Carbon Technologies Research Articles

Interfacial solar evaporation driven Cd removal from contaminated sediments

Solar-driven evaporative remediation (SDER) is an emerging low carbon technology suitable for both seawater desalination and wastewater treatment. Herein, we extend the application of the technique to sediment remediation for the first time by fabricating a functional evaporator (AC@HA-C) comprising cotton loaded with activated carbon and hydroxyapatite. This evaporator accelerated the extraction of Cadmium (Cd) from contaminated sediments. After 14 days of SDER, the overall Cd removal efficiency in sediments ranged between 49.2% and 65.7%. Moreover, cultivation of crops in SDER treated sediments showed an average reduction in Cd accumulation in cabbage by 74.1%. Comparing the AC@HA-C evaporator to other similar materials, life cycle assessment (LCA) showed a 94.0% reduction in environmental impacts and an 86.0% reduction in CO2 emissions. These results position AC@HA-C as a low-carbon and sustainable evaporator, offering a more environmentally friendly choice for sediment remediation.

In-situ targeted removal of naphthalene from groundwater by peroxymonosulfate activation using molecularly imprinted activated carbon: Efficacy, mechanism and applicability

Efficient removal of low-concentration refractory polycyclic aromatic hydrocarbons (PAHs) pollutants is crucial for ensuring groundwater safety. In this study, surface molecularly imprinted catalyst (MIP@AC) was developed based on activated carbon (AC) and molecular imprinting technology, and then MIP@AC was introduced into the simulated permeable reaction barrier to evaluate the performance of MIP@AC activated peroxymonosulfate (PMS) in in-situ targeted remediation of naphthalene (NAP) contaminated groundwater. The results showed that the relative adsorption selectivity coefficient and relative degradation selectivity coefficient of the MIP@AC material relative to the non-imprinted material AC was as high as 31.47 and 10.88, respectively; that is, MIP@AC can better resist the interference of competitive pollutants and achieve efficient targeted removal of NAP. Additionally, the reactive oxygen species (ROS) yield was higher in the MIP@AC/PMS system compared to the AC/PMS system. The target pollutant NAP was precisely enriched in the imprinted cavity of the MIP@AC, realizing that ROS production and pollutant degradation occurred simultaneously in the MIP@AC imprinted cavity. Therefore, the spatial confinement effect of the imprinted cavity shortened the mass transfer distance between the ROS and NAP, thereby reducing the loss of ROS due to self-quenching. Besides, Cl- significantly promoted the targeted removal of NAP, while HCO3- had a slight inhibitory effect; humic acid had no effect because of its larger molecular structure, which does not fit into the small imprinted cavities preferred by NAP. Importantly, the MIP@AC/PMS system demonstrated effective anti-complex matrix interference ability and targeted removal performance for NAP under natural groundwater conditions. This study can promote further research on the surface molecularly imprinted catalyst/PMS system as a new strategy for in-situ targeted remediation technology of contaminated groundwater.

Analysis of perfluorinated compounds in sewage sludge and hydrochar by UHPLC LTQ/Orbitrap MS and removal assessment during hydrothermal carbonization treatment

Wastewater treatment plants have been recognized as important sinks for per- and polyfluoroalkyl substances (PFAS) because of their ineffectiveness in removing them reflecting both water and sewage sludge discharge routes. Hydrothermal treatment represents an alternative technology for treating sludge to recover energy and other valuable products. In this study, 15 PFAS were determined in sludge and hydrochar substrates using sonication-solid phase extraction procedure and analyzed using LC-Orbitrap-High Resolution-MS/MS. The method was fully validated, exhibiting very good linearity, recoveries in the range of 48 to 126 %, low detection and quantification limits with expanded uncertainty and precision below 32 % and 21.9 %, respectively. The method was applied to sludge samples from the WWTP of Ioannina city (Greece), as well as to hydrothermally treated samples under various conditions. The most abundant PFAS were PFHxA (0.5–38.3 ng g−1) and PFOS (4.4–22.1 ng g−1). Finally, the hydrothermally treated sludge samples spiked with PFAS presented removal efficiencies for total PFAS of 86.9 %, 91.8 % and 95.7 % at three spiking levels namely 10, 50 and 200 ng g−1, respectively. Results indicated that PFCAs were almost completely removed, except for PFOA, while the concentrations of PFSAs increased in the produced hydrochar with the formation of several intermediates, as detected by HR-LC-MS/MS. The results of this study demonstrate the effect of hydrothermal treatment to the fate of PFAS in sewage sludge and contribute for further studies on design and scale up of hydrothermal carbonization technology as a management option for safer disposal of municipal wastewater sludge.

