Net-zero CO2 Research Articles

Editorial: Will the Road to Carbon Neutrality Become Even More Bumpy Than Ever?

The first-ever global stocktake of what has been achieved and what still must be achieved since the 2015 Paris Agreement on climate change shows that we are not on track to meet the target of limiting global temperature increase in 2050 to 1.5°C above preindustrial levels. Although the EU CBAM is still in its transitional stage and the proposal for a substantial revision of the EU ETD is the only file of the ‘Fit for 55’ package that has not yet been adopted, the EU is one of the better performers on the road to the netzero CO2 emissions target for 2050. In 2023, COP28 has set a new ambitious target for greenhouse gas reductions by 2030. However, the geopolitical situation has dramatically changed by the wars in Ukraine and Gaza. The implications for the energy transition from fossil to renewable sources may make the already bumpy road to carbon neutrality even more bumpy than ever.

Carbon footprint of solar based mini-grids in Africa: Drivers and levers for reduction

The massive development of mini-grids (MGs) is seen as a promising alternative to the extension of national grids to achieve universal access to electricity. MGs based on solar photovoltaic are often recognized fully consistent with net-zero CO2 emissions objectives. However, if they have low or even no direct emissions from diesel consumption, they embed indirect carbon emissions due to solar panels and batteries manufacturing. Electrification policies, mainly based on the levelized costs of electricity (LCOE), should likely account for the carbon footprints (CFP) of possible electrification strategies.In this work, we assess the CFP of hybrid MGs (solar, battery, diesel) for rural electrification in Africa. We consider a large number of MG configurations for many locations across the continent. For each location, we identify the lowest CFP and LCOE, and estimate their dependency to meteorological and socio-economic factors.Our results show that: (i) the lowest CFP depends on location and is around 200gCO2/kWh; (ii) it can be higher than the CFP of certain African national grids; (iii) the CFP of hybrid MGs can be lower than the CFP of MGs relying only on solar PV; (iv) for most techno-economic and environmental assumptions, moderate LCOE increases allow significant CFP reductions.

Diverse decarbonization pathways under near cost-optimal futures

Energy system optimization models offer insights into energy and emissions futures through least-cost optimization. However, real-world energy systems often deviate from deterministic scenarios, necessitating rigorous uncertainty exploration in macro-energy system modeling. This study uses modeling techniques to generate diverse near cost-optimal net-zero CO2 pathways for the United States’ energy system. Our findings reveal consistent trends across these pathways, including rapid expansion of solar and wind power generation, substantial petroleum use reductions, near elimination of coal combustion, and increased end-use electrification. We also observe varying deployment levels for natural gas, hydrogen, direct air capture of CO2, and synthetic fuels. Notably, carbon-captured coal and synthetic fuels exhibit high adoption rates but only in select decarbonization pathways. By analyzing technology adoption correlations, we uncover interconnected technologies. These results demonstrate that diverse pathways for decarbonization exist at comparable system-level costs and provide insights into technology portfolios that enable near cost-optimal net-zero CO2 futures.

Solid amine adsorbent with surfactant modification for Direct Air Capture (DAC) under different temperature and humidity conditions

Direct air capture (DAC) technologies have been vigorously pursued to achieve the goal of net-zero CO2 emissions due to the dramatic increase in atmosphere CO2 concentrations and global temperatures. In practical DAC conditions, variations in temperature and humidity can lead to different CO2 adsorption outcomes. Current studies lack comprehensive information on the optimal temperature and humidity conditions for DAC. In this study, a comparison between PMSU-F (impregnating polyethyleneimine (PEI600) on MSU-F support) and PPMSU-F (co-impregnating polyethylene glycol (PEG200) with PEI600 on MSU-F support) under different temperature and relative humidity conditions were conducted. Under dry conditions, the addition of PEG200 effectively enhanced the adsorption capacity, adsorption rate, and amine efficiency and decreased the energy consumption for desorption depending on the comparison of the two absorbents. Under the popular atmospheric temperature ranges (−5 °C–45 °C), an increase in temperature favors CO2 adsorption. Under humid conditions, the presence of PEG200 had a negative effect due to its strong hydrophilicity. By comparing dry and humid conditions, the introduction of moisture generally enhanced overall CO2 adsorption performance, and the adsorption capacity interestingly further increased under low-temperature conditions. The highest CO2 adsorbing capacity of PMSU-F (3.82 mmol/g) and PPMSU-F (3.76 mmol/g) appeared at −5 °C and 75% relative humidity, indicating that low temperature and relatively high relative humidity were more favorable for DAC, which is possibly attributed to the thermodynamic control under low temperatures with moisture. The results indicate that the adsorbents chosen in this study are promising for DAC under low temperatures and relatively high humidity conditions. The performances of modified DAC adsorbents, e.g., adsorption capacity, stability, antioxidant property for industrial-grade DAC system should be evaluated in the next work.

