Electricity Generation Technologies Research Articles

Microbial nutrient recovery cell as an efficient and sustainable nutrient recovery option in sewage treatment

Globally, nutrient pollution is a serious and challenging concern. Wastewater treatment plants (WWTPs) are designed to prevent the discharge of contaminants resulting from anthropogenic sources to the receiving water bodies. In this study, seasonal nutrient pollution load, and biological nutrient removal efficiency of an anoxic aerobic unit based WWTP were investigated. Seasonal assessment revealed that the average total nitrogen removal efficiency and total phosphorus removal efficiency of the WWTP do not meet the discharge standard of 10 mg/L and 1 mg/L, respectively. Furthermore, the WWTP does not utilize the energy contained in the wastewater. In this regard, dual chamber MFC (D-MFC) has emerged as a promising solution that can not only treat wastewater but can also convert chemical energy present in the wastewater into electrical energy. However, higher N (57 ± 4 mg/L) and P-P (6 ± 0.52 mg/L) concentration in cathodic effluent is a major drawback in D-MFC. Therefore, to solve this issue, D-MFC was transformed into a microbial nutrient recovery cell (MNRC) which demonstrated a final N -N and P-P concentration of nearly 1 mg/L with N -N and P-P recovery up to 74 % and 69 %, respectively in the recovery chamber. Besides, MNRC attained a maximum power density of 307 mW/m3 and a current density of 1614 mA/m3, thus indicating MNRC is an eco-friendly, energy-neutral, and promising technology for electricity generation and recovering nutrients.

Enhancing PV solar panel efficiency through integration with a passive Multi-layered PCMs cooling system: A numerical study

Photovoltaic (PV) solar cells are at the forefront of sustainable electricity generation technologies, yet they exhibit relatively low efficiency. Typically, less than 20 % of the solar energy absorbed is converted into electrical energy, with the remainder converts into heat. This heat increases the PV panel's operating temperature, negatively impacting its efficiency and life expectancy. To mitigate this, a novel approach using multi-layered phase change materials (PCMs) has been examined in this study. The approach involves integrating organic PCMs (OPCMs) with metallic PCMs (MPCMs), enhancing PV panel cooling efficiency by attaching the multi-layer PCM to the panel's rear. This study, employing ANSYS FLUENT software's solidification and melting model, explores the impact of multi PCM layers thickness and total multi layers thickness on PV cell temperature and electrical efficiency. The analysis reveals that a multi-layered PCMs configuration with a thickness ratio of 15:85 between MPCM (CERROLOW-117® alloy) and OPCM (RT44) significantly decreases temperature rise in PV cells, resulting in a temperature drop of 59.6 °C. This improvement boosts PV panel performance by an average of 35.8 % compared to panels lacking cooling systems during peak sun hours under hot climate conditions characterized by ambient temperatures of 40 °C and high solar radiation exceeding 1000 W/m². This suggests that a carefully optimized PCM layering approach could markedly improve PV system efficiency, offering a practical solution to the overheating problem and extending the operational life of PV installations.

Sustainable All-Day Thermoelectric Power Generation From the Hot Sun and Cold Universe.

Energy conversion from the environment into electricity is the most direct and effective electricity source to sustainably power off-grid electronics, once the electricity requirement exceeds the capability of traditional centralized power supply systems. Normally photovoltaic cells have enabled distributed power generation during the day, but do not work at night. Thus, efficient electricity generation technologies for a sustainable all-day power supply with no necessity for energy storage remain a challenge. Herein, an innovative all-day power generation strategy is reported, which self-adaptively integrates the diurnal photothermal and nocturnal radiative cooling processes into the thermoelectric generator (TEG) via the spectrally dynamic modulated coating, to continuously harvest the energy from the hot sun and the cold universe for power generation. Synergistic with the optimized latent heat phase change material, the electricity generation performance of the TEG is dramatically enhanced, with a maximum power density exceeding 1000mWm-2 during the daytime and up to 25mWm-2 during the nighttime, corresponding to an improvement of 123.1% and 249.1%, compared with the conventional strategy. This work maximizes the utilization of ambient energy resources to provide an environmentally friendly and uninterrupted power generation strategy. This opens up new possibilities for sustained power generation both daytime and nighttime.

