Biogas Generator Research Articles

Analyzing of a Photovoltaic/Wind/Biogas/Pumped-Hydro Off-Grid Hybrid System for Rural Electrification in Sub-Saharan Africa—Case Study of Djoundé in Northern Cameroon

Traditional electrification methods, including grid extension and stand-alone diesel generators, have shown limitations to sustainability in the face of rural electrification challenges in sub-Saharan Africa (SSA), where electrification rates remain the lowest in the world. This study aims at performing a techno-economic analysis and optimization of a pumped-hydro energy storage based 100%-renewable off-grid hybrid energy system for the electrification of Djoundé, which is a small village in northern Cameroon. Hybrid Optimization of Multiple Energy Resources (HOMER) software was used as an analysis tool, and the resulting optimal system architecture included an 81.8 kW PV array and a 15 kW biogas generator, with a cost of energy (COE) and total net present cost (NPC) of €0.256/kWh and €370,426, respectively. The system showed promise given the upcoming decrease in installation cost of photovoltaic systems. It will be viable in parts of SSA region but, significant investment subsidies will be needed elsewhere. The originality of this study can be emphasized in three points: (1) the modelling with the recently introduced pumped-hydro component of HOMER; (2) broadening sensitivity analysis applications to address practical issues related to hybrid renewable energy systems (HRES); and, (3) consideration of the agricultural sector and seasonal variation in the assessment of the electricity demand in an area of SSA.

Expeditious frequency control of solar photovoltaic/biogas/biodiesel generator based isolated renewable microgrid using grasshopper optimisation algorithm

This work endeavours to propose an approximate mathematical model of a community based renewable microgrid with solar photovoltaic, biogas and biodiesel generators including battery storage for load frequency studies. It becomes a great challenge to coordinate between generation and load demand of the microgrid as the renewable sources are highly unpredictable and nature dependent. To overcome this issue, the responses of the system are studied under different real-world scenarios of renewable source availabilities and load variations with a maiden approach towards optimising the controller gains using a recent grasshopper optimisation algorithm (GOA) for efficient frequency control. The frequency responses of proposed microgrid are compared with different conventional controllers and some popular optimisation algorithms using MATLAB/Simulink. Finally, proportional-integral-derivative controller with GOA is preferred for the case studies under four cases of source variations with step load perturbation and one case of simultaneous source and load variations. The results of all these five scenarios are found satisfactory in terms of frequency responses and reported in the work.

Comparative analysis and performance of load bearing characteristics of biogas and gasoline-fuelled electric generator

ABSTRACT This research demonstrates a simplified purification of biogas from hybrid waste and conversion of a single cylinder spark ignition engine to use biogas. The scrubbed gas obtained showed 95% methane enriched biogas. The carburettor of the gasoline engine was modified with a tri-fuel carburettor to suit the input specimen fuel fed to the modified 2.5 kVA, 230 V, and 50 Hz reciprocating engine to generate power. Results showed that 1 kg of compressed biogas ran for 46 min with a load capacity of 1800 W on the 2.5 kVA modified generator, while a litre of gasoline ran for 72 min under the same loading capacity. A comparative assessment of the load bearing characteristics was conducted. Load condition exceeding 1000 W resulted in a voltage output drop of 14.25% on biogas while a small change in voltage of 0.06% occurred for loading conditions between 100 and 1000 W. There was 8.5% decrease in engine speed while operating on biogas with little or no change on gasoline. Maximum torque of 5 and 3.5 Nm at 1800 W electric loading was experienced for gasoline and biogas. Finally, the BSFC for gasoline and biogas at 15% loading condition was maximum at 2000 and 2400 kg/kWh, respectively.

