Electricity Mix Research Articles

Comparative life cycle greenhouse gas emissions assessment of battery energy storage technologies for grid applications

With an ever-increasing penetration of renewable energy sources into the power grid, the development and commercialization of large-scale energy storage systems (ESSs) have been enforced. It is imperative to evaluate the environmental sustainability of ESSs in grid applications to achieve sustainable development goals. In the present work, a cradle-to-grave life cycle analysis model, which incorporates the manufacturing, usage, and recycling processes, was developed for prominent electrochemical energy storage technologies, including lithium iron phosphate batteries (LIPBs), nickel cobalt manganese oxide batteries (NCMBs), and vanadium redox flow batteries (VRFBs). A case study was conducted based on per MWh of energy stored. The greenhouse gas (GHG) emissions of LIPBs, NCMBs, and VRFBs under the Chinese electrical grid peak-shaving scenario were determined to be 323, 263, and 425 kg CO2-eq/MWh, respectively. The key components contributing to the GHG emissions were identified. The GHG emissions of different batteries in renewable energy sources (photovoltaic and wind) were evaluated. Moreover, the GHG emissions under the future electricity mixes were predicted according to the carbon peaking and carbon neutrality goals. The GHG emissions of LIPBs, NCMBs, and VRFBs under the Announced Pledges Scenario could be reduced by approximately 23–27% in 2030 and 66–75% in 2050. Moreover, sensitivity analysis was performed, indicating that the GHG emissions were directly linked with the round-trip efficiency. The results could promote the environment, policy, and business model optimization efforts for large-scale energy storage in low-carbon power systems.

A stakeholder-informed modelling study of Greece's energy transition amidst an energy crisis: The role of natural gas and climate ambition

While fossil fuel prices soar during the 2022 global energy crisis, the European Union activates all available fossil-fuel levers and Greece still plans to use natural gas as a transition fuel for delignitisation, with strong concerns over potential exacerbation of energy poverty and hurdles to progress in climate action. This study assesses the trajectory of the Greek electricity mix and its reliance on natural gas under the current policy framework on the one hand, and an ambitious scenario aiming for complete decarbonisation by 2035 on the other. We model these scenarios using an energy system modelling framework, comprising LEAP and OSeMOSYS model implementations for Greece, and use a stakeholder-informed fuzzy cognitive mapping exercise to uncover transition uncertainties. While power generation from natural gas is projected to increase by almost 50% until 2030 under existing policies, the proposed decarbonisation scenario has the potential to achieve complete independence from Russian gas by 2026 while also leading to a cleaner and considerably cheaper power sector. This ‘higher climate ambition’ scenario is found feasible and more robust in case high fossil fuel prices persist post-2022, even if bottlenecks stressed by stakeholders such as community acceptance or technological constraints emerge and potentially constrain the expansion of certain renewable energy technologies. Apart from the added value of stakeholder input in modelling science, as reflected in the impact of barriers Greek stakeholders critically highlighted, our results emphasise that a diversified energy-supply mix alongside bold energy efficiency strategies are key to rapid and feasible decarbonisation in the country.

Cradle-to-Grave Lifecycle Analysis of Greenhouse Gas Emissions of Light-Duty Passenger Vehicles in China: Towards a Carbon-Neutral Future