CO2 adsorption properties of aerogel and application prospects in low-carbon building materials: A review

The applications and researches of the aerogel in the field of building materials and building energy conservation had been widely concerned due to its excellent thermal insulation properties. However, it has not been paid attention that the potential application values for excellent CO2 adsorption properties of aerogel in building materials. The CO2 adsorption properties of aerogel and the research progress on utilizing SiO2 aerogel in building materials had been reviewed. And the application prospect of the technologies that exploit the CO2 adsorption properties of aerogel and the carbonization technology to prepare SiO2 aerogel-based low-carbon building materials was discussed. It was shown that the type, morphology, and pore structure of aerogel significantly affect the resulting carbon adsorption performance. Amino modification was an effective method for improving the carbon adsorption capacity of aerogel. The performance of aerogel-incorporated cement-based composites could be optimized by improving the performance of binder materials, modifying the aerogel, or preparing new aggregates by loading aerogel into porous materials with higher strength. In addition, it was feasible to prepare new green low-carbon building materials by using aerogel as thermal insulating aggregate and carbon adsorption material, industrial solid wastes rich in alkali metal ions as cementitious materials, and carbonation curing technology. The purpose of this review was to promote the application of CO2 adsorption properties of aerogel in building materials, and enhance the development of low-carbon (or zero-carbon, or negative-carbon) building materials. This is of great significance for reducing carbon emissions in the construction sector and promoting the "carbon neutrality" of global.

Numerical assessment and optimization of photovoltaic-based hydrogen-oxygen Co-production energy system: A machine learning and multi-objective strategy

Green hydrogen production technology based on photovoltaic (PV), battery energy storage system (BESS) and proton exchange membrane (PEM) water electrolysis plays a crucial part in the transition process of energy to zero carbon technology. But few studies have focused on achieving all-day continuous hydrogen production, which is the key to large-scale hydrogen utilization. In this study, we developed an off-grid PV-BESS-PEM system for hydrogen and oxygen production. Firstly, the PV, BESS and PEM water electrolysis components were modeled and model validation was performed. Secondly, an energy management strategy (EMS) is proposed to achieve the goal of continuous and stable hydrogen production. Then, a surrogate model between design variables and optimization objectives is established based on machine learning methods, and a multi-objective optimization algorithm is used to drive the optimization process. Finally, a case study of the PV-BESS-PEM system is presented based on solar irradiation data in Lhasa, where there is sufficient solar resources and oxygen demand. The results demonstrate that the EMS can satisfy the purpose of all-day continuous and stable hydrogen production. The number of cells in the electrolyzer and the water temperature have a significant effect on the hydrogen production and the electrolysis efficiency. And the optimal system has increased the hydrogen production by 16.80 % and the electrolysis efficiency of PEM by 12.08 %, respectively. Herein, the methodological framework is expected to provide theoretical guidance for large-scale water electrolysis hydrogen production applications based on solar energy.

Drivers of Carbon Emissions in Kenya: The Perspective of Technology

The empirical studies have portrayed from a different perspective that technology, foreign direct investment (FDI), and economic growth have diverse outcomes on carbon dioxide (CO2) emissions. African economies specifically Kenya are currently threatened with more CO2 emissions for which proper strategies need to be adopted to reduce and mitigate this situation. To address this issue, the Autoregressive Distributed Lag (ARDL) technique was utilized, differentiating between the long-term and short-term effects of drivers of CO2. Granger causality was applied to analyze the causality between the series. The study uses time series data for Kenya from 1990 to 2022. The short-run and long-run results indicate a negative relationship between technology and carbon emissions. Specifically, an increase in technology reduces carbon emissions while an increase in economic growth and FDI inflow increases carbon emissions. The study has identified the negative nexus between technology and carbon emissions in Kenya. This means that technological innovation can increase labour productivity and utilization of resources, thereby reducing carbon emissions. Therefore, Kenya should increase research and utilization of low and efficient carbon technologies to decouple economic growth from environmental pollution. Based on the result, various strategies have been proposed, including using different clean technologies to produce renewable fuels. FDI that complies with environmental regulations, and the use of advanced green and clean technologies can help mitigate the negative impact of technological progress on the environment. Additionally, technological progress, particularly in information and communication technology, will reduce greenhouse gas emissions and improve environmental quality.

