Solar Biogas Research Articles

A hybrid solar–biogas system for post-COVID-19 rural energy access

Abstract Solar home systems for rural electrification are often designed with a limited energy supply, which presents a drawback for the technology. Furthermore, uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks. Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable electricity access to underserved rural communities while achieving waste management. Therefore, this study presents a hybrid solar–biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities. A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study. The findings show that the daily household energy consumption was 6.6 kWh, equivalent to 206.40 kWh/month. A 1.2-kWp and 1.2-m3 hybrid solar–biogas system was found to adequately power the house. Financially, the total initial investment cost of the system was $5777.20 with a net present value of $6566.78, net profit of $4443.6, a payback period of 14 years and 8 months, and a levelized cost of energy of $0.21/kWh; these include a 60% initial investment and maintenance costs subsidy. Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system. The study successfully revealed the design, specifications and upscaling mechanism of the proposed hybrid solar–biogas system. More research is required to unveil the efficacy of the system, the performance gap and the perception of the technology by the beneficiaries.

Retraction Note: A systematic study on simulation and modeling of a solar biogas reactor.

Retraction Note: A systematic study on simulation and modeling of a solar biogas reactor.

A novel approach for sizing and optimization of hybrid solar-PV, biogas-generator, and batteries system for rural electrification: case study

A new approach for sizing a hybrid solar-PV-battery and biogas generator for power generation was suggested in this study, based on the variation of energy resources and the load profile. Biogas has enormous potential and numerous economic and social advantages. In this respect, the monthly solar radiation, temperature, and biogas produced from biomass resources were used as model inputs. This study considers the total annualized of the components for the feasibility analysis. HOMER Pro® software-based outcomes in the proposed methodology revealed that the proposed solar biogas hybrid system was sufficient to meet the load requirements of the village (Ain Farba village in the Hodh El Gharbi area located in the northeast of the Mauritania country) with a net present cost over the 25-year lifespan of 61,144 $ and the energy cost was determined to be 0.0473 $/kWh.

A systematic study on simulation and modeling of a solar biogas reactor.

This paper presents an overview of solar biogas simulation and optimizing performance of biogas using a renewable energy source such as solar energy. Biogas has many benefits to our environment and climate. Biogas is a renewable fuel produced by the breakdown of organic matter such as food scraps and animal waste, and we can use the biogas to generate electricity. For simulation of biogas, we used RStoic and RCSTR rectors. A feed rate of 0.333kg/day wet waste and 0.333kg/day water was used to achieve the maximum biomethane (CH4) production rate of 85.5627% at a temperature of 318.15K and 15days of batch process. In this simulation, we use solar energy to apply heat to the digester unit and provide proper preferable conditions. In this process, carbon dioxide and hydrogen sulfide are additionally generated gases. Generated biomethane (CH4) has many uses such as in biomethane filling stations. In 2015, approximately 697 biomethane (CH4) filling stations used 0.16 billion m3 of biomethane as a transportation fuel.

A Review of Solar Energy Use in Biogas Digester Heating

Abstract: Several factors affect biogas fermentation, among which the temperature fluctuation is crucial. Domestic and foreign biogas fermentation heating systems are also diverse. Among various exist methods of heating biogas fermentation, solar biogas fermentation heating systems are also diverse. The current study reviewed various solar-heating biogas fermentation systems at home and abroad, describing the principle of the solar-heating system, the collector, the heat storage material and the research and application progress. It briefly discussed its characteristics, summarising the critical technology of solar biogas heating systems.

Study on optimization method of rural integrated energy system including renewable energy

Due to the implementation of the rural revitalization strategy, the urbanization process in rural areas has been accelerated in China, as the economy has grown more rapidly and energy consumption has increased. Rural power infrastructure, however, remains inadequate and the rural power grid is relatively weak, which further exacerbates the contradiction between rural energy supply and demand. To solve these problems and achieve sustainable development, renewable energy sources should be utilized for energy supply in rural areas to reduce the demand for power from rural grids. Using this idea, this paper proposes an optimization method for an integrated energy system for rural areas that includes renewable energy sources. Firstly, a model of the output of equipment such as wind and solar biogas, as well as the model of energy storage equipment, is constructed. A portion of flexible load is considered when estimating energy consumption on the demand side. A day-ahead optimization model for rural energy systems is designed to minimize costs, which allows different energy sources to play complementary roles under the constraints of power balance, output limits, etc. The approach proposed in this paper may provide a comprehensive solution for optimizing the operation of an integrated rural energy system by improving its energy efficiency and maximizing its use of renewable energy resources. Furthermore, the article also provides specific examples of the feasibility of the method.