PEMBUATAN ALAT PENGHASIL BIOGAS SEDERHANA DI KAMPUNG HAWAI KABUPATEN JAYAPURA

Biogas is a gas produced from the process of decomposition of organic materials by microorganisms in rare oxygen (anaerobic) conditions. Biogas component: ± 60% CH (methane), ± 38% CO (carbon dioxide), ± 2% N2 , O2 , H2 , and H2 S2. Biogas materials in this service comes from cow dung. Cow manure is a substrate that is considered most suitable as a source of biogas, because the substrate already contains methane as source of energy. In addition to cattle dung biogas can also reduce environmental pollution because it produced a more environmentally friendly energy source. In Kampung Hawai, Jayapura Regency, some of people have been doing cattle ranching activities. The waste in the form of fresh cow dung has not been utilized for the manufacture of biogas as an alternative energy source.The purpose of this devotional activity was to utilize fresh cow dung as a biogas energy source by creating simple biogas generator tools with cheap and easy equipment. The method used with the ratio of cow dung and water, 1:1 and also the addition of EM4 (Effective microorganisms) in the mixture of 5%, 7.5%, 10%; and 12.5% with fixed volume in the digester. The results of this activity obtained biogas which can be made by using a simple tool with respect to the ratio of mixture cow dung and water. Addition of EM4 affects the fermentation reaction in the digester to produce biogas. The highest biogas production was obtained in the addition of EM4 by 10% with the highest produced pressure and obtained quite significantly starting on the 12th day. The cattle ranchers at this location was interested in this devotion activity and will continue to apply the technology of making biogas that has been informed and understood. Keywords: Biogas, Cow Manure, EM4, Pressure

Hierarchical and decentralized optimization method based on multi-agent system for multiple AC/DC hybrid microgrids

AC/DC hybrid microgrids (MGs) have been developed rapidly in recent years due to their efficient integration and management of large-scale distributed energy resources. How to achieve the optimal operation and coordinated control of AC/DC hybrid MGs has become crucial. A multi-agent system (MAS) based hierarchical and decentralized method for coordination operation of multiple AC/DC hybrid MGs is proposed. First, a structure of AC/DC hybrid MGs including wind turbines, photovoltaics, micro-hydro, and biogas generators is designed, which aims at reducing the power conversion loss. Second, a three-level MAS including distribution network (DN) level, MG level, and distributed generation (DG) level is presented. At the DG level, the DG agents obtain the optimal results from the MG agent. At the MG level, the independent optimization is implemented based on the mixed integer linear programming, and the consensus algorithm is utilized to realize the coordination of MG with adjacent MGs through the communication among MG agents when there is imbalance power. At the DN level, the DN agent performs power exchange with AC/DC hybrid MGs to balance the load demand when needed. Finally, the distributed energy management platform is developed by the Java Agent Development Framework platform to simulate the optimal operation of AC/DC hybrid MGs. The results show the rationality and availability of the proposed optimization method.

Feasibility assessment & design of hybrid renewable energy based electric vehicle charging station in Bangladesh

The rapid increase in electric vehicle (EV) in Bangladesh requires more energy to run these vehicles. Moreover, the transportation sector produces Green House Gas (GHG) especially CO2 emissions. Due to the excess power needed to recharge these EVs, the national grid has to supply more than 500 MW daily. This paper proposes an Electric Vehicle Charging Station (EVCS) based on solar and biogas to reduce the burden on the national grid. The proposed EVCS integrates a combination of a solar PV module (10 kW), three biogas generators (10 kW), 25 lead acid batteries (each 100 Ah), a converter (10 kW) and charging assemblies. This paper analyzes the technical, economic and environmental feasibility of the proposed EVCS using the Hybrid Optimization of Multiple Energy Renewables (HOMER) Pro software. This configuration estimates a Cost of Energy (COE) of $0.1302/kWh, total net present cost (NPC) of $56,202 and operating cost of $2540. In addition, the proposed model reduces the CO2 emissions by 34.68% compared to a conventional grid-based charging station. The designed EVCS saves approximately $12–$18 per month to recharge an EV which increases the socio-economic standard of EV owner.

A techno-economic feasibility of a stand-alone hybrid power generation for remote area application in Bangladesh

A techno-economic feasibility of a stand-alone hybrid power generation for a remote community in Bangladesh is carried out in this study. The proposed system integrates a combination of biogas generator, PV modules, diesel generators, wind turbines, and lead acid battery to meet the electric load requirements using Hybrid Optimization Model for Electric Renewables (HOMER) software tool. The designated system would satisfy the energy requirements of 248 kWh/day primary load with 44.41 kW peak load. The optimized hybrid system consists of a biogas generator (9 kW), PV modules (10 kW), 2 diesel generators (10 kW each), 72 batteries (390Ah each), and 15 kW inverters. This configuration gives the COE of $0.28/kWh and total Net Present Cost (NPC) of $612280 with a renewable fraction of 60%. Additionally, the system has potential benefit to reduce CO2 emission by nearly 59.6% per year as compared to a diesel-based system and by 40.5% compared to the grid electricity. Furthermore, the results also indicate that it is fairly impossible to reach grid electricity price parity even with full government support for the project capital cost. However, the proposed system is found as an economical option than supplying electricity to the remote community with solar home systems (SHSs).

