Biomass-based Power Research Articles

Mechanical, durability, and microstructural characteristics of rice-straw-ash-based clay bricks: a sustainable approach to utilize biomass-based power plant waste

Mechanical, durability, and microstructural characteristics of rice-straw-ash-based clay bricks: a sustainable approach to utilize biomass-based power plant waste

Optimization of a Biomass-Based Power and Fresh Water-Generation System by Machine Learning Using Thermoeconomic Assessment

Biomass is a viable and accessible source of energy that can help address the problem of energy shortages in rural and remote areas. Another important issue for societies today is the lack of clean water, especially in places with high populations and low rainfall. To address both of these concerns, a sustainable biomass-fueled power cycle integrated with a double-stage reverse osmosis water-desalination unit has been designed. The double-stage reverse osmosis system is provided by the 20% of generated power from the bottoming cycles and this allocation can be altered based on the needs for freshwater or power. This system is assessed from energy, exergy, thermoeconomic, and environmental perspectives, and two distinct multi-objective optimization scenarios are applied featuring various objective functions. The considered parameters for this assessment are gas turbine inlet temperature, compressor’s pressure ratio, and cold end temperature differences in heat exchangers 2 and 3. In the first optimization scenario, considering the pollution index, the total unit cost of exergy products, and exergy efficiency as objective functions, the optimal values are, respectively, identified as 0.7644 kg/kWh, 32.7 USD/GJ, and 44%. Conversely, in the second optimization scenario, featuring the emission index, total unit cost of exergy products, and output net power as objective functions, the optimal values are 0.7684 kg/kWh, 27.82 USD/GJ, and 2615.9 kW.

Assessing the Potential of Biomass Power Generation for Renewable Energy Transition in South Papua Province, Indonesia

This study aims to explore the potential for biomass-based power plant to accelerate the development of renewable energy to replace the role of fossil energy in Merauke district, South Papua Province. The method used in this study is, first, to collect data and analyze the load on the grid system and the portion of the energy mix as well as the availability of woody biomass from forest areas by making a simulation of the development of a 2 x 12 MW Biomass Power Plant. Second, by conducting experiments to obtain woodchip conversion, as the fuel of the Biomass Power Plant, from the wood log and conversion from Biomass Power Plant capacity to the required biomass plantation area. The results provide an overview of the big potency for developing biomass-based power generation by utilizing biomass from the local industrial plantation forest and show the energy transition towards energy independence. This study can be useful for policy makers and opportunities for entrepreneurs or suppliers of wood biomass, as well. For the future, in terms of fuel efficiency, it is necessary to reduce the plantation area as a source of biomass for power plants by reducing the moisture content of the woodchip to increase the calorific value and utilizing the forest residue. Furthermore, the comparison cost study between fossil power plant and biomass power plant, as well as the strategy for preserving the plantation to ensure a steady biomass supply is conducted.

Optimization of a proposed biomass generator: Harnessing citizen waste with electric vehicle charging infrastructure

Global municipal solid waste production is rising, causing significant environmental, health, and economic issues. Developed countries have advanced recycling technologies, but cities like Dhaka, Bangladesh—among the most densely populated-struggle with inadequate waste management. This feasibility study aims to improve environmental protection and create new energy sources by proposing a waste management system across Dhaka, focusing on waste valorization for bioenergy with optimized efficiency and minimal impact. The study includes design and optimization of a biomass-based power plant to meet the energy needs of EV charging stations and the national grid, evaluating its economic performance through discounted cash flow and payback period analyses. The paper explores the integration of an EV charging station powered by biogas, addressing the growing need for EV infrastructure in Dhaka. By evaluating biomass generators as a greener alternative to fossil fuels, the study analyzes the technical, economic, and environmental feasibility, including CO2 emissions, using HOMER Pro.

