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Globally, waste management has been a topical issue in the past few decades due to the continual increase in municipal solid waste (MSW) generation that is becoming difficult to handle with conventional waste management techniques. The situation is much more pronounced in economically developing countries where population growth rate and urbanisation are becoming uncontrollable. The purpose of this study was to assess the potential for waste to energy generation in the Kumasi metropolis, the second-largest city in Ghana.

To address the objectives of the study, a quantitative research approach, namely, the questionnaire was adopted. The data analysis was done using the statistical package for social sciences version 25, including both descriptive and inferential statistics to give an in-depth meaning to the responses from the participants.

The results showed that several factors hinder waste to energy technology in Ghana; key among them was high capital cost, high operational cost and lack of governmental support and policy framework. The results also revealed that 1 m³ of biogas generated from MSW in Kumasi could generate 36 MJ of energy, equivalent to 10 kW/h.

The unique contribution made by the paper is that it combines expert opinions, empirical data that included time series data and opinion of key actors in the waste management chain in assessing the potential for waste to energy generation in the Kumasi metropolis of Ghana.

The purpose of this paper is to develop a methodology for assessing the effects of global and regional externalities that create traditional power generation industries and to propose a transition to a tariff strategy taking into account these consequences. The main purpose of the research is to analyze the current wholesale electricity tariffs in the energy market of Ukraine and propose their assessment taking into account external effects for other sectors of the economy.

At the first stage, according to observations for 2004–2019 on the amount of pollution and the cost of agricultural products in some regions of Ukraine, which is provided in 2010 prices, the impact of hazardous emissions on the cost of agricultural products was analyzed in each region. The use of panel regression allowed to combine spatial and temporal studies (12 separate areas and time interval 2004–2019). To assess the external effects of heat generation, panel regression was used, which made it possible to combine spatial and temporal data on the impact of pollution on the efficiency of agricultural production and add regional losses of agricultural business to the cost of heat generation. This paper uses optimization models to maximize the function of public utility of electricity generation, making allowances for externalities.

This research assesses the negative externalities of Ukraine's energy and confirms the need for a global transition to a low-carbon economy primarily through climate finance. The analysis revealed the presence of various influences of the factor of regional air pollution and time. The hypothesis of the existence of a negative impact of local air pollution on agricultural production has been confirmed. An increase in emissions by 1,000 tons leads to an average decrease in regional agricultural production by UAH 84 million (at the prices of 2010).

The optimization problem of the ratio of different types of generation is set on the basis of maximizing the function of social utility of electricity generation, taking into account external effects. The authors presented an optimization model of electricity generation, which corresponded to the state of the energy market for 2019, provides an opportunity to assess the contribution of the inverse external effects of each electricity sector and to estimate external tariffs for each electricity generation sector.

Green energy as a transportation supply trend is irreversible. In this paper, a highway energy supply system (HESS) evolution model is proposed to provide highway transportation vehicles and service facilities with a clean electricity supply and form a new model of a source-grid-load-storage-charge synergistic highway-PV-WT integrated system (HPWIS). This paper aims to improve the flexibility index of highways and increase CO₂ emission reduction of highways.

To maximize the integration potential, a new energy-generation, storage and information-integration station is established with a dynamic master–slave game model. The flexibility index is defined to evaluate the system ability to manage random fluctuations in power generation and load levels. Moreover, CO₂ emission reduction is also quantified. Finally, the Lianhuo Expressway is taken as an example to calculate emission reduction and flexibility.

The results show that through the application of the scheduling strategy to the HPWIS, the flexibility index of the Lianhuo Expressway increased by 29.17%, promoting a corresponding decrease in CO₂ emissions.

This paper proposed a new model to capture the evolution of the HESS, which provides highway transportation vehicles and service facilities with a clean electricity supply and achieves energy transfer aided by an energy storage system, thus forming a new model of a transportation energy system with source-grid-load-storage-charge synergy. An evaluation method is proposed to improve the air quality index through the coordination of new energy generation and environmental conditions, and dynamic configuration and dispatch are achieved with the master–slave game model.

In order to accurately predict the uncertain and nonlinear characteristics of China's three clean energy generation, this paper presents a novel time-varying grey Riccati model (TGRM(1,1)) based on interval grey number sequences.

By combining grey Verhulst model and a special kind of Riccati equation and introducing a time-varying parameter and random disturbance term the authors advance a TGRM(1,1) based on interval grey number sequences. Additionally, interval grey number sequences are converted into middle value sequences and trapezoid area sequences by using geometric characteristics. Then the predicted formula is obtained by using differential equation principle. Finally, the proposed model's predictive effect is evaluated by three numerical examples of China's clean energy generation.

Based on the interval grey number sequences, the TGRM(1,1) is applied to predict the development trend of China's wind power generation, China's hydropower generation and China's nuclear power generation, respectively, to verify the effectiveness of the novel model. The results show that the proposed model has better simulated and predicted performance than compared models.