Low-humidity sensor and biomimetic power supply based on mesoporous silica/polymerizable deep eutectic solvent ionogels

Although technologies related to humidity detection and utilization, such as humidity sensors, atmospheric water harvesting, energy collection, and moisture-enabled electrical generation technologies, have been widely reported, there is still an urgent need for effective monitoring and utilization of humidity in low-humidity places. An ideal low-humidity sensor requires a high response, fast response time and low humidity hysteresis. Soft ion power supplies inspired by electric eels convert the chemical potential energy of ion gradients into electrical energy by utilizing humidity, but their production is challenging. This paper reports a new strategy for developing functionalized ionogels based on mesoporous silica and a polymerizable deep eutectic solvent (SiO2@PDES). Due to their strong hydrophilicity, high ionic conductivity, excellent adhesion, flexibility and mechanical strength, SiO2@PDES ionogels can not only detect low humidity but also generate electric power through a reasonably designed device structure. In the 5–30% RH range, the response of the SiO2@PDES humidity sensor reaches 1600%, with negligible humidity hysteresis (0.8% RH). As a biomimetic soft ion power supply, SiO2@PDES ionogels generate a high open-circuit voltage of ∼600 mV at 33% RH, which expands the environmental adaptability of moisture-enabled electrical generation equipment. In addition, the excellent moisture-enabled electrical generation performance endows portable wearable power supplies with high potential for applications such as charging capacitors and lighting LEDs.

Correction: Das et al. Comparative Life-Cycle Assessment of Electricity-Generation Technologies: West Texas Case Study. Energies 2024, 17, 992

We discovered a minor mistake in our modeling of the lithium component of the Battery Energy Storage Systems (BESS) that was used in this manuscript [...]

Ökologischer Umbau von Wirtschaft und Gesellschaft: Kosten und Nutzen

Abstract This article weighs up the costs and benefits of the expansion of renewable energy technologies for electricity generation in Germany. According to calculations of the German Ministry of Economic Affairs, this expansion has cost electricity consumers almost 300 billion euros since the introduction of the Renewable Energy Sources Act (EEG) in 2000. Moreover, payment obligations of a similar magnitude are already in place for the next two decades. However, with the accelerated expansion of renewables following Russia’s attack on Ukraine, politicians are accepting costs well in excess of this approximately 600 billion. Given the costs already incurred, a cost-benefit analysis is imperative, not least because further costs in the three-digit billion range are not included in the 600 billion figure, such as the costs for grid expansion, which would not be necessary to the same extent without the expansion of renewables. Against this backdrop, strict attention should be paid to cost discipline in the further expansion of renewables by ensuring that the Federal Network Agency only issues technology-neutral rather than technology-specific tenders for the expansion of renewables in future. This means that only the most cost-efficient renewable technologies will be installed. Consequently, there will be budgetary scope for future investments that could boost the growth potential of the German economy more than the expansion of renewable energies. Contrasting with the high costs, the benefits of expanding renewable energies are modest. For example, the share of renewables in primary energy consumption in 2022 was only around 17 %. With such a low share, achieving greenhouse gas neutrality in 2045 with renewables alone appears to be a tremendous challenge.

Investigating the effectiveness of a mobile wind turbine generating electricity from vehicle air movement

This study presents an evaluation of the effectiveness of a portable wind generator designed to harness wind flow generated by moving vehicles for electricity production. With a growing emphasis on renewable energy sources and the need for sustainable power solutions, innovative approaches such as utilizing vehicle-induced wind currents have gained attention. The portable wind generator under examination is engineered to capture airflow from passing vehicles and convert it into electrical energy. Through a combination of field experiments and theoretical analysis, the performance and efficiency of the device were assessed under various environmental and traffic conditions. Factors such as wind speed, direction, and vehicle velocity were considered in the evaluation process. The results indicate promising potential for the portable wind generator as a supplementary power source, particularly in environments with high vehicular traffic. However, challenges such as variability in wind patterns and optimal positioning of the generator remain areas for further investigation and refinement. Overall, this study contributes to the understanding of utilizing unconventional wind resources and provides insights into the practical implementation of mobile wind energy technology for sustainable electricity generation.