Economic/sustainability optimization/analysis of an environmentally friendly trigeneration biomass gasification system using advanced machine learning

The present research presents an innovative thermal integration model for a biomass-based power plant to generate power, coolant, and liquefied hydrogen. This integrated arrangement comprises biomass gasification, gas turbine cycle, organic flash-bi-evaporator refrigeration cycle, multi-effect desalination, solid oxide electrolyzer, and Claude cycle. The selection of an eco-friendly fluid for the electricity-cooling production cycle is conduced relying on a comparative analysis. The subsequent examination evaluates the economic-sustainability performance criteria through sensitivity and contour analyses. The comparative assessment identifies R1234ze(Z) as the most suitable working fluid. Four objective functions are scrutinized, and two optimization scenarios are devised based on a machine learning approach using artificial neural networks and a multi-objective gray wolf optimization technique. In Scenario A, the focused objectives are the total destructed exergy and the cost of producing liquefied hydrogen. Meanwhile, Scenario B integrates the sustainability index and the overall system cost rate as primary criteria. Scenario A exhibits more favorable operational conditions and outcomes than scenario B, showing the objectives mentioned as 9955 kW and 3.25 $/kg, respectively. In this scenario, the sustainability index, the overall investment cost rate, and the net present value are obtained to be 1.74, 236 $/h, and 205 M$, correspondingly.

Process development and multi-criteria optimization of a biomass gasification unit combined with a novel CCHP model using helium gas turbine, kalina cycles, and dual-loop organic flash cycle

The non-renewable nature of conventional power plants and the challenges associated with fuel costs and environmental impact highlight the need for innovative solutions. This research proposes a biomass-based combined system designed to produce multiple products, including electric power, coolant, and heat, addressing the drawbacks associated with conventional power generation. The proposed system integrates a biomass gasification unit with a helium gas turbine and a Kalina power unit. Additionally, a domestic water heater is incorporated into the Kalina cycle for heat generation, and the heat loss from the helium gas turbine is utilized in a modified Kalina cycle with a refrigeration unit. To further enhance efficiency, a dual-loop organic flash cycle is employed to recycle waste heat from the modified Kalina cycle. The analysis of this framework encompasses technical aspects, including energy, exergy, and economic considerations. The system is optimized using the multiple-objective particle swarm optimization method. Two scenarios are explored based on the desired product capacities: heat-electric power and coolant-electric power. In the first scenario, the system demonstrates an optimal electric power generation capacity of 6239.56 kW, along with favorable exergetic and economic outcomes. The optimal exergetic efficiency, net present value, and payback period are determined as 35.57 %, 15.07 M$, and 3.97 years, respectively. This research presents a comprehensive approach to biomass-based power generation, considering both technical and economic aspects, and provides valuable insights for sustainable energy solutions.

Biomass-Based Microgrid: A Case Study on its Aspects in the State of Punjab in India

The microgrid is an emerging power system. It works on the interconnection of renewable energy resources (RES) such as solar, wind and biomass, which is a promising field for researchers to explore the scope of power production from unconventional energy resources. Various combinations of RES like solar, wind, biomass and small-hydro power plants are available at different geographical locations. As a result, the combined use of various RES is drawing more attention and is frequently employed as an alternative to energy based on fossil fuels. Economic facets of these systems are suitably promising to consider them for raising the growth of power generation capability in developing countries. Objective of this paper is to presents a detailed study of the biomass-based hybrid renewable energy systems (HRES) in terms of their cost of energy and carbon emission. Moreover, the deployment of biomass-based power generation technology in Indian and international energy scenarios has been discussed showing the availability along with the availability of RES in Punjab, India. From the literature review it reveals that a viable configuration of microgrid which can generate power by direct combustion and gasification of biomass should be proposed and optimized to ensure more reliability and less carbon footprints in power generation.