Time Scales of the Low-Carbon Transition: A Data-Driven Dynamic Multi-Sector Growth Model

Abstract This paper employs a dynamic multi-sector growth model with changing technology to study the relevance of the price and quantity dimensions involved in the technical substitution of carbon-intensive technology, that is, the low-carbon transition. For the framing of the transition, the stylized market dynamics by Flaschel and Semmler (1987. “Classical and Neoclassical Competitive Adjustment Processes.” The Manchester School 55 (1): 13–37) are used, who propose a cross-dual out-of-equilibrium adjustment process. The major empirical challenge to identify the adjustment speed for quantities and prices is to empirically estimate sector-specific adjustment coefficients. The transition speed is estimated for seven carbon-intensive sectors in six high-income economies (Germany, France, Italy, Netherlands, Japan, and the US) using a mixed-effects varying-slopes model on EU KLEMS data. Directed technical change is enforced by a revenue-neutral, pro-active fiscal policy of a tax–subsidy form, which has the effect to greatly accelerate the phase-out of carbon-intensive technology and the phase-in of green technology. The speed of green substitution that allows decarbonization is then evaluated analytically and computationally along four policy and time dimensions: cost advantage, a percentage tax on carbon-intensive output, a green subsidy rate, and initial investment ratios. Though the tax itself has an impact on the speed of decarbonization, it is significantly improved by green subsidies and green investments. The cost advantage of the green over the carbon technology is shown to have a negligible impact on decarbonization speed by itself. Without ambitious fiscal policy, especially in the form of green investment support, this substitution process appears to be too slow to reach decarbonization in a timely manner.

Future of hydrogen in the U.S. energy sector: MARKAL modeling results

Hydrogen is an attractive energy carrier which could play a role in decarbonizing process heat, power or transport applications. Though the U.S. already produces about 10 million metric tons of H2 (over 1 quadrillion BTUs or 1 % of the U.S. primary energy consumption), production technologies primarily use fossil fuels that release CO2, and the deployment of other, cleaner H2 production technologies is still in the very early stages in the U.S. This study explores (1) the level of current U.S. hydrogen production and demand, (2) the importance of hydrogen to accelerate a net-zero CO2 future, and (3) the challenges that must be overcome to make hydrogen an important part of the U.S. energy system. The study discusses four scenarios and hydrogen production has been shown to increase in the future, but this growth is not enough to establish a hydrogen economy. In this study, the characteristics of hydrogen technologies and their deployments in the long-term future are investigated using energy system model MARKAL. The effects of strong carbon constraints do not cause higher hydrogen demand but show a decrease in comparison to the business-as-usual scenario. Further, according to our modeling results, hydrogen grows only as a fuel for hard-to-decarbonize heavy-duty vehicles and is less competitive than other decarbonization solutions in the U.S. Without improvements in reducing the cost of electrolysis and increasing the performance of near-zero carbon technologies for hydrogen production, hydrogen will remain a niche player in the U.S. energy system in the long-term future. This article provides the reader with a comprehensive understanding of the role of hydrogen in the U.S. energy system, thereby explaining the long-term future projections.

Business and Market Analysis of Hydrothermal Carbonization Process: Roadmap toward Implementation

This study assesses the status of hydrothermal carbonization (HTC) technology and identifies barriers hindering its commercial viability. Conducting a global survey among HTC companies (with a total of 24 surveys sent), the research evaluates the current landscape, challenges, and future prospects of large-scale HTC operations. Furthermore, it presents a detailed global inventory of existing HTC facilities, illustrating geographical distribution and trends in application. Most of the companies are located in Europe, followed by Asia and North America. With substantial participation from HTC companies, exceeding 62% in the survey (15 companies), the study provides a comprehensive overview of diverse companies, their business models, regulatory challenges, and the overall state of HTC technology. The majority of companies in this study, approximately 80%, offer services in the field of waste management. This paper also explores the potential of HTC in transforming waste management practices, carbon sequestration methodologies, and the development of new materials. Employing a thorough SWOT analysis, the paper advocates for a broader adoption of HTC, emphasizing its transformative capacity in fostering sustainable management of urban, industrial, and agricultural residues, promoting circular economy principles, mitigating climate change, and offering a robust foundation for informed decision-making and sustainable development strategies.

