Design of 3 kW integrated power generation system from solar and biogas

Energy/Power is an important element of social and economic development. Without availability of energy at a reasonable price, there is little prospect of developing the country's economy and people's living conditions. A quarter of Pakistani population have no access to electricity, and currently a shortage of 5.0–7.0 GW power supply causes load shedding/blackout problems. In Pakistan, most of the power is generated from non-renewable sources like natural gas etc. Pakistan receives almost 15.525 × 10¹⁴ kW-hour of solar energy per year and sunshine duration is normally 8.0–10.0 h per day. Animal/farm wastes are readily available in Pakistan. Residues from these sources produce 103.0 billion m³ of biogas per year that is equivalent to 63.20 TWh. The objective of this study is energy production by using easily available indigenous resources. In this study a 3.0 kW integrated solar/biogas power generation system consist of 2.84 kW solar system and 4.0 m³ biogas system is designed and installed. This paper also present simulation model of system. A hybrid inverter is used to convert DC power of photovoltaic modules and the battery bank in to AC power and combines with the output power of biogas generator. Performance of the hybrid system are analysed from May 1, 2018 to June 15, 2018. During the test maximum power produce by the integrated system is 1.10 kW in morning, 2.14 kW in noon and 1.16 kW in afternoon.     

Domestic integration of micro-renewable electricity generation in Ireland – The current status and economic reality

The utilisation of renewable energy resources for power generation is extremely important for Ireland due to the lack of indigenous fossil fuel resources. A micro-wind turbine is by far the most commonly used grid-connected micro-renewable electricity generation system for domestic applications in Ireland, followed by solar PV. Unfortunately, neither a single micro-wind turbine nor a single solar PV system can provide a continuous power supply due to variations in weather and climate conditions. The coupling of these two systems however can improve the power supply reliability by using the complementary characteristics of wind and solar energy. In this paper, a micro-renewable electricity-generation-system integration technique, tailored for applications in Ireland but generally applicable, is presented. Net present value is the parameter used to identify the optimal system. The optimal system can be a mono system, formed from a single micro-wind turbine or a single solar PV system, or a hybrid system formed from a combination of both. A renewable energy requirement is a constraint used in the integration to eliminate systems that cannot provide sufficient energy from renewable energy resources. The integration technique is applied to find the optimal system, under current Irish conditions, that can be formed from six sample micro-wind turbines and/or solar PV systems assembled from three sample solar PV modules. The analyses show that, with a 50% renewable energy requirement, the optimal system is a mono system containing a 2.4 kW micro-wind turbine; however, critically, the system is not economically viable. Four parameter studies assessing the effect of household electrical load, imported electricity price, exported electricity tariff and wind speed have also been conducted. From these studies it is seen that the most effective way to improve the financial performance of all systems is to offer a higher exported electricity tariff; installing a mono/hybrid system containing a micro-wind turbine in a location with a good wind resource can also have a significant effect.     

A mobile off-grid platform powered with photovoltaic/wind/battery/fuel cell hybrid power systems

Cross utilization of photovoltaic/wind/battery/fuel cell hybrid-power-system has been demonstrated to power an off-grid mobile living space. This concept shows that different renewable energy sources can be used simultaneously to power off-grid applications together with battery and hydrogen energy storage options. Photovoltaic (PV) and wind energy are used as primary sources and a fuel cell is used as backup power. A total of 2.7 kW energy production (wind and PV panels) along with 1.2 kW fuel cell power is supported with 17.2 kWh battery and 15 kWh hydrogen storage capacities. Supply/demand scenarios are prepared based on wind and solar data for Istanbul. Primary energy sources supply load and charge batteries. When there is energy excess, it is used to electrolyse water for hydrogen production, which in turn can either be used to power fuel cells or burnt as fuel by the hydrogen cooker. Power-to-gas and gas-to-power schemes are effectively utilized and shown in this study. Power demand by the installed equipment is supplied by batteries if no renewable energy is available. If there is high demand beyond battery capacity, fuel cell supplies energy in parallel. Automatic and manual controllable hydraulic systems are designed and installed to increase the photovoltaic efficiency by vertical axis control, to lift up & down wind turbine and to prevent vibrations on vehicle. Automatic control, data acquisition, monitoring, telemetry hardware and software are established. In order to increase public awareness of renewable energy sources and its applications, system has been demonstrated in various exhibitions, conferences, energy forums, universities, governmental and nongovernmental organizations in Turkey, Austria, United Arab Emirates and Romania.     

