Electricity Producers Research Articles

Converting waste into fuel via integrated thermal and electrochemical routes: An analysis of thermodynamic approach on thermal conversion

Municipal solid waste (MSW) is a common problem as it typically ends up in landfills. MSW could be a potential sustainable energy source with proper technology considering its abundant availability and high energy content. As a part of the solution to the MSW problem, the present research investigated a new integrated gasification process to ensure the complete removal of organic compounds (tar) by splitting char and gas products. The char is directed to the combustor to produce electricity for powering CO2-to-methanol electrolysis, while the gas products are sent to the reforming section to decompose tar into syngas. It is found that char composition is sensitive towards the syngas yield and the gasification temperature. The increase of char combustion from 20% to 50% promotes methanol production via electrolysis but suppresses the overall energy productivity due to energy loss in the power generation and electrolysis. The optimum gasification performance is observed at the air/O2 equivalence ratio of ∼0.3 with the syngas heating value (6.4 and 12.3 MJ/Nm3), H2/CO ratio (1.4 and 1.1) and overall efficiency of 65% and 64% for air and oxygen gasifying agents, respectively. These findings show the potential of MSW to electricity and chemical products via gasification which can increaseeconomic value and optimistically increase the residents’ acceptance.

Electricity retailing and price dispersion

In this paper, we identify price development in electricity contracts evaluated from the expectation that prices for homogeneous goods converge according to the “law of one price”. The results indicate a substantial degree of price dispersion and that prices fail to converge. By estimation of the long-run relationships and their dynamics, the study identifies that dispersion in specific electricity products seem to be strengthened as more firms enter the market, while increased consumer switching has the opposite effect. Thus, the findings identify market imperfections in the electricity retail market and the possible sources behind it. The study builds on well-established theoretical models to rationalize price dispersion in homogeneous product markets an uses an empirical approach through a vector error correction model (VECM) to identify the long-run relationships.

Low-Rank Coal Pyrolysis Polygeneration Technology with Semi-Coke Heat Carrier Based on the Dual-Fluidized Bed to Co-Produce Electricity, Oil and Chemical Products: Process Simulation and Techno-Economic Evaluation

Low-Rank Coal Pyrolysis Polygeneration Technology with Semi-Coke Heat Carrier Based on the Dual-Fluidized Bed to Co-Produce Electricity, Oil and Chemical Products: Process Simulation and Techno-Economic Evaluation

Preparation and characterization of RHA based ceramic membrane for gas leak testing in SOFC seals

Solid Oxide Fuel Cell (SOFC) systems show great potential in future power generation applications. SOFC has many advantages, including high efficiency, low emission, and flexible modular structure. SOFC is an electrochemical device that converts fuel into electricity directly. If hydrogen gas is used, it will produce electricity and waste products in the form of heat and water vapor. The complete SOFC module system consists of a furnace, cell stack, fuel and oxygen. Several parameters that affect SOFC performance are fuel flow rate, furnace temperature, cell material, and collector current. SOFC consists of anode, electrolyte, cathode, and current collector. These parameters have a correlation with each other in building a SOFC system, resulting in a good cell and optimal output voltage. SOFC based on electrolyte material yttria stabilized zirconia (YSZ) operates at working temperatures between 600 to 1,000°C, so all materials used must be able to withstand these temperatures. In the empirical case to separate each function of the components in the fuel cell, a sealant is needed. The sealant function prevents fuel and oxidant leakage in the stack and electrically isolates the cells in the stack. So the other sealant material requirements are to have thermal and chemical compatibility with other cell components, chemically and physically stable at high temperatures and have good mechanical strength. The composition of the material (RHA, CaO, Al2O3, MgO and BaO) with six formulations (F1-F6) which was determined as a gas leak test specimen through a synthesis process using the ball mill method for 12 hours resulted in a grain variation between 3.808 um – 19.631 um. The production of gas leak test specimens was successfully carried out by molding which was designed to be effective using a material weight of 1.5 grams with a 96% PVA binder as much as 20% by weight. The size of the specimen obtained in the form of a membrane with a thickness of 1-1.1mm. The preparation of the test material can be continued in the next gas leak test process.