Perceptions of carbon dioxide emission reductions and future warming among climate experts

The Intergovernmental Panel on Climate Change (IPCC) employs emission scenarios to explore a range of future climate outcomes but refrains from assigning probabilities to individual scenarios. However, IPCC authors have their own views on the likelihood of different climate outcomes, which are valuable to understand because authors possess both expert insight and considerable influence. Here we report the results of a survey of 211 IPCC authors about the likelihood of four key climate outcomes. We found that most authors are skeptical that warming will be limited to the Paris targets of well below 2 °C, but are more optimistic that net zero CO2 emissions will be reached during the second half of this century. When asked about the beliefs of their peers, author responses showed strong correlations between personal and peer beliefs, suggesting that participants with extreme beliefs perceive their own estimates as closer to the community average than they actually are.

Carbon management technology pathways for reaching a U.S. Economy-Wide net-Zero emissions goal

The Carbon Management Study Group of the 37th Energy Modeling Forum (EMF 37) designed seven scenarios to explore the role of three potentially key technology suites – point source carbon dioxide capture and storage (PSCCS), direct air capture of carbon dioxide (DACCS), and hydrogen systems (H2) – in shaping the broader technology pathways to reaching net-zero carbon dioxide (CO2) emissions in United States by 2050. Each scenario was run by up to 13 models participating in the EMF 37 study. Results show that carbon dioxide removal technologies were consistently a major part of successful pathways to net-zero U.S. CO2 emissions in 2050. Achieving this net-zero CO2 goal without any form of carbon dioxide capture and storage was found to be impossible for most models; some models also found it impossible to reach net-zero without DACCS. The marginal cost of achieving net-zero CO2 emissions in 2050 was between two and 10 times higher without PSCCS and/or DACCS available. The carbon price at which DACCS was deployed as a backstop technology depended upon the assumed cost at which DACCS was available at scale. Carbon prices were between $250 and $500 per ton CO2 when DACCS deployed as a backstop. The average CO2 capture rate across all models in 2050 in the central net-zero scenario was 1.3 GtCO2/year, which implies a substantial upscaling of capacity to move and store CO2. Hydrogen sensitivity scenarios showed that H2 typically constituted a relatively small share of the overall U.S. energy system; however, H2 deployed in applications that are considered hard to decarbonize, facilitating transition towards net-zero emissions.

The role of electrification and the power sector in U.S. carbon neutrality

The United States has pledged to achieve net-zero greenhouse gas emissions by 2050. We examine a series of net-zero CO2 scenarios to investigate the impact of advanced electrification of end-use sectors on the dynamics of America's net-zero transition through 2050. Specifically, we use an integrated assessment model, GCAM-USA, to explore how advanced electrification can influence the evolution of the electricity system in pursuit of net-zero. State-level resolution for end-use demand sectors and energy transformation is a key feature of GCAM-USA that allows for elucidation of the variation in end-use electrification across states. All scenarios in this study are designed to be consistent with the modeling protocol for the Energy Modeling Forum Study 37 model inter-comparison project. Our scenarios show the scale of transformation in the power sector with average annual capacity additions reaching 121-143 GW/year and 172-190 GW/year in 2050 net-zero CO2 scenarios and 2045 net-zero CO2 scenarios, respectively, in the 2040s — approximately three to five times the 2021-2023 average. In 2050 net-zero CO2 scenarios, electrification rates in 2050 range from 15-48 % for transportation, 65-83 % for buildings, and 20-38 % for industry. If net-zero CO2 is achieved in 2045, transportation, buildings, and industry are 27-53 %, 78-84 %, and 41-53 % electrified by 2050, respectively. Advanced electrification of end-use sectors can reduce the magnitude of reliance on negative emissions by driving down residual positive emissions by mid-century. Altogether, our results demonstrate that a net-zero transition in the United States will require deep and rapid structural changes to the energy system.