Vehicle electrification is considered a pathway for on-road transportation decarbonization in China. Different from the conventional gasoline vehicles whose emissions are mainly released from vehicle tailpipes, emissions of battery electric vehicles (BEVs) are from the upstream processes of electricity generation and vehicle manufacturing, thus a comprehensive lifecycle analysis and comparison of BEVs with gasoline vehicles is required to quantify the emission mitigation benefit of vehicle electrification and determine the path to a carbon-neutral future. In the study, we compare the cradle-to-grave (C2G) lifecycle greenhouse gas emissions of gasoline and electric vehicles in China and analyze the greenhouse gas emission reduction of vehicle electrification in different provinces. Results show that under the current technologies, the national average C2G GHG emissions for battery electric vehicles (BEVs) of 100 miles (i.e., 160 km) and 300 miles (i.e., 480 km) all-electric range (AER) are 231 and 279 g CO2eq/km, respectively, 22% and 5% lower than those for gasoline internal combustion engine vehicles (ICEVs). Improving vehicle fuel efficiency by hybridizing gasoline ICEVs can effectively reduce C2G emissions to 212 g CO2eq/km. At the provincial level, C2G GHG emissions of BEVs vary according to the provincial electricity mix. In eight provinces, C2G GHG emissions of BEVs with 300 miles AER (BEV300s) are higher than those of gasoline ICEVs due to the GHG-intensive coal-based electricity mix. In the future scenario, with low carbon fuels (such as high-level bioethanol blending gasoline) and electricity decarbonization, the national average C2G emissions of hybrid electric vehicles (HEVs) and BEV300s can be reduced to 55 and 73 g CO2eq/km, respectively. Further decrease of C2G GHG emissions relies on reducing vehicle-cycle emissions from material processing and vehicle component manufacturing.

Climate Impact Comparison of Electric and Gas‐Powered End‐User Appliances

AbstractNatural gas is considered a bridging technology in the energy transition because it produces fewer carbon emissions than coal, for example. However, when leaks exist, methane is released into the atmosphere, leading to a dramatic increase in the carbon footprint of natural gas, as methane is a much stronger greenhouse gas than carbon dioxide. Therefore, we conducted a detailed study of methane emissions from gas‐powered end‐use appliances and then compared their climate impacts with those of electricity‐powered appliances. We used the Munich Oktoberfest as a case study and then extended the study to 25 major natural gas consuming countries. This showed that electricity has been the more climate‐friendly energy source at Oktoberfest since 2005, due to the extensive use of renewable electricity at the festival and the presence of methane emissions, particularly caused by the incomplete combustion and leakages of natural gas in cooking and heating appliances. By contrast, at the global level, our study shows that natural gas still produces lower carbon emissions for end‐user appliances than electricity in 18 of the 25 countries studied. However, as the share of renewable energy in the electricity mix steadily increases in most countries, the carbon footprint of electricity will be lower than that of natural gas in these countries in the near future. These findings from our comparison of the total carbon emissions of electric and gas‐powered end‐use appliances can help inform the debate on how to effectively address climate change.

Matching of everyday power supply and demand with dynamic pricing: Problem formalisation and conceptual analysis

The energy transition is expected to significantly increase the share of renewable energy sources whose production is intermittent in the electricity mix. Apart from key benefits, this development has the major drawback of generating a mismatch between power supply and demand. The innovative dynamic pricing approach may significantly contribute to mitigating that critical problem by taking advantage of the flexibility offered by the demand side. At its core, this idea consists in providing the consumer with a price signal which is evolving over time, in order to influence its consumption. This novel approach involves a challenging decision-making problem that can be summarised as follows: how to determine a price signal maximising the synchronisation between power supply and demand under the constraints of maintaining the producer/retailer’s profitability and benefiting the final consumer at the same time? As a contribution, this research work presents a detailed formalisation of this particular decision-making problem. Moreover, the paper discusses the diverse algorithmic components necessary to efficiently design a dynamic pricing policy: different forecasting models together with an accurate statistical modelling of the demand response to dynamic prices.

Assessment of the optimum location and hosting capacity of distributed solar PV in the southern interconnected grid (SIG) of Cameroon

ABSTRACT Cameroon’s electricity mix is dominated by hydropower sources despite the huge potentials of other sources like solar. The over-dependence on hydropower has led to frequent load shedding especially in the dry season as a result of low water levels. Interestingly, the government plans to diversify her power mix and provide sustainable energy to Cameroonians. It is in this framework that this study evaluates the integration of solar PV into the Southern Interconnected Grid of Cameroon using dynamic analysis. The ETAP tool was used in developing the model. A power loss assessment was done through successive injection of solar PV into the candidate busbars while monitoring the active power losses in the grid. Then, a transient stability analysis was conducted so as to assess the grid’s response to induced instability after the penetration of large-scale solar PV. The study showed that the use of static performance indices to evaluate the solar PV hosting capacity do not safeguard the grid’s technical robustness. The results indicated an optimum solar PV penetration level of 30% (211.8 MW) at the Ngousso 93 kV busbar. The findings will be useful to system operators and regulators in developing low-carbon pathways in the electricity network in Cameroon.