Biorefinery of galacturonic acid using a biofuel cell as a reactor

A reactor based on an enzymatic biofuel cell (an EBFC reactor) was constructed to simultaneously generate electricity and chemical products from biomass.

Optimal economic planning for the development of waste management system by a superstructural model

In this paper, a model of integrated waste management system was presented that evaluates the possibility of energy supply by the system and offers sustainable plans for expansion and development of the system in the long-time horizon. Initially, the system superstructure was represented, which includes waste-to-energy (WtE) processes with electricity product and waste-to-material (WtM) processes with products of recycled material and compost, and does not include the transportation sector. The mixed and source-segregated municipal solid waste, which is collected from city area, can be considered as feedstock in superstructure. Then, an optimization model of mixed integer nonlinear programming was formulated based on the superstructure. In addition to optimally determining the strategic process and feedstock allocation, this model plans product production and capacity expansion. The ability of model was tested through a case study of future Tehran metropolis.

Competition in Markets for Ancillary Services? The Implications of Rising Distributed Generation

Ancillary services are electricity products which include balancing energy, frequency regulation, voltage support, constraint management and reserves. Traditionally they have been procured by system operators from large conventional power plants, as by-products of the production of energy. This paper discusses the use of markets to procure ancillary services in the face of potentially higher demand for them, caused by rising amounts of intermittent renewable generation.We discuss: the nature of markets for ancillary services; what we really mean by ancillary services; how they are impacted by the rise of distributed generation; how they are currently procured; how they relate to the rest of the electricity system; the current state of evidence on ancillary services markets; whether these markets ever be as competitive as conventional wholesale energy markets, and offer some conclusions.

Are the Responses of Sectoral Energy Imports Asymmetric to Exchange Rate Volatilities in Pakistan? Evidence From Recent Foreign Exchange Regime

Growing energy demand but stagnant production followed by volatile exchange rate leads Pakistan to energy imbalances and potential economic contraction. Yet, studies on sectoral energy imports are limited and inconclusive without accessing the asymmetric effect of currency fluctuations. We examine the impacts of Pakistani rupee volatility on monthly energy imports based on the nonlinear autoregressive distributed lag (NARDL) estimations. Augmented Dickey–Fuller and Phillips–Perron tests were used to conduct unit root testing, and the bound testing approach was used to examine the long-term cointegration. The long-run asymmetry was tested with the Wald test, and using the NARDL model, we examined both short-run and long-run asymmetric effects of exchange rate volatility on energy imports. The bound test was established and supported through ECMt−1 (t-test), cointegrating the relationship between exchange rate volatility and energy imports in a long term. Among others, both short-run and long-run asymmetric effects were found for crude oil, coal, electricity, and petroleum products. Rupee depreciation increased crude oil and electricity imports, while the appreciation effects were insignificant. Overall, the empirical assessment reveals that the foreign exchange volatility effect is sectoral specific and asymmetric in Pakistan. It offers new insights into re-strategizing the energy policy and refining the import substitution plan.

The spatial effects of city-level water-energy nexus: A case study of Hebei Province, China

As the basis of urban social-economic development, water and energy resources are indivisible and interrelated in the production and consumption activities of cities. The frequent intercity trade of energy-related goods aggravates water withdrawal in neighboring cities and causes the spatial transfer of resources. The spatial correlation of water withdrawal and energy consumption is rarely considered in the city-level water-energy nexus. As one of China's most serious water shortage regions, Hebei Province is the third-largest energy consumer in China and is a major supplier of mineral resources, industrial raw materials, water resources, electricity, and agricultural products to Beijing and Tianjin. The spatial Durbin model with the two-way fixed effects is applied to explore spatial effects of water-energy nexus in cities of Heibei province. Seven influencing factors, including energy consumption, energy structure, population, GDP, water withdrawal intensity, urbanization, and agriculture structure were considered. Results showed that all factors had positive impacts on water withdrawal except energy structure. Water withdrawal intensity made the most considerable contribution to water withdrawal, followed by urbanization, energy consumption, GDP, industrial structure, and population. The urbanization level of neighboring cities exerted the most significant positive spatial spillover impact on local water withdrawal, whereas the energy consumption showed a negative impact. The exploration of city-level spatial correlation regarding water withdrawal and energy consumption provides a reference for regional cooperation to improve resource utilization efficiency, establishing sustainable energy and water systems, and promoting sustainable development.