Microalgae Film-Derived Water Evaporation-Induced Electricity Generator with Negative Carbon Emission.

Water evaporation-induced electricity generators (WEGs) are regarded as one of the most promising solutions for addressing the increasingly severe environmental pollution and energy crisis. Owing to the potential carbon emission in the preparation process of WEGs, whether WEG represents a clean electricity generation technology is open to question. Here, a brand-new strategy is proposed for manufacturing negative carbon emission WEG (CWEG). In this strategy, the microalgae film is used as the electricity generation interface of WEG, which achieves a stable open-circuit voltage (Voc) of 0.25V and a short-circuit current (Isc) of 3.3µA. Since microalgae can capture carbon dioxide during its growing process, CWEG holds great promise to generate electricity without carbon emissions in the full life cycle compared with other WEGs. To the best of the author's knowledge, this is the first work using microalgae films to fabricate WEG. Therefore, it is believed that this work not only provides a new direction for designing high-efficiency and eco-friendly WEG but also offers an innovative approach to the resource utilization of microalgae.

Rack and Pinion Based Electricity Generation through a Speed Breaker: A Feasibility Study

Electricity is an essential power source for the economic performance of a developing country like Bangladesh. Due to significant system losses, delays in the installation of new plants, low plant efficiency, and lack of incentives for power plant maintenance, the country's energy-producing facilities have been unable to fulfill the present demand. To meet up this enormous demand, a very simple electricity generation technology was designed. The objectives of the study were to design and fabricate a considerable electricity generation system from a speed breaker and finally determine the technical performance of the system. The production plant was set up using a rack and pinion system. The Damper system comprised of a spring that pushed the speed breaker upwards when it was pushed upon by the weight of the vehicle downwards during trafficking of any vehicles over the speed breakers. As a result, the Rack moved downward, transmitting power to the pinion as motion. The production unit was able to produce 4.2 watts, 6.72 watts, and 0.84 watts, respectively, using a motorcycle, a car, and an easy bike. Our fabricated plant has a total power output of 2683 kW. The unit's entire annual cost, including starting costs and total running costs, is projected to be around $269.65. The capital recovery factor and capital consumption were 0.395 and $44.87 respectively. The proposed design will be helpful to reduce the energy crisis problem in Bangladesh because nowadays in our country the number of vehicles is in increasing trend.

Assessing and enhancing the regional sustainability of electricity generation technologies in an energy-importing megaregion in China

Decision-makers are increasingly concerned about the sustainability of power generation technologies to achieve a secure and sustainable electricity supply in the future. This study aims to assess the sustainability of the eight key electricity generation technologies in the energy-importing Yangtze River Delta region of China and further enhance the regional sustainability of the electricity generation mix. We employed the multi-criteria decision-making process to rank the sustainability of the eight electricity generation technologiesfrom the perspective of various decision-makers. First, the results revealed that no technology is absolutely most sustainable. Second, the subjective findings show that hydropower is the most sustainable technology among the assessed ones, followed by nuclear and onshore wind power. Third, policymakers regard fossil fuel energy as more sustainable than investors and experts. Furthermore, local renewable diffusion and substantial electricity imports from renewable-rich areas can enhance the sustainability of the localelectricity system. In addition,an interregional electricity transmission grid with the neighbor Anhui province as the primary backup power supplier can sufficiently enhance the sustainability of the electricity system in the Yangtze River Delta region.