A potential coupling of reforming and electrolysis for producing renewable hydrogen from landfill gas

Organic sold waste disposed of in landfills undergoes a mostly anaerobic process which generates a mixture of methane (CH4), carbon dioxide (CO2) and other various gases such as nitrogen, oxygen, sulphides, and non-methane organic compounds (NMOC), known as landfill gas (LFG). Being composed mostly of CH4 and CO2, landfill gas is a potent greenhouse gas (GHG). As a result, various waste treatment interventions are required to minimize the potential catastrophic damage to the environment from direct greenhouse gas emissions from landfills. One effective solution is combustion to generate electricity exploiting methane’s flammability properties. Biomass-based power plants have been present for decades. However, the combustion process is accompanied by a remarkable production of thermal energy which is typically not exploited and therefore lost to the ambient. The current work presents an energetic solution to manage organic waste by employing green hydrogen production. To do so, a hybrid layout based on a cogeneration unit (CHP) fed with landfill gas is considered. The electrical power produced by the CHP is used to produce hydrogen through low-temperature water electrolysis. Furthermore, due to the significant waste heat available in the system, excess thermal power is employed for the methane steam reforming process through a heat recovery section. Hydrogen produced from the reforming section is green since the input is from landfill gas, which is considered renewable. The levelized cost of hydrogen produced from such a hybrid layout is obtained and compared with non-renewable sources in this field. In addition, the annual H2 production rate is calculated for a capacity factor equal to 70%. The results show an annual Hydrogen production of about 167 t/y. LCOH at the stack of about 2 €/kg is reported.

Economic assessment and optimization of low-carbon biomass-based power, methane, and methanol production

Fuel synthesis through CO2 hydrogenation is receiving much attention to decarbonizing the transport sector of future energy systems. In this study, an integrated system is proposed and investigated from a thermo-economic point of view to produce power and synthetic methane and methanol. The proposed system includes an externally fired gas turbine, Rankine cycle, organic Rankine cycle, proton exchange membrane electrolyzer, molten carbonate fuel cell and methane and methanol synthesis units. CO2 hydrogenated under three different scenarios to produce methane-only, methanol-only and dual-production assuming various operating loads of electrolyzer. The influence of the key parameters on the system performance is assessed via response surface method and finally, the system performance is optimized. Under the base conditions, overall exergy efficiency, levelized cost of electricity, methanol and methane is estimated to be 36.8 %, 37.6, 92.8 and 79.4 $/MWh, respectively. Under the optimized conditions for the methane-only scenario, the overall exergy efficiency, levelized cost of electricity and methane is found to be 34.8 %, 36.7 $/MWh and 77.3 $/MWh, respectively.

Design and energy, exergy, and exergoeconomic analyses of a novel biomass-based green hydrogen and power generation system integrated with carbon capture and power-to-gas

The conversion of thermal energy into electrical power through combustion in combined cycle power plants is a prevalent method of energy conversion. Sustainable energy management requires effective energy storage, and power-to-gas (P2G) technology is a recent solution to this problem. In this research work, a novel biomass-based power plant is proposed, this specific type of biomass is composed of industrial wood chips and wheat straw chopped wood with a 3.48:1 mass ratio and 19 wt% moisture. Detailed energy, exergy, and exergoeconomic analyses are performed for each component, considering various ambient and system conditions. This power plant is also equipped with a carbon capture and storage system, by which combustion's carbon dioxide is separated, and a power-to-gas energy storage system, by which hydrogen and oxygen gases are produced, allowing it to produce synthetic natural gas by the methanation process with various industrial applications and reduce carbon emissions. The energy and exergy analyses show that the overall energy efficiency and exergetic efficiency of the plant are 56.49 % and 35.48 %, respectively, which are highly acceptable and feasible. The combustion chamber is the primary location of exergy destruction, accounting for 52 % of the total exergy destruction in the cycles, followed by the methanation unit (15 %) and the turbine (12 %). Furthermore, the effect of modified ambient and manual operational parameters on the overall performance of the plant is analyzed, increasing the gas turbine inlet temperature improves the plant's energy efficiency to 57 %; but leads to a negative impact on its exergy efficiency (32 %), which manufacturing barriers make it difficult to increase beyond 1600 °C. Building the plant in a warmer geographic location barely impacts the energy efficiency; however, it may cause a decline as high as 1 % in the exergy efficiency.