The role of the iron and steel sector in achieving net zero U.S. CO2 emissions by 2050

The U.S. steel sector is a hard-to-abate sector because of its heavy dependence on fossil fuels and its high capital requirements. In 2015, the sector was one of the major carbon emitters, contributing 10 % of the U.S. industrial CO2 emissions. The ability to decarbonize the U.S. iron and steel sector directly affects the ability of the U.S. to achieve economy-wide net zero CO2 by 2050. In this paper, we use the Global Change Analysis Model (GCAM) to analyze different U.S. steel sector decarbonization pathways under varying technology, policy, and demand futures. These pathways provide insights on how various low-carbon steelmaking technologies such as those using carbon capture and storage (CCS), hydrogen, or scrap could help reduce U.S. steel emissions by mid-century. In our primary decarbonization pathway, we find that nearly all of the conventional fossil-based steelmaking capacity is fully integrated with CCS by 2050. However, without CCS availability, almost all of the conventional fossil-based steelmaking is phased-out by 2050 and is replaced by hydrogen-based production. Scrap-based production continues to remain vital across both of these decarbonization pathways. Furthermore, we find that demand reduction could help reduce the required levels of CCS and hydrogen-based production in the decarbonization pathways. Implementation of advanced energy efficiency measures could help substantially reduce the sector's energy usage. Finally, we observe that addressing the embodied carbon transfer associated with steel imports will be crucial for fully decarbonizing the U.S. steel sector.

Pathways for the US food processing sector under economy-wide net zero in a multisector dynamic framework

The food processing sector is a large, energy-consuming and CO2-emitting industrial sector. The sector was estimated to account for 6 % of US industrial CO2 emissions in 2020. The sector uses significant amounts of fossil fuels, biomass, and electricity to perform a range of operations such as baking, drying, and refrigeration. Additionally, the sector is tightly linked to the agriculture and land use sectors. In this analysis, we use the Global Change Analysis Model (GCAM), a coupled, energy-economy-agriculture-land-use-water-climate systems model, to examine the role of the food processing sector in the EMF37 2050 US net-zero CO2 scenario. We explore the implications for technology and fuel choice and go beyond to examine US food consumption, food prices, and land-use change. To better understand the sensitivity of our results to alternative developments, we assess multiple sensitivity scenarios for the US and other world regions, with a focus on varied food processing energy intensity pathways.We find that along the EMF37 US net-zero path, the food processing sector electrifies the majority of its process heat. We also find that the industry phases-down natural gas use and completely phases-out coal. Additionally, we observe a marginal decrease in US food consumption per capita relative to our reference scenario. This primarily occurs due to the increase in consumer food prices resulting from increased demand for purpose-grown biomass crops, which compete with food crops for land resources. Finally, cumulative energy savings of 4.2 EJ are achieved from 2020 to 2050 in a scenario in which the US reduces its food processing intensity to EU-15 levels.

High Entropy Alloys as High Performance Catalysts for Electrolytic Water Splitting