Potential and feasibility study of standalone solar PV/wind/biogas and biodiesel hybrid electric supply system in Ethiopia

The main focus of this study is renewable energy resource assessment and feasibility study to generate electricity for the rural community from solar PV, wind turbine, biogas and biodiesel generator. To model and analyse the feasibility of the hybrid system HOMER was chosen. Grid comparison against the hybrid system was done for cost benefit analysis. The optimisation result of the simulation demonstrates that the best optimal hybrid system consists of solar photo voltaic, wind turbine, biogas generator, biodiesel generator, converter and battery under load following system control strategy. This system has initial capital cost of $335,468, net present cost of $837,915, levelised cost of energy of $0.239/kWh. The total capital cost of grid extension was determined as $147,752, and its operation and maintenance cost is 267$/km/yr.

Potential and feasibility study of standalone solar PV/wind/biogas and biodiesel hybrid electric supply system in Ethiopia

The main focus of this study is renewable energy resource assessment and feasibility study to generate electricity for the rural community from solar PV, wind turbine, biogas and biodiesel generator. To model and analyse the feasibility of the hybrid system HOMER was chosen. Grid comparison against the hybrid system was done for cost benefit analysis. The optimisation result of the simulation demonstrates that the best optimal hybrid system consists of solar photo voltaic, wind turbine, biogas generator, biodiesel generator, converter and battery under load following system control strategy. This system has initial capital cost of $335,468, net present cost of $837,915, levelised cost of energy of $0.239/kWh. The total capital cost of grid extension was determined as $147,752, and its operation and maintenance cost is 267$/km/yr.

Design of Solar-Biomass Hybrid Microgrid System in Sharjah

Abstract Micropower optimization model is used in this study to design renewable energy-based micro grid system: solar-biomass hybrid system for the electrification of the city of Sharjah. The principal objective is to explore the available renewable resources in Sharjah and to determine the optimal configuration to meet the desired electric loads of the city. The hybrid system consists of electrical loads, solar resources, biomass resources, and system components such as solar photovoltaic, biogas generators, biomass power, battery and converters. Input information on the primary loads, solar and biomass resource availability, technology options, components cost, constraints, and controls are determined. Hourly simulations with sensitive analysis were performed to calculate the energy to and from each component to design the most favorable renewable energy-based system. The optimized results of the alternative renewable energy-based hybrid systems with different levels of contributions by renewable resources are presented in this paper taking into account the technology costs, energy resource availability and the efficiency of the renewable energy system.

Techno-economic analysis of a PV/biomass/fuel cell energy system considering different fuel cell system initial capital costs

Despite many investigations on photovoltaic (PV)/wind/fuel cell (FC) systems, the integration of FC with biomass energy, biogas generator (BG), is rarely found. In this paper, a hybrid PV/BG/FC power generation system is modeled and designed for electrification to a stand-alone region in Iran. The configuration of the proposed hybrid system is optimally determined with respect to different fuel cell system initial capital costs. For this aim, the fuel cell system initial capital cost is varied from 2000$/kW to 4000$/kW and the amount of the FC generation from the total generation of the hybrid system is evaluated by considering loss of power supply probability (LPSP). From the results it is seen that in the optimized PV/BG/FC system and at LPSP=2%, by decrease of the fuel cell system initial capital cost from 4000$/kW to 2000$/kW, the rated power of fuel cell system increases from 33.34kW to 213.54kW, the rated power of the biomass system decreases from 145.00kW to 0.11kW and total area occupied by the photovoltaic system decreases from 373.40m2 to 0.96m2.

Modeling of an Optimized Hybrid Energy System for Kutubdia Island, Bangladesh

This paper presents an optimized energy system model for a small locality in Kutubdia Island, Bangladesh at latitude of 21.82 °N, longitude of 91.86 °E. This isolated island is located at the southern coast of Bangladesh, separated from the main land by the Kutubdia channel. At present, grid connection from the mainland is not present and is not planned in the near future. The proposed energy system comprises Solar PV, Wind turbines, Biogas generators for power generation whereas a diesel generator has been used as backup power supply and batteries have been considered to facilitate energy storage. Hybrid Optimization Model for Electric Renewable (HOMER) has been used to obtain an optimized system comprising all the renewable energy resources present. The designed energy system consists of 28 kW Solar PV panels, 30 kW Wind Turbines, 8 kW Biogas Generator, 9 kW Diesel Generator. The system generates electricity with a renewable fraction of 97%. The cost of electricity has been estimated as US$ 0.42/kWh considering 10% Rate of Return with an initial capital cost of US$ 199,541.