A comprehensive analysis of biomass energy in India for agricultural and domestic use

Biomass is an abundant and renewable resource in India, with vast potential for use in energy production, agricultural applications, and waste management. The country has made significant strides in developing and utilizing biomass resources for various purposes in recent years. One of the primary uses of biomass in India is for energy production. Biomass fuels, such as wood chips, agricultural residues, and municipal waste, are used in rural areas for cooking and heating. Additionally, the government has implemented policies and initiatives to promote the use of biomass for electricity generation. Biomass-based power plants have been established nationwide, with a total installed capacity of over 9,000 MW. Biomass is also used in agricultural applications in India. The country is a major producer of sugarcane, and bagasse, a byproduct of sugarcane processing, is commonly used as a feedstock for producing biofuels and biogas. Additionally, farmers are increasingly using biomass-based fertilizers and pesticides to improve soil health and reduce chemical inputs. Regarding waste management, biomass is a valuable resource for converting organic waste into useful products. Anaerobic digestion and composting are popular methods for treating organic waste, with the resulting biogas and compost being used for energy generation and agricultural applications, respectively. Overall, biomass is an essential resource for India, providing energy, supporting agriculture, and promoting sustainable waste management practices. With continued investment and innovation, biomass has the potential to play an even more significant role in the country's energy and agricultural sectors in the coming year.

Forest Biomass Feedstock Availability and Economic Contribution of Biopower Facilities in the Lake States Region

Abstract The Lake States (MI, MN, WI) region holds 54.8 million acres of forest and offers the potential to meet the increasing demand for sustainable energy through forest biomass. The objective of this study is to estimate the annual availability of biomass, after considering the sustainability threshold, for a wood price and its economic impact in the Lake States region. This study identified twenty-seven active power facilities using biomass in addition to oil, gas, and coal, with a total capacity of 3.85 million MWh per year. They consumed 2.80 million dry tons of biomass in 2019. At the current delivered wood price, an additional 9.72 million dry tons of biomass is economically available, which, if used, would generate an additional 11,112 jobs (1,583 direct and 9,529 indirect and induced), $1.54 billion in value added ($803 million direct and $733 million indirect and induced), and $2.71 billion ($1.46 billion direct and $1.25 billion indirect and induced) in total output. Operating at least one-third of the existing capacity for biomass-based power generation would add 1,969 jobs, $293 million in value added, and $413 million in total output. The expansion of the biomass biopower industry has the potential to significantly increase economic impact, especially in rural areas. Study Implications: Mapping procurement zones for resource allocation using delivered wood prices for biomass helps identify the economic availability of biomass for electric power production in the Lake States. Our results establish the market extent for biomass and identify potential areas where investment in biopower production or capacity upgrade is feasible. This study also provides insight into the economic impacts of additional biomass utilization to produce power. Most of these impacts would come about in rural areas, improving economic growth in these communities. A combined analysis estimating the potential supply and demand and the economic effects of biopower industry expansion provides valuable insight into decision-making for state forest action plans and private sector forest management plans. Furthermore, the findings from this study will help inform effective regional policy and investment decisions on biomass power industries. The method used can also be tailored to a specific facility to estimate its procurement zone, feedstock availability, and economic impacts.

Effect of O2 transport membrane and CO2 capture membranes on the performance of the biomass-based power generation: An artificial intelligence based multi-objective optimization and techno-economic and environmental evaluation