Renewable energy driven electrolytic water splitting is a required technology for low-carbon hydrogen production to achieve the goal of net-zero CO2 emission by 2050. This technology also serves as a necessary energy storage route to resolve the intolerable intermittency and unreliability issues of renewable energies. The prevailing of this hydrogen production technology however is restricted by the high cost of electricity. Consequently, developments of cost–effective highly efficient and stable electrocatalysts to drive the electrolytic water splitting reactions are the key. In terms of catalyst developments, mono-component systems are first explored, followed by multi–component systems, taking advantages of possible positive synergy between constituent components. Recently, a new class of multi-component catalyst systems, entropy-stabilized materials, including alloys, oxides, sulfides, phosphides, etc., emerges and is demonstrated promising performances toward electrocatalysis. In light of the variable and flexible element compositions, entropy-stabilized materials provide infinite and enormous potentials for the design of promising electrocatalysts. The key is to maximize the synergy between constituent components. High entropy alloys (HEA), defined as alloys composed of five or more major metallic elements, have been under intensive and extensive development in past fifteen years for their extraordinary mechanical, magnetic, corrosion, and catalytic properties. Herein, an equi–molar FeCoNiCuMo HEA on nickel foam was developed as a breakthrough catalyst for electrocatalytic water splitting, in terms of both activity and stability, in pH-universal media and in severe industrial operation conditions. Furthermore, a new catalytic phenomenon is discovered. Two different catalytic mechanisms function simultaneously on different constituents of the catalyst, and the synergistic interactions between the two categorical domains leads to catalytic kinetics faster than the theoretical limit set by a single rate-limiting step, Tafel step of the Volmer-Tafel route. A new kinetic model is developed to predict a new theoretical lower limit of Tafel slopes of 15 mV/dec based on a synergistic interaction between the two categorical domains of the high entropy alloy catalyst. This new development proves that the theoretical lower limit of Tafel slope of 30 mV/dec posed for the Volmer-Tafel mechanism functioning on a single component catalyst can be further reduced to 15 mV/dec through synergistic interactions between two categorical domains of a multi-component catalyst. It is demonstrated that high entropy materials, composed of five or more atomically/molecularly well-mixed major components, are intrinsically promising candidates for realization of quantum leaps in catalytic performances of catalysts.

Leveraging Flow-Assisted Electrochemistry Toward Decarbonization of Cement Manufacturing

In an effort to decarbonize the global economy by 50% in 2030 and achieve net-zero carbon emissions by 2050, there is a dire need to electrify industrial processes [1]. Approximately 8% of global carbon emissions comes from cement production [2]. Considering the rising demand for cement due to infrastructure expansion, it is critical to develop new concepts for the decarbonization of cement production. With this goal in mind, our work explores the effectiveness of flow-assisted cement electrolysis as a replacement to conventional fossil fuel based high-temperature kilns in cement manufacturing plants [3].In this study, we employ a scalable 3-channel flow-reactor with acidic anolyte, basic catholyte, and a neutral chemical flush in between to generate calcium hydroxide, Ca(OH)2 [4, 5], which is the key ingredient in cement manufacturing. The central channel is separated from either half cells by a cation exchange and an anion exchange membrane. The electrochemical performance of the proposed cement electrolyzer under a variety of operating conditions is investigated by considering the key variables in reactor design, including flow rate, temperature, catalyst choice and feed concentrations, to shed light into the practical challenges of running a 3-channel flow reactor. Our preliminary study indicates that membranes are possibly responsible for a significant fraction of the limited yields of Ca(OH)2. Specifically, the anion exchange membranes tested are susceptible to degradation in alkaline conditions displaying poor ionic conductance, whereas the cation exchange membranes allow significant water crossover. The findings from this study pave the way in understanding key components for cement electrolysis and other electrochemical systems employing 3-channel flow reactors. References DeAngelo, J., et al., Energy systems in scenarios at net-zero CO2 emissions. Nature Communications, 2021. 12(1): p. 6096. Ellis, L.D., et al., Toward electrochemical synthesis of cement—An electrolyzer-based process for decarbonating CaCO3 while producing useful gas streams. PNAS, 2019. 117(23): p.12584. Rissman, J., et al., Technologies and policies to decarbonize global industry: Review and assessment of mitigation drivers through 2070. Applied Energy, 2020. 266: p. 114848. Perego, A., et al., Electrochemical Flow Reactor for Cement Clinker Production. ECS Meeting s, 2021. MA2021-02(27): p. 840. Olsson, J.A., S.A. Miller, and M.G. Alexander, Near-term pathways for decarbonizing global concrete production.Nature Communications, 2023. 14(1): p. 4574.

Opportunities beyond net-zero CO2 for cost-effective greenhouse gas mitigation in China

Achieving net-zero CO2 emissions is the current main focus of China’s carbon neutrality goal. However, non-CO2 greenhouse gases (GHGs) are more powerful climate forcers, making their emission reduction an opportunity to rapidly mitigate future warming. Here, we evaluate non-CO2 mitigation potentials, costs and climate benefits in the context of China’s carbon neutrality goals. The assessment is conducted by coupling the integrated assessment model GCAM with a climate emulator. The findings indicate that mitigation technologies can largely reduce fluorinated gas emissions from industrial sectors, but long-term non-CO2 reductions of energy sector activities rely heavily on fuel switching. Furthermore, the cumulative costs of deploying non-CO2 mitigation technologies are projected to be less than 10% of the total costs of achieving carbon neutrality from 2020 to 2060. If non-CO2 mitigation measures are included in the overall mitigation portfolio, the benefits of avoided warming would by far outweigh the total mitigation cost increase. Our results thus highlight that incorporating a wider suite of GHGs into climate change mitigation strategies can enhance the cost-effectiveness of mitigation efforts.