Life cycle assessment of a lithium-ion battery with a silicon anode for electric vehicles

New lithium-ion battery generations for electric vehicles are constantly being developed. Currently, batteries with silicon and graphite anode enter the market as third-generation batteries, with limited knowledge of their environmental impacts. This life cycle assessment study evaluates the impacts of the entire life cycle of a prototype lithium nickel manganese cobalt oxide (LiNi0.6Mn0.2Co0.2O2) battery with a silicon-rich anode using the ReCiPe 2016 method. This prototype battery is compared to a state-of-the-art graphite-based battery. A sensitivity analysis is carried out, and the uncertainty of the results is quantified using Monte Carlo analysis. The battery emits 265 gCO2eq/kWh delivered over its life cycle (95 % confidence interval = [219;322]). The energy use in the cell manufacturing phase is critical for all environmental impact categories grouped with climate change. The new silicon-based anode does not contribute more than 7 % to the environmental impact categories. The cathode paste production is the main contributor to ozone formation, human non-carcinogenic toxicity, fine particulate matter, terrestrial acidification, mineral resource scarcity and ecotoxicity (terrestrial, freshwater and marine). The results are sensitive to the carbon intensity of the electricity mix used in the manufacturing phase and during charging. Switching to an electricity mix based on renewable energy sources reduces the impact by up to 53 % (for freshwater eutrophication). The impact categories climate change and ozone formation have the lowest coefficient of variation, while water consumption and human carcinogenic toxicity have the highest. Third-generation batteries can be environmentally beneficial, as soon as their cycle life is sufficient: at least 180,000 km.

Influence of Increasing Renewable Power Penetration on the Long-Term Iberian Electricity Market Prices

In recent years, there has been a significant increase in investment in renewable energy sources, leading to the decarbonization of the electricity sector. Accordingly, a key concern is the influence of this process on future electricity market prices, which are expected to decrease with the increasing generation of renewable power. This is important for both current and future investors, as it can affect profitability. To address these concerns, a long-term analysis is proposed here to examine the influence of the future electricity mix on Iberian electricity prices in 2030. In this study, we employed artificial intelligence forecasting models that incorporated the main electricity price-driven components of MIBEL, providing accurate predictions for the real operation of the market. These can be extrapolated into the future to predict electricity prices in a scenario with high renewable power penetration. The results, obtained considering a framework featuring an increase in the penetration of renewables into MIBEL of up to 80% in 2030, showed that electricity prices are expected to decrease by around 50% in 2030 when compared to 2019, and there will be a new pattern of electricity prices throughout the year due to the uneven distribution of renewable electricity. The study’s findings are relevant for ongoing research on the unique challenges of energy markets with high levels of renewable generation.

Impact of household electricity theft and unaffordability on electricity security: A case of Uganda

Renewable energy sources (RES) dominance in Uganda's electricity mix is challenged by affordability and theft. To assess electricity affordability, the study proposed a probabilistic method to quantify the households into different electricity categories for both urban and rural areas. Alternative electricity billing schemes based on Scenarios A to D for the households to enhance legal connection and consumption of electricity were proposed. The study established that the utility registers the highest electricity theft losses in rural households. The monthly utility revenue collected in urban areas was about 2.9 times that collected in rural areas because of the higher number of legally connected households with a monthly consumption of 1.5 times than that of rural households. From the monthly income spendable on electricity, rural and urban households could only afford 25.07 kWh and 38.29 kWh, respectively, which are less than the average household electricity consumption for Uganda. Also, the initial connection fee to the power grid is very high for the households to afford it in a single down payment. Of the proposed alternative billing schemes, Scenario B and Scenario D yield the least monthly utility revenue collected for the urban and rural households, respectively.