Role of electricity generation technology in the long-term energy sustainability of India

Electricity distribution has become one of the most essential components of our society since the beginning of human civilization, relying on an abundant, reliable, and affordable power supply. Fossil fuels dominate the production of electricity (89.57 %), emitting 68.7 % of greenhouse gases, polluting water and soil, and depleting fossil fuels. Future energy needs are faced with growing demand for coal (772 million tonnes by 2040) and fluctuating fuel prices. The Indian power sector withdraws over 20 billion m3 of water, whereby coal power plants use around 35 % of freshwater. Among the seventeen sustainable development goals, Goal 7 emphasizes meeting the demand for electricity, the availability of clean fuels, and mitigating air pollution. In 2021, about 747 TWh of energy consumption was met by coal, oil (92 TWh), and solar energy (25 TWh). Renewable power would meet the world’s growing energy needs, reduce greenhouse gas emissions, boost the economy, and strengthen the society. Therefore, renewable energy has gained global attention as a sustainable electricity source. For this, a thorough examination of the economic and social implications of electricity generation technologies must be carried out. This study discusses how fossil fuel-based electricity generation affects global health and the environment and helps achieve Goal 7 of the sustainable development goals. All sectors must work together to stop global warming and water war and make electricity available worldwide for integrated development.

Comparative Life-Cycle Assessment of Electricity-Generation Technologies: West Texas Case Study

This comparison of five power plants in West Texas is intended to provide various decision-makers and stakeholders with a holistic picture of the life-cycle environmental impacts associated with these power plants. A key contribution of this analysis is that we assumed all power plants generate the same amount of electricity over a 30-year life, taking a 500 MW combined-cycle gas turbine (CCGT) plant as a benchmark. Also, in two cases, we added battery storage to wind and solar PV facilities to render them nearly as dispatchable as the CCGT. We included the entire supply chain supporting electricity generation, which encompassed raw material sourcing, processing, manufacturing, operations, and product end of life, also called “cradle to grave”. We report on 18 environmental impacts using ReCiPe midpoint (H) impact assessment. The supply chains are global, and impacts are felt differently by host communities across the world. The results can help stakeholders identify hotspots across numerous supply chains with the highest environmental impacts. We discuss some remedial measures and challenges to inform future analysis by the research community.

Avoiding ecosystem and social impacts of hydropower, wind, and solar in Southern Africa’s low-carbon electricity system

The scale at which low-carbon electricity will need to be deployed to meet economic growth, electrification, and climate goals in Africa is unprecedented, yet the potential land use and freshwater impacts from this massive build-out of energy infrastructure is poorly understood. In this study, we characterize low-impact onshore wind, solar photovoltaics, and hydropower potential in Southern Africa and identify the cost-optimal mix of electricity generation technologies under different sets of socio-environmental land use and freshwater constraints and carbon targets. We find substantial wind and solar potential after applying land use protections, but about 40% of planned or proposed hydropower projects face socio-environmental conflicts. Applying land and freshwater protections results in more wind, solar, and battery capacity and less hydropower capacity compared to scenarios without protections. While a carbon target favors hydropower, the amount of cost-competitively selected hydropower is at most 45% of planned or proposed hydropower capacity in any scenario—and is only 25% under socio-environmental protections. Achieving both carbon targets and socio-environmental protections results in system cost increases of 3-6%. In the absence of land and freshwater protections, environmental and social impacts from new hydropower development could be significant.

Mapping Renewable Energy among Antarctic Research Stations

This paper presents an overview of current electricity generation and consumption patterns in the Antarctic. Based on both previously published and newly collected data, the paper describes the current status of renewable-energy use at research stations in the Antarctic. A more detailed view of electricity systems is also presented, demonstrating how different types of resources may be used and combined. The paper will serve as a guide to various renewable-energy generation technologies, highlighting well-established praxis, lessons learned, and potential ideas for improvement. Several renewable electricity generation technologies that have proven effective for use in the Antarctic environment are described. as well as those that are currently in use. Finally, the paper summarizes the major lessons learned to support future projects and close the knowledge gap. The use of renewable-energy sources has the potential to reduce research stations’ greenhouse gas emissions, making research in Antarctica more sustainable. The availability of high-quality energy is crucial for survival and to allow scientists to conduct meaningful research at research stations under harsh Antarctic conditions.