One of the most important causes of global warming is the release of carbon dioxide (CO2) gas into the atmosphere due to the production of electricity to meet the global community's need for energy. The main goal of this research is to present a power generation system based on biomass gasification equipped with a membrane-based carbon capture system. In this system, a gasifier and an oxygen transport membrane (OTM) were coupled with each other to produce pure O2 as a gasification agent. Moreover, a three-membrane system is considered to separate CO2 from combustion gases coming out of the combined Brayton-Rankin cycle. The desired system has been carefully examined from a thermodynamic outlook. In the next step, the cost of electricity has been obtained by using a detailed economic study, taking into account the life of the employed membranes. Finally, by using artificial intelligence (AI)-based multi-objective optimization, the presented system has been optimized from the economic point of view and thermodynamic performance. The results of this research show that the use of OTM to produce pure oxygen as a gasification agent leads to a 53% improvement in the heating value of the produced fuel compared to the use of air (without OTM). Furthermore, the use of CO2 capture membranes (CCM) led to the reduction of annual CO2 emissions from 50.41 Mkg to 9.9 Mkg. According to the Pareto front, the results obtained from the minimization of the electricity cost and the maximization of the net power production showed that the minimum electricity cost and the maximum produced power were 0.4275 $/kWh and 7039 kW, respectively. It can be acknowledged that the optimization and the addition of the carbon capture system in the carbon tax of 303$/Tonne-CO2 (and more than that) not only can produce electricity at a lower cost, but also reduce the amount of CO2 emission from 50.43 million kilograms per year to of 6.9 million kilograms per year.

Designing globalized robust supply chain network for sustainable biomass-based power generation problem

The utilization of renewable energy sources to produce electricity is capable of relieving the pressure of limited natural resources and achieving the sustainability of future energy. This paper addresses a multi-period multi-feedstock multi-technology biomass-based power generation supply chain planning problem with parameter uncertainty, balancing economic, environmental, and social objectives simultaneously. However, the main challenges in optimizing this problem are correlated with multiple conflicting objectives and uncertain parameters. This study proposes a novel globalized robust goal programming model with goal constraints to balance three conflicting objectives using priority levels and characterize the uncertainty of unit emissions and social scores by inner–outer uncertainty sets. After transforming globalized robust environmental and social goal constraints into their equivalent forms, the tractable counterpart of the proposed model is obtained, which is mixed-integer linear programming (MILP). Finally, the effectiveness of the proposed model is demonstrated through a case study about the design of a sustainable biomass-based power generation supply chain (SBPSC) network in Hubei Province, China. Computational results reveal that by adjusting several parameters, environmental and social aspired goals consistently can achieve, whereas the economic objective is vulnerable to being influenced. Comparative studies with nominal goal programming model and robust goal programming model indicate that the proposed model is uncertainty-immunized and less conservative. Under investigated circumstances, the realized economic profit by the proposed model is approximately 42.5% higher than that of the robust goal programming model on average.

Potential utilization of regional cashew nutshell ash wastes as a cementitious replacement on the performance and environmental impact of eco-friendly mortar

Globally, agro-waste ashes are increasing significantly due to the rapid implementation of biomass-based power plants. In the present trend, agro-wastes are disposed of in an unsustainable manner. The recycling of agro-waste has significantly contributed to sustainable goals. In the construction sector, it is possible to dispose of waste more efficiently. However, the efficiency of locally available agro-residual waste in cementitious composites is not well understood. In the present investigation, the practicability of using agro-residual ash obtained from the burning of cashew nutshells on the properties of eco-friendly blended cement paste and mortars is explored. Blended cement mixtures containing cashew nutshell ash (CNSA) were prepared at five replacement levels, 5, 10, 15, 20, and 25%, relative to the weight of the cement. To understand the characteristics of CNSA, microstructure investigations such as X-ray diffraction, thermogravimetric analysis (TGA), scanning electron microscopy, and energy-dispersive spectroscopy analyses were performed. Paste properties of CNSA-based cement are observed through consistency, setting time, mini-slump flow, and expansion tests. For the CNSA-based mortars flow table, compressive strength, ultrasonic pulse velocity (UPV), electrical resistivity (ER), water absorption, bulk density, and porosity tests were performed to understand its efficiency. The strength indices of mortars were used to quantify the pozzolanic effect of CNSA. With the incorporation of CNSA, water demand increased by 57%, initial and final setting time decreased by 90% and 83%, respectively. Results showed that CNSA-based mortars absorbed more water and had higher porosity, which reduced compressive strength, UPV, and ER values. CNSA blended mortar is more suitable for applications that do not require high compressive strength. Results indicated that the compressive strength, UPV, and ER are within the limit specified. Strength indices indicated that CNSA has a positive and negative pozzolanic effect during early and later ages, respectively. Further, the sustainable assessment showed that the introduction of CNSA in mortar could substantially reduce embodied carbon, embodied energy, and strength efficiency over the control mortar. The inadequate amount of SiO2, Fe2O3, and Al2O3 in CNSA makes it an unsuitable pozzolanic material. However, it can be utilized in smaller amounts as a fractional replacement of cement and is found to be promising for specific desired properties of cement as a cost-effective accelerator.