Prospective life cycle assessment of a novel building system with improved foam glass incorporating high recycled content

This article presents a prospective life cycle assessment of the novel building system incorporating an improved foam glass with high recycled content, considering alternative shells (clay and concrete bricks) and construction site locations. The improved foam glass (λ = 0.037 W/m K; ρ = 100 kg/m3) outperforms the commercial foam glass in most environmental impact categories. A fully electric production process is only beneficial with a high share of renewable energy sources in the electricity mix. The use of the improved foam glass can lead to a reduction of climate change impacts by 64 % and resource use - fossil by 66 % in the European foam glass market. The novel building system can have good environmental performance even when assuming long-distance distribution. This article advances in proposing future scenario analyses by identifying life cycle hotspots (e.g. energy intensity, cullet availability), including changes in production, suppliers and market demand. A prospective life cycle assessment allows to anticipate critical issues and provide recommendations for improvement.

Environmental assessment of multiple “cleaner electricity mix” scenarios within just energy and circular economy transitions, in Italy and Europe

The current European context, affected by the dramatic conflict between Russia and Ukraine and the related energy and food shortages, is putting a strain on the natural gas availability of the European member states. The latter are forced to new negotiations with other potential energy suppliers, to urgent internal measures to reduce energy demand and, at the same time, to fulfil their commitments to internationally agreed climate targets, where the energy transition is a key strategy. A sustainable energy transition strategy is also essential in circular economy implementation (CE), requiring the replacement of fossil energies with renewable ones. In turn, the energy transition should meet the CE principles to reduce the consumption of natural resources and the contribution to climate change. In this context, this study assesses the environmental impacts of the Italian and EU electricity mixes under different governmental and research scenarios and perspectives, by means of the Life Cycle Assessment approach (Midpoint and Endpoint LCA). Results show that the shift from the BAU electricity mix (year 2021) to the emergency Government plan scenario (2021–2023) replacing 14% of Russian natural gas by means of 42% oil and coal and 58% renewables slightly reduces the contribution to Midpoint LCA impact indicators, including global warming and fossil resource scarcity, while still contributing to particulate matter formation, terrestrial acidification, eco-toxicity and water consumption. The contribution to global warming further decreases in the other modelled scenarios, where natural gas is assumed to decrease from 30% to a high 60% in favour of renewables (Governmental plan 2030 scenario). Other impacts, in particular terrestrial and human toxicity, are instead expected to worsen, calling for much needed improvement of renewable technologies. Further, the Endpoint LCA impact indicators, expressed as DALY (human health damage), lost species potential (biodiversity damage) and increased costs for the extraction of mineral and fossil resources, improve in the Governmental Plan 2030 scenario and other modelled options. LCA shows to be a key method for the energy transition, in order to identify hotspots of modelled electricity scenarios and suggest more environmentally, circular and socially just improvement solutions. The adoption of the concept of CE in energy transition entails the expansion of the boundaries of an LCA to include the end-of-life of renewable technologies (so-called “cradle to cradle” approach) and the assessment of the most successful options to mitigate the environmental and social impacts of energy transition.

Climate change impacts of e-fuels for aviation in Europe under present-day conditions and future policy scenarios