Food web structure and trophic diversity for the fishes of four islands in the Pearl River Estuary, China

The Wanshan Archipelago, situated in the Pearl River Estuary, stood as a key fishing ground in China, boasting abundant fishery resources. To investigate variations in trophic niches and food sources among different islands within the Wanshan Archipelago, and to advance research on fish food webs and energy flow in the Pearl River Estuary, this study conducted a survey of fish communities in nearshore islands (Guishan Island, Dongao Island) and offshore islands (Wailingding Island, Wanshan Island) using triple gill nets during the autumn of 2021. The trophic niche characteristics of fishery organisms in these islands were analyzed utilizing carbon and nitrogen stable isotope technology. The results indicated that trophic niche width and biodiversity of fish communities in the nearshore islands surpassed those in the offshore islands, and the food chain length exhibited a trend of Guishan Island (4.04) > Dongao Island (3.98) > Wanshan Island (3.91) > Wailingding Island (3.86). The trophic niche indexes (CR, NR, CD, and SEAc) of fish communities in nearshore islands were higher compared to those on offshore islands, while MNND and SDNND suggested that fish communities in offshore islands were at a lower trophic level. Zooplankton emerged as the primary food source for fishery organisms in the Wanshan Archipelago. Feeding rates on zooplankton were 68.8 % and 70.4 % in Guishan Island and Dongao Island, and 53.7 % and 58.0 % in Wailingding Island and Wanshan Island, respectively. The proportion of benthic organisms fed near offshore islands was higher than nearshore islands. This study speculated that the fish in nearshore islands may shift from zooplankton food chain to benthic food chain. In addition, this study compared the trophic niche differences among the four islands in the Pearl River Estuary, clarified the diversity of feeding sources and trophic structure within fish communities, and revealed significant distinctions in fish food webs between the islands inside and outside the Pearl River Estuary. It will provide new information on the trophic interactions of fish in the Pearl River Estuary, and help to promote the ecological development and sustainable use of fishery resources.

Trade in Low Carbon Technologies: The Role of Climate and Trade Policies

Trade in Low Carbon Technologies: The Role of Climate and Trade Policies

Optimal decarbonisation pathway for mining truck fleets

The fossil fuel powered mining truck fleets can contribute up to 80% of total emissions in open pit mines. This study investigates the optimal decarbonisation pathway for mining truck fleets. Notably, our proposed pathway incorporates power generation, negative carbon technologies, and carbon trading. Technical, financial, and environmental models of decarbonisation technologies are established, capturing regional variations and time dynamic characteristics such as cost trends and carbon capture efficiency. The dynamic natures of characteristics pose challenges for using the cost-effective analyses approach to find the optimal decarbonisation pathway. To address this, we introduce a mixed-integer programming optimisation framework to find the decarbonisation pathway with minimum life cycle costs during the planning period. A case study for the optimal decarbonisation pathway of truck fleets in a South African coal mine is conducted to illustrate the applicability of the proposed model. Results indicate that the optimal decarbonisation pathway is significantly influenced by factors such as land cost, annual budget, and carbon trading prices. The proposed method provides invaluable guidance for transitioning towards a cleaner and more sustainable mining industry.

Addressing the development gap in net-zero energy buildings: A comparative study of China, India, and the United States

In recent years, the urgency to address climate challenges has driven the need to achieve net-zero carbon goals by 2050. The construction industry, as a major contributor to carbon emissions, plays a vital role in achieving this target. While numerous net-zero energy building approaches have been proposed globally, there is limited comparative research between developed and developing countries. This study aims to address this research gap by selecting the top three carbon-emitting countries in the world - China, India, and the United States (US) - as the research subjects. Through a comparison of their net-zero energy building approaches and typical cases, it is evident that there exists a significant disparity between developed and developing nations. Specifically, differences are observed in the following aspects: net-zero building approaches in the United States have an earlier start and involve collaborations between the government and multiple organizations, while China and India started relatively later and rely primarily on government initiatives. China's consideration of applicable building types in net-zero approaches is not inclusive enough, particularly lacking coverage on industrial buildings. It is encouraging to observe that China and India pay more attention to embodied carbon emissions compared, while their decarbonization strategies for embodied carbon emissions are not as comprehensive as those in the United States when it comes to actual building applications. Regarding carbon offset options, the United States and India demonstrate more comprehensive considerations, while China currently lacks consideration for off-site power generation and negative carbon technologies. The United States boasts a larger number of net-zero buildings, most of which have been certified through the country's own net-zero building approaches. In contrast, China and India have fewer certified net-zero buildings, and only a small percentage have been certified using their own methods, especially in China. The technologies employed in zero‑carbon buildings in the United States are more advanced compared to China and India. These findings underline how the disparities in economic levels between developed and developing countries are reflected in net-zero building approaches. Based on these insights, professionals in the field can develop tailored strategies to bridge the gap in net-zero building development between developed and developing nations. This study provides a foundation and recommendations for achieving carbon neutrality in the construction industry for the world's top three economies by 2030.