Pay now, save later: Using insights from behavioural economics to commit consumers to environmental sustainability

Focusing on delayed outcomes facilitates goal pursuit, but people exhibit a clear preference for immediate outcomes. Introducing immediate incentives (rewards or penalties) that are contingent on later performance can act as a commitment device to facilitate long-term goal pursuit. Here we apply these behavioural insights to the design of incentive-based electricity products that aim to commit consumers to conserve electricity. Such products are often effective in lowering consumption levels, but their uptake among consumers is relatively low. Across two experimental studies, we tested consumer acceptance of three novel incentive-based electricity products that applied a combination of rewards and penalties to commit consumers to conserve electricity in their homes. Results show that consumers were less likely to choose incentive-based products that offer an upfront reward (combined with a delayed penalty that applies upon failing to reach a conservation target). Our results further indicate that this may be the case because consumers perceived the upfront rewards as a less effective commitment device. Thus, while immediate rewards can be effective commitment devices to long-term goal pursuit, this does not seem to apply in the context of electricity conservation. Moreover, individual differences predicted choices of electricity products: Individual levels of loss aversion and temporal discounting predicted tariff choices, mediated by perceived tariff attractiveness and perceived incentive effectiveness. Our findings highlight the potential for designing behaviourally-informed incentives and energy products as well as the market potential for innovative incentive-based tariffs designed to help consumers commit to long-term conservation goals.

Average residential outage cost estimates for the lower 48 states in the US

Motivated by diverse residential electricity outage cost estimates and possible hypothetical bias of contingent valuation (CV) survey data, this paper proposes a simple formula for market-based estimation of residential outage costs. Its key finding is that average residential outage cost estimates for the lower 48 states of the US range from US$0.12 to US$0.34 per kWh unserved, below the regional CV-based estimates of US$1.0 to US$4.2 per kWh unserved found by a national study. It makes three contributions to the literature of residential outage cost estimation. First, it obviates collecting and analysing CV survey data for estimating average residential outage costs. Second, its proposed formula has minimal data requirements and is applicable to any city, state, region, or country. Finally, it details the policy implications of our newly found empirics in electricity pricing, resource planning, resource procurement, electricity product differentiation, and performance-based regulation of electricity reliability.

Energy and GHG Emissions Aspects of the COVID Impact in Greece

The effects of COVID-19 have had devasting effects on both health and economies in 2020. At the same time, the lockdown and the downturn of economic activity resulted in a decrease in energy consumption and an accompanying reduction in greenhouse gas emissions. In this article, a comparison with the temperature adjustment of energy use is presented for the main carriers of electricity, natural gas, and oil products in the residential, tertiary, industry, and transport (road transport, domestic aviation, and navigation) sectors in 2020 against the previous two years in Greece, along with the corresponding emissions. As the comparison covers the entire year, both COVID peaks in the March–April and November–December periods and the corresponding lockdown effects as well as seasonal variations are included. The analysis shows a reduction, adjusted for temperature, of 3528 GWh in electricity and 10,286 GWh in transport, and an increase of 1916 GWh in heating and other final uses for a net 11,898 GWh decrease and a resulting emissions reduction of 3.48 MtCO2eq (1.29 MtCO2eq in electricity, 2.69 MtCO2eq in transport, and an increase of 0.54 MtCO2eq in heating), or 4.1%, from total national emissions in 2019. The effect is, to a considerable extent, the result of drastic tourist activity contraction, which is starkly evident in the electricity consumption in the Aegean islands. The comparison between the two lockdown periods brings out clear differences, with the reduction in the second one being considerably smaller as the population reverted, to a large extent, to pre-COVID behavior, which implies that no permanent gains from the COVID long-term impact toward decarbonization should be expected.