Strategic Siting of Direct Air Capture Facilities in the United States

Direct air capture (DAC) systems that capture carbon dioxide (CO2) directly from the atmosphere are garnering considerable attention for their potential role as negative emission technologies in achieving net-zero CO2 emission goals. Common DAC technologies are based either on liquid–solvent (L-DAC) or solid–sorbent (S-DAC) to capture CO2. A comprehensive multi-factor comparative economic analysis of the deployment of L-DAC and S-DAC facilities across various United States (U.S.) cities is presented in this paper. The analysis considers the influence of various factors on the favorability of DAC deployment, including local climatic conditions such as temperature, humidity, and CO2 concentrations; the availability of energy sources to power the DAC system; and costs for the transport and storage of the captured CO2 along with the consideration of the regional market and policy drivers. The deployment analysis in over 70 continental U.S. cities shows that L-DAC and S-DAC complement each other spatially, as their performance and operational costs vary in different climates. L-DAC is more suited to the hot, humid Southeast, while S-DAC is preferrable in the colder, drier Rocky Mountain region. Strategic deployment based on regional conditions and economics is essential for promoting the commercial adoptability of DAC, which is a critical technology to meet the CO2 reduction targets.

Deployment expectations of multi-gigatonne scale carbon removal could have adverse impacts on Asia’s energy-water-land nexus

Existing studies indicate that future global carbon dioxide (CO2) removal (CDR) efforts could largely be concentrated in Asia. However, there is limited understanding of how individual Asian countries and regions will respond to varying and uncertain scales of future CDR concerning their energy-land-water system. We address this gap by modeling various levels of CDR-reliant pathways under climate change ambitions in Asia. We find that high CDR reliance leads to residual fossil fuel and industry emissions of about 8 Gigatonnes CO2yr−1 (GtCO2yr−1) by 2050, compared to less than 1 GtCO2yr−1 under moderate-to-low CDR reliance. Moreover, expectations of multi-gigatonne CDR could delay the achievement of domestic net zero CO2 emissions for several Asian countries and regions, and lead to higher land allocation and fertilizer demand for bioenergy crop cultivation. Here, we show that Asian countries and regions should prioritize emission reduction strategies while capitalizing on the advantages of carbon removal when it is most viable.

Solar energy generation from residential buildings, transition of the energy sector from fossils to carbon-free energy and meeting UN SDG

Purpose This study aims to focus on the transition of Kosovo’s energy generation sector from fossil fuels (94%), to renewable sources. The installation of 10 kW photovoltaic (PV) panels in individual houses will mitigate CO2 emissions from electrical energy generation and contribute meeting the sustainable development goals (SDGs; 7, 11 and 13) set by United Nations General Assembly. This study case is based on the installation of PV panels on the roofs, and where possible on the facades of the private residential buildings in seven, the most populated towns of Kosovo (Prishtina, Prizren, Mitrovica, Peja, Gjakova, Ferizaj and Gjilan). Design/methodology/approach This study used the data, in regard to direct normal irradiation, altitude, coordinates, PV system configurations, specific PV power output and optimum tilt of PV panels specific for the selected locations,retrieved from Global Solar Atlas, which is a web-based-tool, as provided by “Solargis,”a company that provides online and commercial solar data resources, selected by The World Bank and the International Finance Corporation. The second software was RETScreen Expert, which is more sophisticated and allows input of more variables with regard to the proposed 10 kW PV system. With the use of RETScreen Expert software, the financial viability of the project, the equity payback period, and the reduction in greenhouse gas (GHG) emissions compared to the base case were assessed. Based on the gained data, the feasibility and outcome of the study case were assessed in terms of power generation, cost and comparison with the present PV installed capacities in Kosovo. Findings Small-scale solar energy generated from individual buildings can make great impact of country’s policies toward lowering CO2 emission as one most influential greenhouse gas in rising average global temperature, improving air quality in towns by lowering emission of harmful gases and particulate matter (PM). As the study foresees installation of 10 kW of PV in residential houses, the calculated yearly energy generation would be around 15 MWh, which is twice of the average of real consumption of a household in Kosovo. This calculated energy generation from private houses is equal in capacity with generation of present PV parks that are connected on grid as reported from Transmission, System and Market Operator of the Republic of Kosovo. This proves that, if implemented, the study outcome would make Kosovo to meet the goal for a carbon free energy and meeting targets of at least three out of 17 SDG set by UNSC. Originality/value This paper’s model provides a ground for a transition of national energy sector from 90% fossils dependence to renewable energy sources (RES). Despite of some barriers such as cost of initial investment, energy storage, lack of government’s incentives and legislative base for households to become prosumer or at best energy self-sufficient buildings, this solution will make Kosovo harness its unused RES and meet targets of Paris Climate Agreement for net zero CO2 emissions from energy production by 2050 and SDG targets.