‘E-fuels’ or ‘synthetic fuels’ are hydrocarbon fuels synthesized from hydrogen (H2) and carbon dioxide (CO2), where H2 can be produced via electrolysis of water or steam reforming of natural gas, and CO2 is captured from the combustion of a fossil or biogenic source or directly from the atmosphere. E-fuels are drop-in substitutes for fossil fuels, but their climate change mitigation benefits are largely unclear. This study evaluates the climate change impacts of e-fuels for aviation by combining different sources of CO2 and H2 up to 2050 under two contrasting policy scenarios. The analysis includes different climate metrics and the effects of near-term climate forcers, which are particularly relevant for the aviation sector. Results are produced for European average conditions and for Poland and Norway, two countries with high and low emission intensity from their electricity production mix. E-fuels can either have higher or lower climate change impacts than fossil fuels, depending on multiple factors such as, in order of importance, the electricity mix, the origin of CO2, the technology for H2 production, and the electrolyzer efficiency. The climate benefits are generally higher for e-fuels produced from CO2 of biogenic origin, while e-fuels produced from CO2 from direct air capture or fossil fuel combustion require countries with clean electricity to outperform fossil fuels. Synthetic fuels produced from H2 derived from natural gas have higher impacts than fossil fuels even when coupled with carbon capture and storage, if CO2 is sourced from fossil fuels or the atmosphere. Climate change impacts of e-fuels improve in the future, and they can all achieve considerable climate change mitigation in 2050relative to fossil jet fuel, provided that strict climate policy measures are implemented to decarbonize the electricity sector. Under reduced policy efforts, future climate impacts in 2050 of e-fuels from atmospheric or fossil CO2 are still higher than those of fossil jet fuels with an average European electricity mix. This study shows the conditions to maximize the climate change mitigation benefits of e-fuels, which essentially depend on progressive decarbonization of the electricity sector and on reduced use of CO2 sourced from fossil fuels.

Environmental and economic analysis of renewable heating and cooling technologies coupled with biomethane utilization: A case study in Chongqing

Renewable heating and cooling systems are regarded as appealing technologies to alleviate energy crises and environmental pollution. An integrated life cycle environmental and Comprehensive Life Cycle Cost (CLCC) method has been proposed and applied to assess the environmental and economic performance of five renewable heating and cooling technologies (RCHTs) for the first time, including Ground Coupled Heat Pump (GCHP), Hybrid Ground Coupled Heat Pump (HGCHP), River Source Heat Pump (RSHP), Air Source Heat Pump (ASHP), and Building Cooling Heating and Power fueled by Biomethane (BCHPB) systems. The results showed the BCHPB system exhibited optimum environmental performance in a commercial building, while the comprehensive environmental impact index of RSHP, HGCHP, GCHP, and ASHP systems were decreased by 24%, 21%, 14%, and 4% as compared to the baseline system. The RSHP system had the lowest comprehensive economic cost of 60.1 CNY/m2, followed by HGCHP (63.9 CNY/m2), ASHP (66.4 CNY/m2), BCHPB (80.0 CNY/m2) and GCHP systems (82.8 CNY/m2). When considering the economic costs and environmental impacts, the eco-efficiency of the RSHP system was increased by 36.7%, 65.5%, 88.4%, and 161.5% compared to HGCHP, ASHP, BCHP, and GCHP systems. In addition, biomethane prices and variable electricity mix significantly affect the environment and financial results.

Statistical Downscaling to Improve the Subseasonal Predictions of Energy-Relevant Surface Variables

Abstract Owing to the increasing share of variable renewable energies in the electricity mix, the European energy sector is becoming more weather sensitive. In this regard, skillful subseasonal predictions of essential climate variables can provide considerable socioeconomic benefits to the energy sector. The aim of this study is therefore to improve the European subseasonal predictions of 100-m wind speed and 2-m temperature, which we achieve through statistical downscaling. We employ redundancy analysis (RDA) to estimate spatial patterns of variability from large-scale fields that allow for the best prediction of surface fields. We compare explanatory powers between the patterns obtained using RDA against those derived using principal component analysis (PCA), when used as predictors in multilinear regression models to predict surface fields, and show that the explanatory power of the former is superior to that of the latter. Subsequently, we employ the estimated relationship between RDA patterns and surface fields to produce statistical probabilistic predictions of gridded surface fields using dynamical ensemble predictions of RDA patterns. We finally demonstrate how a simple combination of dynamical and statistical predictions of surface fields significantly improves the accuracy of subseasonal predictions of both variables over a large part of Europe. We attribute the improved accuracy of these combined predictions to improvements in reliability and resolution.