Electricity supply characteristics of a biogas power generation system adjacent to a livestock barn

In order to consider the potential for electricity supply from a biogas power generation system (BGP) located adjacent to a livestock barn, the power balance was determined by using both simulation and actual measurement. Examination of power balances at the barn and the BGP showed that a certain amount of electricity for supply could be secured based on load leveling in both tie-stall barns and free-stall barns. BGPs are a viable renewable energy (RE) power source that can produce enough electricity for system operation and maintenance as well as a significant surplus of supply for power companies and other users. BGPs have the potential to allow output control appropriate for the relevant amount of gas storage. Further, output control based on the use of a gas holder in combination with changes in the number of biogas generators could allow more efficient usage of biogas. Specifically, the range of power output adjustment can be widened through parallel operation of several biogas generators, instead of a single generator. In other words, one biogas generator uses a constant power supply, and the other uses it to control the output for the related amount of gas storage. In this way, the possibility of achieving a constant electricity output through biogas power generation system and a regulated power supply was demonstrated.

Stand-alone hybrid energy system for sustainable development in rural India

Renewable energy system such as solar, wind, small hydro and biogas generators can be used successfully in rural off-grid locations where grid connection is not possible. The main objectives of this study are to examine which configuration is the most cost-effective for the village. One renewable energy model has been developed for supplying electric power for 124 rural households of an off-grid rural village in eastern India. The load demand of the village was determined by the survey work, and the loads were divided into three sub-heads such as primary load I, primary load II and deferred load. Locally available energy sources such as solar radiation and biogas derived from cow dung and kitchen wastes were used as sensitivity variables. This study is unique as it has not considered any diesel generator for supplying unmet electricity to the households; rather it completely depends on locally available renewable resources. Here in this paper, two different models were taken and their cost and environmental benefit were discussed and compared. The net present cost, levelised cost of energy and operating cost for various configurations of models were determined. The minimum cost of energy of $0.476/kWh with lowest net present cost of $386,971 and lowest operating cost ($21,025/year) was found with stand-alone solar–biogas hybrid system.

A software tool for capacity optimization of hybrid power systems including renewable energy technologies based on a hybrid genetic algorithm—tabu search optimization methodology

This paper presents a software tool that has been developed for optimal configuration of hybrid power systems. These systems can be either interconnected to the main power grid or operated autonomously, and may contain a variety of components, including dispatchable generators (e.g., diesel generators, microturbines, biogas generators), non-dispatchable renewable energy technologies (e.g., wind turbines, photovoltaics), batteries, converters and dump loads. A software tool that optimizes such systems has been developed in MATLAB, using a combination of genetic algorithms and tabu search. The optimal configuration is expressed in terms of minimum cost of electricity (in €/kWh), taking into account operational and component size constraints. The needed input includes weather data (e.g., solar, wind, and temperature time-series), load data, system components data, and general parameters (e.g., project lifetime, discount rate). As a case study, in this paper the tool is used for evaluating an autonomous hybrid power system that includes renewable energy technologies in Chania region, Crete. Moreover, the performance of the tool is investigated for seven additional scenarios of the case study, via sensitivity analysis, studying the effect on the results of the uncertainty of weather and cost data.

Modeling and Optimization of Decentralized Microgrid System for St. Martin’s Island in Bangladesh

St. Martin’s Island is a little Island in the Bay of Bengal about 9 km far from the main land of Bangladesh. Nearly 5000 residents live there and fishing is their primary livelihood and as a tourist spot there are many lodges and rest houses. Since the Island is far away from the convenential national grid connection is almost unachievable even in future as a result of its geographical location. Locally installed diesel generator is used to provide electricity to inhabitants is established by power development board of Bangladesh but now it is not in operation. In this paper, an effort has been made to model a microgrid by means of hybrid electricity generation system for a small society of the Island. This system incorporates an arrangement of solar PV, wind turbine, storage battery, biogas and diesel generator. HOMER is software for optimization of renewable based amalgamative distributed generation systems has been used to find out the preeminent technical effective renewable based energy efficient system for 650 family units. Sensitivity analysis is also completed to perceive the impact of solar insolation, PV investment cost and wind speed and diesel fuel price on the optimum result. During peak load the convenential diesel generator is switched on after covering demand by renewable source. The results of the propose system shows that due to emphasize on renewable energy sources the greenhouse gas can be minimized and this proposed system produces 12000kg of carbon-dioxide, 32.2kg of carbon-monoxide and 23.8kg of sulfur dioxide per year which is comparatively less than the average produced greenhouse. This system produces carbon-dioxide emission of approximately12000kg per year whereas 700kW diesel generator produces 413kg per hour.