Energy consumption: The importance of institutional quality in Pakistan

The energy sector of Pakistan has undergone several changes over the previous several years, due to the ever-increasing energy consumption. The objective of this study is to determine the extent to which the consumption of energy sources can be attributed to Pakistan’s institutional quality, based on the perception of positive impact of institutional quality on facilitation of public goods. In this context, the demand functions of energy sources (electricity, natural gas and petroleum products) for four main economic sectors(i.e., residential, industry, commercial and agricultural sectors), have been examined by employing bound testing to cointegration (ARDL approach), over a period of 35 years (1984-2019). The analysis reveals that institutional quality has significant positive impact on energy consumption. The results of the study provide implications for energy sector reforms by illustrating the importance of institution-building policy efforts.

Energy and environmental enhancement of power generation units by means of zero‐flow coolant strategy

Warm-up period is considered as the most critical phase in the operation of any device that converts the energy of a fuel into heat, electricity, and other products, including power generation units since the system efficiency and environmental pollution levels are much worse than the normal operation in that phase. Considering this point, in this study, applying the zero-flow coolant strategy to reduce the warm-up period is suggested for power generation units and it is investigated in details. An internal combustion engine is selected as the case-study and implementation of the method to enhance the performance of that from both energy and environmental aspects are studied comprehensively. As the results show, for the investigated engine, which has a capacity of 1.8 L, implementation of the method leads to 17% decrease in the warm-up period. It is accompanied by 9.32% and 2.23% improvement in the amount of unburned hydrocarbon emission and fuel consumption. Moreover, based on the conducted discussion, despite other available methods to enhance systems that consume fuel, the method is so practical that it could be employed simply in an energy system without imposing a huge cost, which is taken into account as a significant advantage.

Fuel mix disclosure in Germany—The effect of more transparent information on consumer preferences for renewable energy

Electricity suppliers in many countries are legally required to disclose their electricity products' fuel mix, with the objective of helping consumers make more informed electricity purchase decisions. The fuel mix disclosure system in Germany differs from those of many other countries and from that which the European Union demands. While electricity suppliers must list fossil and fissile energy sources individually, the renewable energy sources (RES) are lumped together under the generic terms “renewable energies supported by the EEG” and “other renewable energies.” We investigated whether breaking these generic terms down into their components (photovoltaics, hydropower, wind power, and biomass) impacts consumers' preferences and their willingness to pay for renewables. Our results suggest that consumers are willing to pay more for electricity made from RES when information about the individual RES was provided. We found that a possible explanation for this finding is that consumers perceive the specified RES as less harmful to the environment than the two generic RES and that consumers have poor knowledge about what energy sources these generic RES represent. We therefore recommend German policy makers to move away from the current fuel mix disclosure system toward one that provides more detailed information.

Decentralised Electricity Markets and Proactive Customer Behaviour

The energy transition in Germany takes part in decentral structures. With the ongoing integration of Renewable Energy Sources (RES) into the electricity supply system, supply-side is therefore becoming increasingly decentral and volatile due to the specific generation characteristics. A rather inflexible demand-side, on the other hand, increases the effort to gain the necessary equilibrium between generation and consumption. This paper discusses how consumer behaviour can be influenced by real-time pricing to align demand with generation. Therefore, a combination of two different approaches is used, (I) The Cellular Approach (CA) and (II) Agent Based Modelling (ABM). A model is set up considering a regional energy market, where regional electricity products can be traded peer-to-peer regarding each consumer’s preferences. The observation is made for a whole distribution grid including all types of consumers. The investigations show that energy purchases can be stimulated individually by a flexible pricing mechanism and met preferences. Moreover, benefits occur for the whole region and potentials arise to smooth the exchange balance to the superordinate grid level. Running the model for one entire year in a conservative generation scenario, hours of oversupply could be reduced by 18% and the consumption of green electricity generated regionally could be increased by over 125 MWh within the region itself, in comparison to a base scenario.