Solar–Biogas Microgrid: A Strategy for the Sustainable Development of Rural Communities in Pakistan

Access to uninterrupted power is not a luxury but a basic need. Rural communities living far from the national grid, particularly those in the southern region of Pakistan’s Khyber Pakhtunkhwa province, have limited access to a reliable power supply. In order to provide sustainable electricity, small-scale off-grid renewable energy systems are increasingly used for rural electrification. These systems are commonly known as stand-alone home systems or community micro-grids. This paper proposes an off-grid solar–biogas micro-grid for rural communities in the Lakki Marwat district of Khyber Pakhtunkhwa, Pakistan. The area is mainly dependent upon income from the agricultural and livestock sectors. HOMER was used to simulate the electric power system, while RET-Screen was used to analyze the economics of the system. The optimized system’s results demonstrate that the most economically and technically possible system, which produces 515 kWh and 338.50 m3 biogas daily, is made up of a 30-kW photovoltaic system coupled with a 37-kW biomass hybrid system, a 64-kWh battery storage capacity, and a 20-kW invertor. The system will meet the cooking and power needs of 900 individuals who reside in 100 homes. In addition to household users, the system will provide fixed-priced electricity to productive buildings, and free electricity to community buildings. The system will generate 1300 kg of organic fertilizer each day, which will be sold to local farmers for 50% less than what it would cost on the open market. The proposed approach is techno-economically viable based on the payback period and internal rate of return.

Integration of renewable energy into the copper mining industry: A multi-objective approach

This paper proposes a methodology for designing a solar–biogas hybrid renewable energy system considering the integration of renewable energy’s variability and its intermittency nature. It also studies for the first time the use of biogas to complement the unreliability of solar energy for a large-scale industry like mining, considering its unique characteristics. The proposed model minimizes annual costs and greenhouse gas emissions, configuring a hybrid renewable system that optimizes its usual economic benefits and defines its topology to improve the environmental impact while ensuring the energy demand. The results indicate that solar energy and biogas are attractive options to supply the electrical requirements of a copper mining process, as they bring economic and environmental benefits. However, a deeper environmental evaluation of the system is needed. The findings also show a trade-off between costs and greenhouse gas emissions; therefore, to promote the minimization of emissions in the system studied, the carbon tax price should be between 100–1,000 USD/ton CO2-eq. Finally, installing the proposed hybrid energy system could help reduce between 30% and 80% of the emissions compared to the actual scenario, and it could reduce around 50% of the total emissions in the next 30 years.

Experimental conception and thermo-energetic analysis of a solar biogas production system

Solar biogas system production offers the possibility to simultaneously produce heat, electricity and to treat waste products as well as to reduce greenhouse gas emissions in the industrial sector. In this paper, we report on the development of an experimental solar biogas prototype to valorize the biomass generated by the Moroccan paper industry in order to reduce its carbon footprint. This paper presents an integrated solution to an environmental and energy problem of the companies that generate wet waste biomass. The current new prototype consists of a biogas production system using liquid biomass, a solar installation, and thermodynamic storage derived from a heat pump. Energy balances carried out show that the solar system can reach a thermal efficiency of 70%; the thermal losses of the system are around 53% for the biogas system and 22.6% for the storage and piping system. Further, the results found indicate the average heat demand of the digester reactor is 302 kWh per month, the solar system produced 284 kWh per month (94%) in worth case, which means the solar system is the main source energy and the system solar biogas is a self-energy system. Besides, it was found that the pilot solar biogas system produces about 1100 L of biogas, the analysis of biogas produced prove that it contains 74% of CH4 (814 L) and processes about 3000 L of industrial biomass daily, the biogas conversion efficiency of the whole system is 42%. The economic potential of the current solar biogas system in terms of electricity savings reached 2 MWh per month. The life cycle savings of the current solar system instead of purchasing electricity to meet the energy needs of the biogas process is approximately $4687. Annual emissions of (CO2), carbon monoxide (CO), and nitrogen oxides (NOx) are reduced by 69%, 71%, and 70% respectively. Upscaling the current prototype system to 700 m3 (reactor volume) for the case study of cardboard company industry, shows that the yearly bio-methane (CH4) production is around 52,836 m3 per year, which represent 64% of the total fuel consumption for the current case of cardboard recycling and packaging company.