Communication on the potential of applied PV in the European Union: Rooftops, reservoirs, roads (R3)

Photovoltaics (PV) is a cost-competitive and scalable technology for electricity generation that plays a crucial role to accelerate the European energy transition and achieve carbon neutrality. Large-scale installation of rooftop PV, as well as innovative PV applications such as floating PV coupled with hydropower and bifacial PV along roads and railways, offer multi-benefits, not least in reducing competition for land. In this study, we present a geospatial approach to assess the pan-European technical potential of these three applications, using publicly available datasets. The findings reveal that the PV total installed capacity could exceed 1 TWp, which is far larger than the total PV capacity for 2030 in the EU Solar Energy Strategy (720 GWp) and would be a significant contribution to the several TWs needed for the overall transition to net-zero by 2050. The evidence presented is a useful starting point for policy-setting at national and regional level, as well as for research and detailed analyses of location specific solutions.

Evaluating Prospective Energy Services Demand for Residential Solar Photovoltaic (RSPV) Generated Electricity in Lagos State, Nigeria

Rapid urbanisation is pulling demand for energy services and emission of greenhouse gases (GHG) resulting in energy deficit, climate change and global warming. The ongoing energy crisis and degenerating climate condition demands urgent transformation of the energy system to renewable based from nonrenewable (fossil) based. To meet the growing demand for energy services and simultaneously mitigate the environmental impact of the energy sector, an accurate estimation of the demand for renewable generated electricity is vital to guide the policy makers in planning adequately for the adoption of renewable fuelled electricity generation technology in urban areas. This study evaluated the electricity demand for residential solar photovoltaic (RSPV) technology by potential household adopters of the technology in the metropolitan area of Lagos state, Nigeria. The study adopted quantitative research design with structured questionnaire to solicit information from the respondents. Three hundred and twenty-six (326) responses from the potential adopters were analysed with model for analysis of demand for energy (MADE II) and Pareto tool. The results show that the energy intensity for refrigeration services is 1.06 kWh/hh/day, entertainment services is 0.84 kWh/hh/day, computing services is 0.97 kWh/hh/day, space cooling services is 7.59 kWh/hh/day, ventilation services is 9.05 kWh/hh/day, lighting services is kWh/hh/day, cooking services 2.77 kWh/hh/day, process heating services is 6.43 kWh/hh/day and water pumping is 1.89 kWh/hh/day. The study concluded that the household energy services demand for electricity is 24.43 kWh/hh/day by the potential RSPV technology adopters and the total demand from the solar module panel of 31.59 kWh/hh/day with prospect for improvement on the energy intensity at the same output of energy services. Furtherance to this, the study recommends government intervention with formulation and implementation of dedicated policies on household appliances efficiency standard and also introduce financial schemes to support the replacement of inefficient household appliances with highly efficient ones. Further studies could include other non-common energy services that were not considered in this study. The study could also be conducted in other regions of Nigeria and also investigate the economic feasibility and behavioural acceptability of RSPV technology for effective planning of the national energy system transformation.

Effect of investment cost on technology preference in a flexible, low-carbon Finnish power system

This paper investigates the effects of varying investment costs in a cost-optimal portfolio of electricity-generating technologies to achieve a low-carbon power system to help mitigate climate emissions in Finland. Several different cost scenarios for nuclear, solar, wind, and battery technologies are constructed, considering both single- and multi-stage investment-strategy pathways, with sector coupling of the power system to the heating sector and hydrogen production. Potential new nuclear investments are assumed small modular reactors capable of flexible operation, and optional additional flexibility measures from heating and hydrogen sectors are considered. The scenarios are simulated with hourly resolution using GenX, an openly available capacity expansion optimization tool. Across a wide range of assumed investment costs, the results demonstrate a clear role for flexible nuclear power as a provider of both a solid base generation and flexibility to enhance integration of intermittent wind to the system. Despite optimistic cost assumptions for solar and batteries, their role is observed to remain marginal in the Finnish setting, likely due to large seasonal variation in the local solar availability.

