly enlarged towards lower PV capacities (α ≥ 2) and electrolysis capacities (β ≥ 1.2).