Performance Analysis of a Solar–Biogas Hybrid Micro Gas Turbine for Power Generation

Abstract A performance assessment was conducted for a solar–biogas hybrid micro gas turbine integrated with a solar power tower technology. The considered system is a solar central receiver integrated with a micro gas turbine hybrid with biogas fuel as a backup. The Brayton cycle is designed to receive a dual integrated heat source input that works alternatively to keep the heat input to the system continuous. The study considered several key performance parameters including meteorological condition effects, recuperator existence and effectiveness, solar share, and gas turbine components performance. This study shows a significant reduction in CO2 emissions due to the utilization and hybridization of the renewable energies, solar, and biogas. The study reveals that the solar–biogas hybrid micro gas turbine for 100-kW power production has a CO2 emission less than a conventional fossil fuel gas turbine. Finally, the study shows that the method of power generation hybridization for solar and biogas gas turbines is a promising technique that leads to fuel-savings and lower CO2 emissions.

Powering communities using hybrid solar–biogas in Ghana, a feasibility study

Abstract This study ascertained the possible use of a hybrid power system as an alternative sustainable energy source through hybridization of biogas and solar Photovoltaic (PV) system, in Ghana. A simple Multi Criteria Analysis (MCA) method was used in selecting the three (3) representative renewable energy (RE) businesses based on registered energy projects by the Energy Commission (EC) of Ghana. The analysis compared the 3 business sites with regard to generating power: (1) feeding to the national grid (FiT) (2) for self-consumption (prosumers) and (3) for agricultural use (through irrigation). The result showed that hybridization of solar and waste to energy systems is feasible with the use of manual change over for small and non-critical applications and smart energy control systems for community based and critical applications. It also revealed that integrating solar PV system with an existing biogas plant is both feasible in terms of technical and cost-effective wise to boost the power production for daily usage. However, the hybrid power system would be viable at an operational cost of 40% revenue and at a FiT unit price of $0.17/kWh. Further, the study found that adding a biogas plant to an existing solar PV plant would be more expensive. In all, solar–biogas hybrid power system has a great future through its operational flexibility of mitigating potential shortfall in power, both seasonally and diurnally, and assuring a more secure and efficient supply of energy for communities both grid and non-grid connected. The use of energy from renewable sources, by its efficiency and reduction of carbon footprints, will contribute to the attainment of the core objectives of some key global protection and socio-economic development initiatives/programs including Sustainable Development Goals (SDG) - namely SDGs 7,13.

A Temperature Gradient based Harvesting of Solar Energy using a TEG Device

There has been an increasing demand for energy since the last decade especially due to the rapid depletion of non-renewable sources of energy. Technological advancements in the area of renewable sources of energy has been ever since increasing utilizing wind, solar bio gas sources of energy for power generation. A more recent research interest is towards tapping of solar energy from saline lakes or ponds which are manmade. It proves to be a cost effective strategy over the solar radiation harvesting using solar cells for small power generation system. Research analysis and contributions have reported temperatures ranging from 700–800C being trapped in the saline solutions of the lake which could be effectively utilized for energy harvesting. The proposed work aims to derive energy based on the concept of thermo electric devices which constitute a current flow due to differences in the temperature gradient of the saline solution. Salinity-gradient solar ponds can collect and store solar heat at temperatures up to 80C. As a result, these water bodies act as a renewable source of low grade heat which can be utilized for heating and power generation applications. In addition to utilizing thermo electric modules as power generators in this paper, A potential advantage of such a system is its ability to continue to provide useful power output at night time or on cloudy days because of the thermal storage capability of the solar pond.

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.

Solar Biogas Digester and Wetland-Pond System for Rural Wastewater Treatment

Solar biogas digester and wetland-pond system treated the wastewater for the rural about 60 families. The system comprised a solar anaerobic baffle digester, an anaerobic filter, a subsurface vertical flow wetland, and an eco pond. The four units were connected in series. The solar digester and the filter produced enough biogas evenly in whole year and provided 80-91% total suspended solids (TSS) removal. The wetland-pond developed aquatic crops, fisheries and waterfowl aquaculture. In this artificial ecosystem, bacterial oxidization, algae photosynthesis and food web degradation greatly reduced COD, BOD5, TN, NH4-N, TP, and pH of water.

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.