Environmental assessment of silicon kerf recycling and its benefits for applications in solar cells and Li-ion batteries

Silicon and its usage in photovoltaics and advanced Li-ion traction batteries is a key material for the decarbonisation of the energy and mobility sector. To achieve sustainable silicon-based products, an efficient raw material processing is required. However, the production of silicon and its purification is energy- and resource intensive. Further, during the production of photovoltaic cells, about 40% of the silicon used is lost as sawdust, the so-called silicon kerf, which is often not recycled to a high quality. Compared to primary production, silicon recycling requires less electrical energy and no fossil reductants. However, an environmental assessment of the GHG reduction potential of silicon kerf recycling in comparison to primary production of silicon is limited in literature.In this paper, we will provide a comprehensive environmental assessment of silicon kerf recycling located in Sichuan and Xinjiang in China and Germany, since China is the biggest producer of silicon worldwide. For the assessment of the recycling, a detailed process-specific material and energy flow balance based on industry and literature data is used. The results are evaluated with relation to the primary production of metallurgical silicon and a sensitivity analysis of used electricity mix and transport distance is performed. Results show that recycled metallurgical silicon from silicon kerf creates up to 77% lower GHG emissions compared to conventional primary silicon. Further, environmental hotspots are identified and discussed. Based on the findings, recommendations for target-oriented process engineering are given to further reduce the material-related GHG impacts of silicon based products. Finally, the impact of the results is reflected on the market potential of innovative products like photovoltaics and Li-ion batteries.

Circularity of water - good for conscience or the environment? A deeper look into the water footprint of factories.

Water plays an indispensable role in factories and is needed for a diversity of purposes. The circular use of water is an often-found approach nowadays which refers to the multiple internal recycling of water in factories before releasing it back to the environment. The intention behind that is clear and good – but the question is whether this is actually beneficial from an environmental perspective? This paper aims at providing a more detailed look into that important topic while analyzing efforts and benefits of water circularity. A generic life cycle assessment (LCA) model is presented and different industrial related scenarios serve as a base for deriving deeper and transferable insights into environmentally sustainable water management in factories. For the target objective water consumption, the recycling rate is of limited relevance as it only influences water use (withdrawal) but not the decisive evaporation rate. In a similar way, freshwater deprivation impacts resulting from water consumption (evaporation) depend on the location of the factory and the local scarcity – but not on recycling rates. Also for the global warming potential (GWP), the recycling rate is of limited relevance, as waste water treatment (WWT) is the decisive factor here. In cases in which the internal WWT causes more environmental efforts than municipal WWT and in which a relevant share of water is withdrawn from groundwater, an increasing recycling rate can reduce the depletion of groundwater resources – but causes higher carbon emissions. Depending on local scarcity and carbon intensity of electricity mixes, this can be justified but trade-offs need to be considered.

Electric Vehicle Infrastructure – Concepts and Challenges for Greece

Electric Vehicles (EVs) represent a self-evident solution to environmental issues. Particularly in urban areas, the inhabitants must cope with increasing air pollution from industry and traffic. Promoting the electrification of individual transport can be part of the solution not only to slow down climate change but also to improve the quality of life of city dwellers. Athens has one of the highest emission rates in Europe due to traffic. The Greek Government published the National Plan for Energy and Climate in late 2019. A key message of this plan is that by 2030, one in three vehicles sold in Greece should be equipped with an electric drive. Additionally, Renewable Energy Sources (RES) are about to be promoted, which shall lead to a more environmentally friendly electricity mix (29.2 % share of RES in 2020, aiming for 61 % share of RES in 2030). This is necessary for EVs to achieve a reasonably well-to-wheel CO2 and NOx balance, not only a reasonable tank-to-wheel balance. Government subsidies are intended to create incentives to buy an electric vehicle. Including tax benefits, these subsidies can support the purchase of an electric vehicle for up to 10,000 €. Considering the comparatively low purchasing power in Europe and the lacking Charging Infrastructure, this is an ambitious target. Declining prices for EVs and charging facilities also enable countries with lower GDP per capita to electrify their mobility. This paper’s purpose is to examine whether Greece’s above objective of transport electrification is achievable and in addition to highlighting the strategies and methods that must be utilized to electrify Greece’s private transport. Therefore, the methodology followed includes the calculation of the minimum number of Public Charging Points (PCPs) required and subsequent analysis of pioneer countries regarding EV Infrastructure that Greece should be adapt to electrify its private transport appropriately. Concluding this paper's results show, that Greece's objective is achievable.