Plant-microbial fuel cell with using the lettuce during cultivation by panoponic

The results of the development of an experimental plant-microbial fuel cell (PMFC) construction are presented. It is based on cultivation by the panoponics method and aimed at the joint production of electricity and plant products. The value of bioelectric potentials (BEP) is ~ 100 mV when it is generated in a multi-day mode using a vegetable culture of lettuce. The importance of providing surface electrical contact of roots with electrodes is shown. It is noted that both redox reactions in the nutrient solution and the root system of plants can act as an electromotive force (EMF). It is shown that creating a battery based on the constructed PMFCs, leading to the summation of electrical parameters for a long period (more than 3 days), is possible only in the case of uniformity of the elements included in the electric circuit.

Sudan – Land, Climate, Energy, Agriculture and Development: A Study in the Sudano-Sahel Initiative for Regional Development, Jobs, and Food Security

Sudan is situated in Sub-Saharan Africa, covering an area of about 1.9 million km2 and has a population of 43 million. It is regarded as one of the countries in the world where human development is least advanced with a poverty rate of about 46%. Sudan’s economy is based on agriculture, which contributes about one-third of the (GDP). Sudan’s agriculture has three distinct crop and three distinct livestock production systems. The Crop production systems are: irrigated, traditional and mechanized rain-fed farming. The livestock production systems are: nomadic, transhumant and sedentary systems. The annual cultivated land is around 20 million hectares, more than 85% of which are rain-fed. The livestock population is estimated at 105 million heads concentrated in nomadic and transhumant production systems. Water resources in Sudan are: river Nile and its tributaries, seasonal streams, underground water and surface water. Sources of energy are: biomass; electricity (hydro and fossil fuels) and petroleum products, accounting for about 78,8% and 14%, respectively, of the total energy balance. Sudan has significant renewable energy resources. Particularly solar energy is well distributed all over the country thus having the potential to facilitate the provision of energy services to rural settlements. Sudanese land cover classes indicated that 51% of the country area is bare rocks and soil, agriculture land is 13%, and tree cover and herbaceous vegetation cover 36% of the total Sudan area. The annual crop cultivated area is around 20 million ha and the main crops occupying more than 90% of the cultivated area are sorghum, millet, wheat, sesame and groundnut. Rangelands are the backbone of the livelihood of pastoralists and agro-pastoralists producing annually about 73% of the total feed required for national herds. The forest area is about 22 million ha thus comprising three different classes: federal, state, and community/private forests. Sudan is one of the most seriously affected countries by desertification in Africa. Recent GIS and remote sensing results indicated that between 1958 and 2017 the desert boundary was moved more to the south pushing the country into a historical desertification disaster. Several attempts were made to formulate regulations and legislations to combat soil degradation and desertification. However, desertification in Sudan remains a major environmental threat. Sudan is among the most vulnerable countries in the world to climate change, ranking 175th out of 181 countries. Analyses of rainfall and temperature have demonstrated a high rainfall variability and a clear rise in maximum and minimum temperature. Key climate change impacts include: reduced crops and livestock productivity, reduction in the duration of the growing season and socioeconomic impact such as conflict over resources and migration to urban centres. Sudan has implemented several plans and policies which directly relate to climate change adaptation and development priorities. The focus of these plans and policies is: food security and raising productivity, reducing poverty and enhancing adaptation and resilience to climate change, protecting and developing natural resources, land tenure problems and strengthening governance and institutional capacity. These interventions had limited success in achieving their objectives. The main reasons are: a lack of political stability and fluctuating economic and financial policies as well as weak administrative and implementation capacity of the government institutions. The main lessons learnt are: agricultural-development programmes require increased and more effective public and private partnerships involving the main stakeholders. The low flow of finance to the agricultural sector remains one of the obstacles of agricultural growth. In addition to the poor rural infrastructure, the ongoing conflicts and social unrest in many parts of the country are strongly impacting the performance of the economy and constraining the development plans and policies.