ASSESSMENT OF THE COMPOSITION AND THE VOLUME OF BIOGAS LIBERATION FROM AGRICULTURAL WASTES

Study was conducted in the Faculty of Agriculture, University of Ruhuna, Mapalana toassess the composition and the volume of biogas liberation pattern from differentagricultural raw materials. In the Sri Lankan batch type biogas generator (volume 6m first batch of straw (lOOOkg)was filled in September 1999 and second and third batch in October 2000, April 2001respectively. It was revealed that average gas production from the digester was 1.0 m3/daywith a peak value of 1.8m3/day. Total gas production during four and half month period ofdigestion was 166.85 m3. The maximum average methane percentage and the average lagphase during the digestion were 50% and 20 days respectively. In order to assess the biogas liberation pattern and composiuon of each material, alaboratory test unit was designed using a 20 L plastic gallon as the digester andexperiment was conducted using straw, cow dung and market garbage (vegetable) as rawmaterials. Gas volumes, pH value of slurry and methane percentage were measured whilemaintaining the temperature between 35°C-37°C using electric bulbs. N,P,K compositions, CIN ratio and dry matter percentages of different raw materials wereanalyzed. Total biogas liberated per unit weight of dry matter was 8.15 L, 58.7 Land15.797L for dung, vegetable and straw respectively. The duration of digestion period was55-60 days. Average methane percentages of the liberated gases were 53%, 54% and 50%for dung, vegetable and straw respectively. It was revealed that market garbage had thehighest digestibility value, which had the highest gas production with high methanepercentage.

Optimal sizing of a solar–biogas-based cooking system for a cluster of villages

Energy supplies particularly in remote and far-flung rural areas are in pathetic situation. Leave aside other needs, most of the rural communities still use wood as a source of energy for cooking. Burning of wood is not only an inefficient method, but also hazardousness for the person working on the stove. People have been working for cleaner and efficient means of cooking for decades. Solar cooker- and biogas-based cook stoves are two of the successfully implemented technologies in this area. Although solar cooker requires no maintenance, the initial investment is quite high for a cluster of villages. In addition to this, the intermittency involved in solar energy makes this an unreliable source.In this paper, a cluster of villages of Narendra Nagar block of Tehri Garhwal district of Uttarakhand, India, has been studied in terms of their thermal requirements. The potential of solar energy and biomass energy has been estimated. An integrated solar–biogas system has been proposed to satisfy this cooking demand. To obtain the optimal sizes of solar cooker and biogas generator, MATLAB codes have been developed. It was found that this system is more economical and much reliable than the other two cases.

Pilot-scale chemical–biological system for efficient H2S removal from biogas

A pilot-scale chemical–biological process was performed efficiently to remove corrosive H2S from biogas. Consecutive 356-d livestock biogas purification was conducted at various H2S loading rates. The average inlet H2S concentration was 3542ppm, and a removal efficiency of 95% was achieved with gas retention time of 288s. This system showed robust performance during operation with stable parameters. Purified biogas with an average of 59% CH4 was collected for power production. Moreover, 28.3kWh of power was produced by using a 30kW biogas generator under 300LPM biogas flow rate. During the 30-d shut down test, the jarosite formation resulted in pH decrease and appearance of Leptospirillum sp. and Sulfobacillus sp. in the bioreactor. However, the cell density of the inoculated Acidithiobacillus ferrooxidans was maintained above 5×107CFU/g-AC during long-term operation. Thus, given the successful H2S elimination, the chemical–biological process is a feasible system for biogas purification.

Biogas Generator Temperature Monitoring Based on Time Series Algorithm

The biogas generator temperature control is very important to the temperature of the biogas generator for effective control, So the temperature must be monitored. Pre-estimated by measuring the temperature and fast temperature control is the most effective means. In this paper, using time series analysis method, we establish three prediction models, which are namely autoregressive model, moving average model, hybrid model. By comparison of three models, the final choice to predict the temperature of the biogas generator is mixed model analysis of time series. The test error is very small, indicating that the method has some practical value.