Impact of carbon dioxide removal technologies on deep decarbonization: EMF37 MARKAL–NETL modeling results

This paper examines the MARKAL-NETL modeling results for the Energy Modeling Forum study on Deep Decarbonization and High Electrification Scenarios for North America (EMF 37) with a specific focus on carbon dioxide removal (CDR) technologies and opportunities under different scenario guidelines, policies, and technological advancements.The results demonstrate that CDR, such as bioenergy with carbon capture and storage (BECCS), direct air capture (DAC), and afforestation, are key technologies in deep decarbonization scenarios and account for 40–60 % of avoided carbon dioxide (CO2) emissions annually. From 2025 to 2050, cumulative CO2 abatement by CDR technologies will range from 37 to 47 billion tons (GtCO2), or more than 2 GtCO2 annually by 2050. The potential scale of CDR and its impact depends on the advancement and costs of energy supply and demand technologies, end-use sector electrification, and availability and costs of CDR. Results show that the price of carbon is substantially lower when advanced technologies are available, particularly in the EMF 37 carbon management scenarios [1].While BECCS deployment is likely to be constrained for environmental and/or political reasons, the results display relatively large-scale BECCS deployment. The study found that BECCS could make a substantial contribution to emissions reductions after 2035, and, in the medium term, CO2 sequestration by BECCS will depend on CO2 price; BECCS deployment starts at a carbon price of around $70/tCO2. Long-term CO2 sequestration by BECCS increases in all scenarios, reaching the same annual level of ∼890 MtCO2 by 2050 in net-zero CO2 scenarios. According to the modeling results, DAC acts as a true backstop technology at carbon prices of around $600/tCO2.

How much methane removal is required to avoid overshooting 1.5 ∘C?

Methane is the second most important anthropogenic greenhouse gas after carbon dioxide. With an atmospheric lifetime of around a decade, methane mitigation starting immediately has the potential to avoid substantial levels of additional warming by mid-century. In addition to the methane emissions reductions that are necessary to limit warming, we address the question of whether technological methane removal can provide additional benefits by avoiding global mean surface temperatures exceeding 1.5 ∘C above pre-industrial—the high-ambition Paris Agreement climate goal. Using an adaptive emissions methane removal routine in a simple climate model, we successfully limit peak warming to 1.5 ∘C for overshoots of up to around 0.3 ∘C. For substantially higher overshoots, methane removal alone is unable to limit warming to 1.5 ∘C, but in an extreme scenario could limit peak warming by an ensemble median 0.7 ∘C if all atmospheric methane was removed, requiring huge levels of net removal on the order of tens of petagrams cumulatively. The efficacy of methane removal depends on many emergent properties of the climate system, including climate sensitivity, aerosol forcing, and the committed warming after net zero CO2 (zero emissions commitment). To avoid overshooting 1.5 ∘C in the low-overshoot, strong-mitigation SSP1-1.9 scenario, a median cumulative methane removal of 1.2 PgCH4 is required, though this may be much higher if climate sensitivity is high or the zero emissions commitment is positive, and in these cases may require ongoing methane removal long after peak warming in order to stabilise warming below 1.5 ∘C.