Due to the uncertain information and continuous changing of clean energy generation in the past decade, interval grey number sequences are introduced to characterize full information of the annual clean energy generation data. And the novel TGRM(1,1) is applied to predict upper and lower bound values of China's clean energy generation, which is significant to give directions for energy policy improvements and modifications.

The main contribution of this paper is to propose a novel TGRM(1,1) based on interval grey number sequences, which considers the changes of parameters over time by introducing a time-varying parameter and random disturbance term. In addition, the model introduces the Riccati equation into classic Verhulst, which has higher practicability and prediction accuracy.

The purpose of this study was to design a renovation plan for a university campus building (Department of Electrical and Computer Engineering) with the aim to achieve nearly zero energy performance, ensuring a low specific demand (lower than 44 kWh/m²) and a high level of on-site renewable generation (equivalent to more than 20 per cent of the energy demand).

The baseline demand was characterized based on energy audits, on smart metering data and on the existing building management system data, showing a recent reduction of the electricity demand owing to some implemented measures. The renovation plan was then designed with two main measures, the total replacement of the actual lighting by LEDs and the installation of a photovoltaic system (PV) with 78.8 kWp coupled with an energy storage system with 100 kWh of lithium-ion batteries.

The designed renovation achieved energy savings of 20 per cent, with 27.5 per cent of the consumed energy supplied by the PV system. This will ensure a reduction of the specific energy of the building to only 30 kWh/m², with 42.4 per cent savings on the net-energy demand.

The designed renovation proves that it is possible to achieve nearly zero energy goals with cost-effective solutions, presenting the lighting renovation and the solar PV generation system a payback of 2.3 and 6.9 years, respectively.

This study innovated by defining ambitious goals to achieve nearly zero energy levels and presenting a design based on a comprehensive lighting retrofit and PV generation, whereas other studies are mostly based on envelope refurbishment and behaviour changes.

When the power generator faces uncertain and independent electricity spot price and renewable energy source supply, two different conditions need to be considered: the distributions of renewable energy source electricity and electricity spot price are independent or dependent. The purpose of this paper is to explore the capacity investment strategy under volatile electricity spot price when renewable energy penetration rate is low, taking into account these two conditions.

The authors design a capacity investment model under dual uncertainties and consider how to optimize the investment capacity in order to maximize profit under two different conditions.

The authors find that when renewable energy supply fluctuation is unrelated to spot electricity price fluctuation, the renewable energy power profitability is determined by the average cost of spot electricity price and equivalent cost. When renewable energy supply fluctuation is related to spot electricity price fluctuation, the renewable energy power profitability is determined by the market value and the construction and maintenance cost.

Faced with the conflict of the renewable energy supply, the authors need to understand how to plan the generation capacity with intermittent renewable sources. The result helps renewable energy become competitive in the electricity market under loose regulations.

The authors compare two capacity investment strategies that the renewable energy supply fluctuation is related and unrelated to spot electricity price.

The ex-post literature, which evaluates the real impact of renewable generation, is scarce. Most studies are simulations and therefore are not based on real data. This study aims to further this goal using a unique database of the Portuguese spot market, where there are powerful incentives for renewable electricity.

This paper analyses ex-post the impact of energy produced in special regime on the wholesale hourly spot market prices of Portuguese electricity during the period 2009–2016. This paper uses standard, two stage least squares and generalized method of moments multivariate regressions and other energy econometrics techniques.

It is found that special regime generation has a negative impact on the wholesale price. This impact is higher than that found in other markets. This paper also concludes that using special regime generation to supply the future growth of demand will decrease wholesale electricity spot prices more intensively than using other technologies.

This paper uses a unique database based on ex-post for the Portuguese spot market. The Portuguese case is particularly interesting, not only because of its strong incentives policy on renewable energy but also because its spot market is interconnected with the Spanish market. This paper contributes to the debate about the sustainability of current renewable electricity support schemes. The decreasing trend in electricity prices, with the introduction of new renewable capacity, can be incompatible with the required payments for non-renewable producers. This paper also shows that even if the price reduction on spot markets is transferred to final consumers, given that it is relatively small (8% spot price which represents 45% of the final price), compared with the cost of incentives (35% of the final price), consumers probably will not be able to support a new investment pipeline with a similar framework.

Kumasi Metropolis, the second-largest city in Ghana is known to be bewildered with challenges relating to waste management. As a means of solving the waste management challenge, several suggestions are often made for the establishment of a waste-to-energy plant to manage the disposal of waste and generation of income. There have been no studies conducted to determine how economically viable such plants will be. This study aims to examine the economic viability of waste-to-energy generation in the Kumasi Metropolis to find out how economically viable such an approach will be.

To achieve this, a simple debt-equity ratio business model based on discounted cash flow technique was applied to estimate the internal rate of returns (IRR) as a measure of the economic viability and profitability of a modelled 50 MWH waste-energy generation plant in the Kumasi Metropolis. The analysis was performed using the RetScreen Expert Software.