Physical, Chemical, Thermal, and Mechanical Properties of Cotton Stalk: An Industrial Multi-purpose Cotton By-product

This study was conducted to investigate physical, chemical, thermal, and mechanical properties of cotton stalk. Cotton plant stem diameter, plant height, root spread, and plant weight were assessed and found to be significantly different for G. Arboreum and hybrid variety. The N, P, K, and S contents were 0.453, 0.227, 0.907, and 0.12% for stem; and 0.393, 0.183, 0.987, and 0.113% for root, respectively. Whereas Fe, Mn, Zn, and Cu concentrations were 205.41, 30.22, 30.64, and 20.23 ppm for stem; and 179.86, 19.00, 23.89, and 12.52 ppm, respectively, for root of cotton plant. The calorific value of cotton stem and root was 17.41 MJ.kg-1 and 17.37 MJ.kg-1, respectively. Thermal properties of cotton biomass indicated its suitability as fuel in biomass-based power plants, briquetting, and gasification. Maximum tensile strength of cotton stalk of diameters 8-14 mm ranged between 2.01-7.25 kN and 1.52-3.30 kN for stalk moisture content below and above 10% (d.b.), respectively. Maximum compressive strength of stalk diameters 8-14 mm ranged between 1.50-4.78 kN and 0.76-2.48 kN for moisture content below and above 10% (d.b.), respectively. Tensile and compressive strengths were significantly different at moisture content below and above 10 per cent. These results would help in exploring more industrial and domestic applications of cotton stalk.

Sorghum-Based Power Generation in Southern Ukraine: Energy and Environmental Assessment

An increase in energy demand, fossil fuel reserves depletion, and environmental issues are primary reasons for renewable energy use, including power generation. Bioenergy is the primary alternative to conventional hydrocarbon fuels. Biomass-based power generation is increasing due to some reasons, including a gradual decrease in the levelized cost of electricity and a reduction of carbon dioxide emissions. Sorghum is a promising energy crop for semi-arid climate zones, including southern Ukraine. It can be used for both biofuel production and power generation. However, there is a lack of methodology for energy and environmental assessments of sorghum-based power generation. Some possible technologies were analyzed. The novelty of this study is the accounting of energy consumed and carbon dioxide emissions during crop cultivation. We have determined that sorghum-based power plants can generate from 2 to 12 MWh per hectare. Their operation significantly reduces carbon dioxide emissions (from 613 to 3652 kg of carbon dioxide per hectare of sorghum silage cultivation). Sorghum-based biogas plants have energy and environmental advantages if they use co-generation technologies and utilize digestate as a biofertilizer. The utilization of digestate (obtained from silage production per hectare) substitutes up to 12.8 MWh of indirect energy. The results obtained can be used by farmers and authorities for bioenergy development.