The Model of the Five Competitive Forces on Portuguese Electricity Market

In Portugal, the energy sector apparently shows lack of efficiency as the amount of energy used to generate a unit of GDP, also called energy intensity of the economy (TPES/GDP), an indicator of energy efficiency, which decreased in Portugal in a couple of decades less than in the EU 27 overall. The TPES/GDP indicator stills high in most Portuguese economic sectors in comparison with the EU27 average. To determine the reasons of such lack of energetic efficiency this work aims to analyze the Portuguese electricity market based on the model of the five competitive forces of Michael Porter that was chosen due to the idiosyncrasies of electricity sector, of strategies highly anchored on its external competitive setting and of little innovation around a non-differentiated electricity product of extended life cycle. Firstly, the theoretical aspects of the model are explained; secondly, it is made a critical review, including the reasons for choosing it; thirdly, the model is applied to the electricity market in Portugal and finally the main findings are revealed. The main methodology used is literature review of secondary sources and data. Authors mainly relied on sources of high-quality material. The input data has been collected from national institutes and from the information offered by the main players on their web sites. These sources are certified, and the input information is supported by their credibility and by the supervision departments. Portugal, due to the Country dimension and the barriers, the players are still few, and the electricity market is concentrated. The competition is high among 3 - 4 major players; the barriers are high; the electricity of traditional national suppliers is high although mitigated by the entry of other European Union distributors; the bargaining power of consumers is low and the substitutes are inexistent. Moreover, the equipment in consumption is aggregated to electricity, which is not easy to change. As electricity cannot be differentiated, energy distribution companies need to set strategies to engage consumers. The present paper reflects and analyses on these assumptions and concludes that to augment energetic efficiency, companies in energy markets as Portugal must prioritize diversity, complementary services and non-related products. Also, the low degree of competition has no conditions to be surpassed in the near years due to the inefficient features of the energy market and subsequent barriers.

Towards upscaling microbial desalination cell technology: A comprehensive review on current challenges and future prospects

Abstract Shortage of potable water is the driving force behind desalination practices mainly performed by conventional thermal and membrane-based technologies. However, conventional desalination technologies are unsustainable due to their high energy requirements. This highlights the necessity of developing more sustainable and eco-friendly alternatives. As an emerging technology, microbial desalination cell (MDC) has attracted a great deal of attention due to its ability to desalinate seawater, treat wastewater, and recover electricity and value-added products in a single reactor. The technology produces electricity through the biodegradation of organics present in wastewater. The recovered electricity derives the migration of ions, and is subsequently collected as value-added product. The present review summarizes the prospects of MDC as (i) a sustainable green desalination technology, (ii) a cost-effective approach for simultaneous wastewater treatment and recovery of value-added products (i.e., HCl, NaOH, H2O2, H2, humic and fulvic acid), and (iii) an electrochemical process for + removal of targeted pollutants (i.e., NH4+-N, Cu, Cr, Pb, Ni, As). Despite the favorable environmental and economic attributes of MDCs, large-scale application of those technology is limited due to a number of engineering and operational challenges. Therefore, this review carefully summarizes all the challenges associated with engineering parameters (i.e., reactor design, internal resistance, cost-effectiveness of electrodes and membranes, membrane fouling), and operating factors (i.e., pH imbalance due to ion migration, low ion transport rate, growth and adhesion of electroactive biofilms, and biofilm inhibition). The interrelationships between the engineering/operational challenges and MDC performances are also concisely explained. Finally, research needs to scale up MDCs for simultaneous desalination, wastewater treatment, and energy-resource recovery are proposed.