Assessment of Economic and Environmental Impacts of using Green Hydrogen Gas for Generating Electricity in the KSA

The energy sector in the Kingdom of Saudi Arabia (KSA) faces serious challenges regarding its current energy mix and energy policies. These challenges are even more complex in the sphere of electricity generation. Where on one side, these challenges are attributed to the fast-growing domestic demand for electricity. While on the other side, KSA depends extensively on traditional fossil fuels for generating electricity and hence facing high rates of carbon dioxide (CO2) emissions. To address these challenges, the Kingdom’s 2030 vision opted for economic diversification and decarbonization by encouraging the transition towards using green hydrogen gas for electricity generation as a clean energy source. This attempt has been associated with measures addressing rationalization of the demand side for electricity. The objective of this paper is to explore the economic and environmental viability of using green hydrogen gas for generating electricity in KSA. Working toward this objective, an economic assessment has been applied to five hypothetical cases or scenarios to identify the most cost-effective (least expensive) to run the turbine generator at net zero CO2 emission. In addition, an assessment of the environmental impact has been applied to the same five hypothetical cases or scenarios to identify the most environmentally friendly i.e., help effectively to reduce or minimize the CO2 emissions. The findings of this assessment reject the economic viability of the transition towards using green hydrogen gas for electricity generation in the KSA, where the calculations of the five cases registered an inverse relation between the NPV and the use of green hydrogen gas in electricity generation. These findings confirm the environmental variability of this transition, where the calculations of the five cases registered a positive relation between decarburization and the use of green hydrogen gas in electricity generation. Based on these findings, the economic ramifications and viability of this transition require a thorough investigation addressing economic and non-economic aspects.

Global warming in a net zero CO2 scenario after 2050 a study with FaIR

Global warming is a severe environmental problem which caused by human activities such as damage to the environmental an overuse of resources. In order to control the global warming under 2C, net zero, especially net zero CO2 has been a goal that must be pursued. The net zero is a goal that all the countries can reduce the emission of greenhouse gases to zero. This article uses FaIR climate model to study the effect of different greenhouse gases on temperature anomaly so that to find the main contributor. The effect of net zero CO2 also be estimated. The model concluded that carbon dioxide from burning fossil fuels is the most important contributor to global warming, and zero emissions of CO2 would greatly help mitigate it. In addition, global warming is an inevitable trend, so while reducing CO2 emissions to mitigate the global warming, adaptation to the long-term global warming can also be combined with mitigation.

Potential role of nuclear power in a carbon-free world

Thermal Power Plants (ThPP), along with transport facilities, are the major sources for industrial emissions of carbon dioxide (CO2) believed to be responsible for the greenhouse effect leading to overheating of the lower atmosphere. In the opinion of many scientists, there is a threshold value of the average atmospheric temperature exceeding, which entails the potential for the development of irreversible processes threatening the existence of humankind. To avoid this danger, governments in nearly 200 countries have chosen voluntarily to reach net-zero CO2 emissions by 2050. Renewable Energy Sources (RES), including wind and solar power plants, have been selected as substitutes for ThPPs. However, energy systems based on RES only need to be multiply redundant in terms of installed capacity due to their efficiency being heavily dependent on daily, seasonal and weather factors, leave alone the scale of the required material resources (metals, polymers, concrete, glass, etc.). The major drawback of such energy systems is, however, the RES common-cause failure, e.g., in the event of a global volcanic eruption, when no energy-security requirement can be met to provide energy for satisfying the most vital needs. A need is fully evident for furnishing such energy system with another power source to be not dependent on the event that has caused the mass RES failure. With the net-zero-carbon requirement taken into account, Nuclear Power (NP) appears to be the best option in this respect. Modern NP does not however fully suits this role due to its inherent drawbacks (limited fuel resources, pending Spent Nuclear Fuel (SNF) and RadioActive Wastes (RAW) handling and nuclear-material nonproliferation issues). A potential solution to these drawbacks is a two-component NP technology in a closed nuclear-fuel cycle currently in the process of development. In Russia, where the greatest progress has been achieved in this field of development, under construction is a pilot and demonstration energy complex with the BREST-OD-300 nuclear unit expected to be started up in 2026–2027. Another promising designs to be developed are Small Modular Reactors (SMRs) / Small Nuclear Power Plants (SNPPs).