Characteristics of Generic Dielectric Materials and Char as Bed Materials of a Dielectric Barrier Discharge Reactor under High Temperature and Wide Frequency Range

This paper investigates the characteristics of generic dielectric materials and char, which are intended to be used as the fixed bed materials of a non-thermal-plasma (NTP)-based dielectric barrier discharge (DBD) reactor. Such data are very essential when upgrading the fixed bed to a fluidised bed, which may provide further improvement in the production and quality of the producer gas. This measure would eventually cause a better producer gas and effective biomass-based power generation. Pertinent data that are currently available focus on either improving the design requirements of the producer gas or studying the impact of individual dielectric-material-specific applications to produce useful gases by decomposing the polluting gases. Considering that there has only been a meagre attempt to gather this information, this study gains its importance. In this context, the collective electrical behaviour of bed materials viz. quartz-sand, olivine, and char under ambient and higher temperatures is recorded and their frequency dependencies are analysed. First, the electrical behaviour of the chosen materials is resolved over a wide frequency range. For this purpose, two test cells, i.e., one for the ambient conditions and the other for higher temperatures, are built. Subsequently, the surface and volumetric properties of the chosen bed materials under ambient and higher temperatures are studied. As these materials are not as conductive as metal, such an approach is necessary to understand the apparent behaviour of the materials and anticipate their direct or indirect effects in the presence of non-thermal plasma. In summary, the data from the test cell under ambient and higher temperatures and the influence of materials in the dielectric barrier discharge reactor qualitatively define the material usage and may provide an opportunity to optimise their performance.

Agricultural Biomass-Based Power Generation Potential in Sri Lanka: A Techno-Economic Analysis

Worldwide energy costs have grown in recent years due to the dwindling global fossil fuel resources and the increased reliance on them for global energy production. This is a common scenario in many nations, including Sri Lanka. As a developing country, Sri Lanka should encourage the diversification of its renewable energy supplies using locally available resources. In this regard, Sri Lanka can promote the use of agricultural residues for energy generation. The present work explores the energy potential of the solid waste generated by the rice industry: rice straw (RS) and rice husk (RH). A new approach was developed using statistical data on rice production and paddy cultivation in each district of the island. The obtained data were integrated into a geographic information system (GIS) to provide geo-referenced results. A physico-chemical characterization of the RS and RH was conducted to correlate the properties of raw materials to their potential energy generation. As an energy generation technology, the grate-fired combustion boiler accompanied by steam turbine cycle (GFC/ST) was selected. Our findings show that the total energy capacity using by-products of the rice industry is estimated to be 2129.24 ktoe/year of primary energy, with a capacity of 977 Mwe, producing 5.65 TWh of electricity annually. An economic analysis shows ten districts have a high profit index (PI > 1). The districts with the highest PI values are Anuradhapura, Ampara, Polonnaruwa, and Kurunegala, with annual energy potentials of 286 ktoe, 279 ktoe, 231 ktoe, and 160 ktoe, respectively. This work aims to aid future policy decisions by identifying potential districts in which to develop infrastructure for energy generation using agricultural waste, thus reducing net greenhouse gas emissions (GHG) of Sri Lanka.

Techno-economic and environmental assessment of low carbon hybrid renewable electric systems for urban energy planning: Tehran-Iran

Tehran is one of the most populous and polluted cities in Iran with a fossil fuel-dependent economy. This paper aims to assess a techno-economic and environmental feasibility of biomass-based power plant in off-grid mode to present optimal planning for reliable electrification to Tehran. To achieve this goal, size optimization and sensitivity analysis of the proposed hybrid renewable electric system (HRES) is performed by simulating a model in HOMER software to determine the most economical and environment-friendly HRES for the studied area. The assessment criteria for selection of optimal architecture are based on the lowest of net present cost (NPC), cost of energy (COE), and carbon emission quantity (CEQ). Accordingly, HOMER proposes the seven feasible HRES that among them, the biomass generator (BG), photovoltaic (PV) and Wind turbine (WT) hybrid system including 3,181 kW PV panels, 4300 kW WT, a 5,100 kW BG, 17,035 kWh battery storage and 4,415 kW converters is the most optimum power system. Besides, the aforesaid system has COE of 0.281 $/kWh and NPC of 113 M$. Techno-economic comparison of seven systems shows that the integration of PV and WT with biomass systems could be an effective method to make a cost-optimal and reliable HRES, especially in a large scale city- for low-carbon and climate-resilient communities.