Fabrication of Soft-Hard Heterostructure Porous Carbon with Enhanced Performance for High Mass-Loading Aqueous Supercapacitors.

With the increasing attention to energy and environmental issues, the high value-added utilization of biomass and pitch to functional carbon materials has become an important topic in science and technology. In this work, the soft-hard heterostructure porous carbon (NRP-HPC) is prepared by bio-template method, in which biomass and pitch are used as hard carbon and soft carbon precursors, respectively. The prepared NRP-HPC-4 shows high specific surface area (2293m2g-1), suitable pore size distribution, good conductivity (0.25Ωcm-1), and strong wettability. The synergistic effect of soft carbon and hard carbon ensures the composite material exhibiting excellent electrochemical performance for high mass loading (12.0mgcm-2) aqueous supercapacitor, i.e., high specific capacitance (304.69Fg-1 at 0.1Ag-1), high area capacitance (3.67Fcm-2 at 0.1Ag-1), high volumetric specific capacitance (202.74Fcm-3 at 0.1Ag-1), low open-circuit voltage attenuation rate (21.04mVh-1), good voltage retention (79.12%), and excellent cyclic stability (92.04% capacitance retention and 100% coulombic efficiency after 20000 cycles). The composite technology of soft carbon and hard carbon not only ensures the prepared porous carbon electrode materials with enhanced electrochemical performance, but also realizes the high value-added coupling utilization of biomass and pitch.

Renewable cycle for CO2 decomposing by liquid metals at ambient conditions

The decomposition of carbon dioxide (CO2) is a potential negative carbon technology, and an effective way to achieve carbon recycling by converting CO2 into high value-added chemicals. However, the CO2 conversion usually requires harsh conditions, complex processes, and high energy consumption, which seriously limit its application and development. Here, we reported a new strategy for direct decomposition and utilization of CO2 under mild conditions based on liquid metals, in which the CO2 was transformed into carbon, corresponding efficiency is approximately 1.125 ml/(g·h). While the oxygen reacted with liquid metals to form Ga2O3. Furthermore, the oxide by-products can be reduced to the liquid metals using the hydrogen at 800 °C for 10.0 h, which generated from water splitting by solar-driven, whereas 34.33% of liquid metals restore their original properties and can be utilized for further recycling. This provided a novel approach to the decomposition and renewable recycling of CO2.

A Hybrid Real-Time Electricity Pricing Strategy with Carbon Capture, Storage and Trading

During the power system low carbonization process, various policies and technologies for low-carbon have been rapidly developed. Real-time demand side management by energy suppliers based on real-time pricing (RTP) has become a reality via smart meter technology. Motivated by this, an RTP mechanism is used to guide users’ demand response, and the carbon trading regulation (CTR) and carbon capture, storage (CCS) technology are used on the supply side. Through these means, we can reduce carbon emissions from the power system and achieve the goal of carbon neutrality. Furthermore, a game model is used to construct the relationship between the energy supplier and users. Since the energy supplier acts first and then the user make their decision, the leader is the energy supplier and the followers are users. Further, to protect the information privacy of them and independently solve the goals of them, a distributed solution approach combining a differential evolutionary (DE) algorithm and Gurobi solver is developed for finding the equilibrium solution. The proposed model’s economic and environmental benefits are verified and the effectiveness of CCS technology and CTR is accessed via the numerical analysis, what means the proposed strategy can serve as a guide for the system’s low-carbon management.

Simulation of emission reduction path under the path of differentiated energy transformation in China's industrial cities: a case study of Shanghai.