Life cycle assessment on calcium zincate production methods for rechargeable batteries

The world's energy transition from fossil to renewable energy is unthinkable without further research in energy storage. Decreasing the environmental impacts from the production of energy storage technologies is essential for achieving a green energy transition. Calcium Zincate (CAZN) is used as active material in rechargeable zinc-based batteries (and other products, such as heterogeneous catalysts for biodiesel or antifungal products). They present a low-cost, safer, alternative to Lithium based batteries and are targeted as replacement solutions for lead-acid batteries.We propose a novelty in the synthesis of CAZN, the hydro-micro-mechanical process (HMMS). The residence time of this new route is about 20 times lower than the traditional processes, so its production needs less infrastructure and can deliver quicker at an industrial scale. In addition, laboratory tests indicate that HMMS CAZN has more reaction surface area and the activation of the battery is 1.77 times faster.Using the life cycle assessment (LCA) method, we compare this new process with the current best option, hydro-thermal synthesis (HTS). The cradle-to-gate results per kg of CAZN already indicates that HMMS is an environmentally better alternative for all indicators; especially when considering the normalization of the results with the residence time and the surface area, HMMS delivers better results, with improvements of 97 % in global warming, for instance. With this, we demonstrate that, outside of the cradle-to-gate, variables that make the final products better service units or give more function should be considered as valuable additional information when deciding among alternatives. This also highlights the importance of life cycle thinking when working with chemical processes and substances.In the sensitivity analysis, we developed 7 scenarios related to the energy demand of the processes, and we incorporated the projection in the European electricity mix for 2030 and 2050.

Solar, Wind and Their Hybridization Integration for Multi-Machine Power System Oscillation Controllers Optimization: A Review

Massive growth in global electrical energy demand has necessitated a genuine exploration and integration of solar and wind energy into the electrical power mix. This incorporation goes a long way in improving the cumulative generated power capacity of the power system. However, wind and solar photovoltaic (PV) are intermittent in nature, making the provisioning of a good maximum power tracking (MPPT) scheme necessary. Furthermore, the integration is characterized by synchronization challenges and introduces various modes of power system oscillations as it is converter-driven. This greatly affects the overall stability of the integrated power mix. Consequently, various technological models have been designed to address these challenges ranging from MPPT schemes, phase-lock loop (PLL), virtual synchronous generator (VSG), power system stabilizers (PSS), flexible AC transmission system (FACTS), coordinated control and artificial intelligence (AI). In this work, a multi-machine power system model is reviewed for integration stability studies. Various technical solutions associated with the integration are also reviewed. MPPT, PLL, VSG, PSS, FACTS, coordinated control, and various optimization technique schemes used for damping controller design are discussed.

Carbon Footprint Assessment of Hydrogen and Steel

Hydrogen has the potential to decarbonize a variety of energy-intensive sectors, including steel production. Using the life cycle assessment (LCA) methodology, the state of the art is given for current hydrogen production with a focus on the hydrogen carbon footprint. Beside the state of the art, the outlook on different European scenarios up to the year 2040 is presented. A case study of the transformation of steel production from coal-based towards hydrogen- and electricity-based metallurgy is presented. Direct reduction plants with integrated electric arc furnaces enable steel production, which is almost exclusively based on hydrogen and electricity or rather on electricity alone, if hydrogen stems from electrolysis. Thus, an integrated steel site has a demand of 4.9 kWh of electric energy per kilogram of steel. The carbon footprint of steel considering a European sustainable development scenario concerning the electricity mix is 0.75 kg CO2eq/kg steel in 2040. From a novel perspective, a break-even analysis is given comparing the use of natural gas and hydrogen using different electricity mixes. The results concerning hydrogen production presented in this paper can also be transferred to application fields other than steel.