Performance evaluation of a novel photo-thermal-electric hybrid system

Solar thermal power systems are promising electricity generation technology; however, their thermal efficiency is low due to the installed tilt angles and heat losses of solar collectors. Herein, a novel photo-thermal-electric hybrid system that integrates a tilt angle-independent and efficient evacuated U-tube solar collector with a thermally regenerative electrochemical cycle is theoretically conceptualized to evaluate its effectiveness. By developing a mathematical model, analytical expressions for performance indicators as well as the conditions delivering electricity of the hybrid system are deduced. Regardless of tilt angle, calculations indicate that the power density, energy efficiency and exergy efficiency can reach 82.99 W m−2, 8.30 % and 7.61 %, respectively. The hybrid system is less efficient than common silicon photovoltaic cells but is more efficient than some photovoltaic/thermal systems. Exhaustive parametric studies reveal that decreasing thermally regenerative electrochemical cycle internal resistance, ambient temperature or liquid flow rate in evacuated U-tube solar collector and increasing temperature coefficient or evacuated U-tube solar collector inlet temperature can enhance the hybrid system performance. Gradient-based local sensitivity analyses identify that the internal resistance and temperature coefficient of the electrochemical cycle are, respectively, the most and least sensitive variables. A practical case study predicts the hybrid system performance under local weather conditions.

Performance prediction and regulation of a tubular solid oxide fuel cell and hydrophilic modified tubular still hybrid system for electricity and freshwater cogeneration

Tubular solid oxide fuel cells (TSOFCs) are a promising technology for electricity generation; however, they also generate high-temperature waste heat, leading to reduced efficiency and energy wastage. To address this challenge and unlock the full potential, a novel geometry-matching hybrid system incorporating methane reforming TSOFC and hydrophilic modified tubular still (HMTS) is proposed and modelled. Considering various irreversible losses, vital performance indicators including power output, energy efficiency and exergy efficiency are firstly derived, through which comprehensive thermodynamic performance features of the TSOFC/HMTS hybrid system are predicted. The proposed system design demonstrates a significant advantage by achieving a maximum output power density that is 99.7 % higher and a corresponding energy efficiency that is 57.3 % higher compared to the standalone TSOFC. Extensive parametric analyses reveal that raising the operating temperature or stream/carbon ratio positively enhances the system's performance. Conversely, increasing electrode tortuosity, electrolyte thickness, wind velocity, or tubular shell diameter negatively degrades the system's performance. In addition, the anode thickness is an optimizable parameter. Local sensitivity analyses identify that the operation temperature and electrode tortuosity are, respectively, the most and least sensitive parameters for performance regulation. The findings make a significant step forward in the field of sustainable and innovative energy solutions.

Environmental Impact of Electricity Generation Technologies: A Comparison between Conventional, Nuclear, and Renewable Technologies

The transformation of the energy sector, based on the development of low-carbon technologies, is essential to achieve climate neutrality. The Life Cycle Assessment (LCA) is a powerful methodology for assessing the environmental impact of energy technologies, which proves to be a useful tool for policy makers. The paper is a review of the main LCA studies of power generation systems performed over the past ten years aiming at comparing the energy technologies to identify those with the lowest impact on the environment, evaluated in terms of gCO2eq/kWh emissions. Screening criteria were established to include only studies of the highest qualitative significance. The authors decided to assign greater weight to emission values reported in more recent studies. For nuclear and renewable energy technologies, most of the emissions are related to the pre-operational phases. Notably, both nuclear and wind technologies, along with other renewable sources throughout their entire life cycle, exhibit significantly lower and less variable emissions compared with conventional gas- and coal-fired technologies.