The formulation of long-term step-by-step emission reduction plan is an important step for effective scientific emission reduction. This paper takes Shanghai as the research object, constructs PSO-LSTM model on the basis of STIRPAT model, and further constructs three dynamic policy scenarios combined with China's actual situation and makes short-, medium-, and long-term multivariate predictions for them. The study finds that only the improvement of energy consumption structure has a promotion effect on carbon emission reduction, and urbanization, industrial structure, technology level, population, and economic level all have an increasing effect, and secondly, the carbon emission reduction path of Shanghai basically achieves the core objective of steady decrease under the three scenarios. Secondly, under the three scenarios, Shanghai's carbon emission reduction path basically achieves the core objective of steady decline, but the decline in the GU scenario is more significant. It is recommended that Shanghai further adjusts its industrial structure, optimizes its energy consumption structure, promotes technological innovation and progress, and promotes the development of the circular economy model.

Microstructural Evolution of Calcium Sulfoaluminate Cement during the Wet-Carbonation Process

Calcium sulfoaluminate (CSA) cement, as a type of low-carbon cement, can contribute to further reduction in carbon emissions with carbonation technologies. However, the detailed microstructure development of CSA cement during the carbonation process has been rarely analyzed. In this paper, wet carbonation was applied to CSA cement to investigate the microstructure evolution of carbonation products and carbon absorption capacity of CSA cement by means of pH measurement, X-ray diffraction (XRD) measurement, thermogravimetric (TG) measurement, Fourier-transformed infrared spectroscopy (FT-IR) measurement and scanning electron microscope measurement. During the carbonation process, the formed ettringite product and the dicalcium silicate clinker were carbonated immediately to generate calcium carbonate crystals, silica gel and aluminum hydroxide (AH3) gel. With the trend of pH increasing first and notably decreasing later, the coupling interaction between the hydration and carbonation reactions of CSA cement was revealed. From the XRD and TG results, three types of calcium carbonate crystal forms (calcite, vaterite and aragonite) were detected, and the content of calcium carbonate increased with the increase in carbonation time. FT-IR analysis further confirmed the existence of calcium carbonate, silica gel and AH3 gel with their characteristic vibrations. Moreover, the microstructure of carbonation products with different morphologies was observed. The application of wet carbonation to CSA cement provides a more comprehensive insight to the carbonation mechanism of this low-carbon cement.

Research Needs and Pathways to Advance Hydrothermal Carbonization Technology

Hydrothermal carbonization (HTC) is a proven cost-effective and energy-efficient method for waste management and value-added product recovery. There are, however, several issues that require further improvement or research. Identifying the strengths and weaknesses of HTC in comparison to traditional pyrolysis is crucial for scientists to choose between them or use both (complementary) to achieve specific product properties. Additionally, sharing information on diverse modeling approaches and scales is crucial to enhance the robustness and universality of HTC process models. In addition, the study on the applicability of hydrochars on target applications such as soil amendment is crucial to give back nutrients to soils and face the dependence on finite specific feedstocks in this field. Also, proper management of the process by-products, especially process water, must be addressed to improve the carbon and hydric footprint of the process. Reviewing the suitability of HTC to treat specific challenging wastes, whose strength is not related to their calorific value but to their nutrient composition (i.e., manures), is also an appealing topic for HTC research. This paper aims to tackle the above-mentioned issues through an updated review and discussion of research gaps that require further investigation.

Investment Scenarios for Low Carbon Electricity in Europe

In a context of carbon emissions reduction, this article aims at widening the scope of the OECD - Nuclear Energy Agency (NEA) report entitled « The interaction of Nuclear Energy and Renewable: System Effects in Low Carbon Electricity System » (2012) to the European electric supply by studying the conditions of industrial investments in low carbon technologies over the next 30 years. These conditions can be either favorable or not to, on the one hand, the renewable energies and, on the other hand, the nuclear technologies, according to 3 main dynamically quantified drivers: 1. 2. 3. "Technical change", i.e. relative evolutions of efficiency and costs of available technologies (gas, coal, wind…); "Policy", i.e. incentive framework given by European energy policies (nuclear, climate...); "Economic", i.e. structure of electricity markets (level of centralization...). A total of 24 scenarios are developed using an imaginative approach, i.e. assuming different possibilities for the future change in 3 main drivers. Finally we have found: - 2 scenarios of them prove to be the most favorable to renewable energies; - 2 scenarios favorable to both renewable and nuclear, for the interaction of nuclear and renewable in the electricity system is not necessarily favorable to nuclear investment. These scenarios are then discussed in view of the quantitative drivers mentioned above.