The results show that the IRR and benefits cost ratio of the facility were 36% and 5.8%, respectively, indicating high levels of profitability and economic viability. The study concludes that waste-to-energy generation will be an economically viable venture in the Kumasi Metropolis.

It is, however, important for users of the findings of this study to take caution of the fact that the various assumptions although based on current knowledge and expert opinion may vary with time; therefore, the sensitive analysis on price and costs should always be considered. Practically, this study will contribute to solving the waste management situation in most cities, as well as generating revenue and helping close the energy deficit most developing countries are grabbling with.

The unique contribution of the study to knowledge is that it has professed an alternative analytical and methodological approach to measuring the financial viability of waste-to-energy plants in situations where there is none in the geographical jurisdiction of the proposed project.

Renewables such as sugar-energy biomass can contribute to national electrical security, job creation and mitigation of greenhouse gas emissions. However, after the auction of reserve energy, in 2008, exclusive biomass, in the regulated contracting environment (RCE), the authors observe that this energy environment has lost competitiveness in the auctions. Thus, a study on the present theme is justified, based on the problem: What are the reasons for the lack of competitiveness of sugar-energy bioelectricity in the Auctions of the RCE of the National Electric Energy Agency? The purpose of this study is to understand the situation of sugar-energy bioelectricity in the Brazilian market.

Literature review was conducted through the Scientific Electronic Library Online database, as well as the survey of primary documents at Sugarcane Industry Union and Electric Energy Trading Chamber.

The reasons for lack of competitiveness in RCE electricity auctions are: distant location of transmission lines; difficulties in obtaining licensing; delay in responses from environmental agencies; difficulties in securing financing for electricity generation projects for distilleries; non-pricing of positive environmental externalities as adequate disposal of waste; and the non-recovery of the cost of retrofit of the plants. The present situation may create economic, social and ecological circumstances adverse for Brazilian development, such as a lack of employment and income generation, loss of international currencies from imports of technologies not developed and produced in the country and more significant inefficiency greenhouse gas mitigation.

The originality of this study is in the contribution to the scarce literature on the understanding of the reasons for the lack of competitiveness of the Brazilian sugarcane sector in auctions of the regulated energy environment, based on SWOT analysis and, based on this understanding, to propose solutions for the expansion of this important matrix energy.

The purpose of this paper is to evaluate the green energy generation potential of the organic fraction of municipal solid waste (OFMSW) through anaerobic digestion (AD) route in India and its benefits.

In this study, performances of some AD plants presently operating successfully in India have been studied in the field (Section 3.1). Primary data collected from this study has been used to evaluate the biogas generation potential of OFMSW in Indian condition (Section 4). To ensure the validity, this gas generation potential has been compared with the gas yield data observed by the other researchers and with the gas yields of AD plants of some technology providers at some parts of the world (Section 4.1). From the future population projection (year 2030) and the future per capita waste generation rate obtained from the literature survey, estimation has been made for future quantity of municipal solid waste (MSW) (year 2030) (Section 2.3). Based on these data, the green energy generation potential from the bio-degradable portion of MSW through AD route, in India, has been evaluated (Section 4.2), and its economic and environmental benefits have been analyzed (Section 5) .

This secondary research work reveals that from the bio-degradable portion of MSW, India can generate about 583 MW of green energy daily and produce about 5.1 mil MT of bio fertilizer per annum presently, and these may go up to 2,273 MW and 19.5 mil MT, respectively, in the year 2030. Generation of green energy from OFMSW, in India, may save coal consumption of about 3.04 mil MT and reduce 35.42 mil MT of CO₂ emissions per annum presently. Moreover, utilization of the bio-degradable portion of the MSW stream may save about 550 acres (2.23 sq. km) of landfill area per year presently and in total may save about 8,182 hectare (82.5 sq. km) of landfill area during the period of 15 years time.

The population growth and future per capita waste generation rate are based on census report of Govt of India and survey report of World Bank, respectively. Separate collection of bio-degradable portion of MSW has not yet been developed properly in India.

This study reveals that in India, the high-moisture-content, low-calorific-value bio-degradable waste in India can be used for the generation of substantial amount of green energy in India, which in addition to financial gains would reduce the waste quantity at landfill site, conserve natural resources, save land, reduce green house gas emission, generate employment and help to protect environment. Considering these benefits and advantages, evaluated in this study, policy makers and city managers may review their approaches toward solid waste management system of their cities to meet the challenges of huge increase of MSW in the years to come in India. More research works may be initiated to improve the AD system of organic waste, and more capital may be employed in waste management business in India.

Numbers of research works have been carried out by other researchers for estimation of energy generation potential through AD of OFMSW for different countries; but no such work could be found to identify such potential and its benefits in India. This research work demonstrates how MSW can be used as a wealth for green energy production in India. The originality of this paper is the analysis of green energy generation potential from the low calorific value MSW in India.