Development of isolated energy systems based on renewable energy sources and hydrogen storage

For the development of the energy infrastructure of remote isolated consumers, an expedient solution is the creation of a modular hybrid energy system based on renewable energy sources, which will save tens of billions of rubles a year by saving expensive diesel fuel. Taking into account the high wind energy resource in these territories, the use of wind power plants as part of that system is justified. The article discusses the methodology for substantiating the parameters and modes of operation of an autonomous wind-diesel power complex based on the territorial-power classification of power supply systems and a 4-level methodology for optimizing parameters, an example of upgrading an existing diesel power plant in the Arkhangelsk region is given. The existing diesel units with a capacity of 1300 kW were replaced by a modular wind-diesel power system with a high renewable penetration level (58%) with four wind turbines with a capacity of 200 kW and a storage system with a capacity of 65 kWh. This made it possible to achieve a diesel fuel replacement share of 232 000 L per year, which in monetary terms in 2021 prices is 25 million rubles per year. As a promising direction, a variant of the territorial development of the energy sector of the Leshukonsky district of the Arkhangelsk region based on wind energy with the possibility of producing up to 100 tons of “green” hydrogen annually is considered. Various options for reducing harmful emissions in the region were considered, the maximum use of local resources allows saving up to 22 000 tons of CO_2e per year.     

Integration of wind turbine with heliostat based CSP/CPVT system for hydrogen production and polygeneration: A thermodynamic comparison

In this study, two wind-solar-based polygeneration systems namely CES-1 and CES-2 are developed, modeled, and analyzed thermodynamically. CES-1 hybridizes a heliostat based CSP system with wind turbines while CES-2 integrates heliostat-based CPVT with wind turbines. This study aims to compare the production and thermodynamics performance of two heliostat based concentrated solar power technologies when hybridized with wind turbines. The systems have been modeled to produce, freshwater, hot water, electricity, hydrogen, and cooling with different cycles/subsystems. While the overall objective of the study is to model two polygeneration systems with improved energy and exergy performances, the performances of two solar technologies are compared. The wind turbine system integrated with the comprehensive energy systems will produce 1.14 MW of electricity and it has 72.2% energy and exergy efficiency. Also, based on the same solar energy input, the performance of the heliostat integrated CPVT system (CES-2) is found to be better than that of the CSP based system (CES-1). The polygeneration thermal and exergy efficiencies for the two systems respectively are 48.08% and 31.67% for CES-1; 59.7% and 43.91% for CES-2. Also, the electric power produced by CES-2 is 280 kW higher in comparison to CES-1.     

Techno-economic analysis and optimization of a proposed solar-wind-driven multigeneration system; case study of Iran

This paper performs a thermo-economic assessment of a multi-generation system based on solar and wind renewable energy sources. This system works to generate power, freshwater, and hydrogen, which consists of the following parts: the solar collectors, Steam Rankine subsystem, Organic Rankine subsystem, desalination part, and hydrogen production and compression unit. Initially, the effects of variables including reference temperature, solar radiation intensity, wind speed, and solar cycle mass flow rate, which depend on weather conditions and affect the performance of the integrated system, were investigated. The thermodynamic analysis results showed that the overall study's exergy efficiency, the rate of hydrogen and freshwater production, and total cost rate are 33.3%, 7.92 kg/h, 1.6398 kg/s, and 61.28 $/h, respectively. Also, the net power generation rate in the Steam and Organic Rankine subsystems and wind turbines are 315 kW, 326.52 kW, and 226 kW, respectively. The main goal of this study is to minimize the total cost rate of the system and maximize the exergy efficiency and hydrogen and freshwater production rate of the total system. The results of optimization showed that the exergy efficiency value improved by 20.7%, the hydrogen production rate increased by 1%, and the total cost rate value declined by 2%. Moreover, the optimum point is similar to a region in Hormozgan province, Iran. So, this region is proposed for building the power plant.     

Optimisation of solar-hydrogen power system for household applications

A numerical method was developed for optimising solar–hydrogen energy system to supply renewable energy for typical household connected with the grid. The considered case study involved household located in Diyala Governorate, Iraq. The solar–hydrogen energy system was designed to meet the desired electrical load and increase the renewable energy fraction using optimum fuel cell capacity. The simulation process was conducted by MATLAB based on the experimental data for electrical load, solar radiation and ambient temperature at a 1-min time-step resolution. Results demonstrated that the optimum fuel cell capacity was approximately 2.25 kW at 1.8 kW photovoltaic power system based on the average of the daily energy consumption of 6.8 kWh. The yearly renewable energy fraction increased from 31.82% to 95.82% due to the integration of the photovoltaic system with a 2.25 kW fuel cell used as a robust energy storage unit. In addition, the energy supply, which is the economic aspect for the optimum system, levelised electricity cost by approximately $0.195/kWh. The obtained results showed that the proposed numerical analysis methodology offers a distinctive property that can be used effectively to optimise hybrid renewable energy systems.     

Renewable energy systems based on hydrogen for remote applications

An integrated renewable energy (RE) system for powering remote communication stations and based on hydrogen is described. The system is based on the production of hydrogen by electrolysis whereby the electricity is generated by a 10 kW wind turbine (WT) and 1 kW photovoltaic (PV) array. When available, the excess power from the RE sources is used to produce and store hydrogen. When not enough energy is produced from the RE sources, the electricity is then regenerated from the stored hydrogen via a 5 kW proton exchange membrane fuel cell system. Overview results on the performances of the WT, PV, and fuel cells system are presented.     

Off-grid hybrid renewable energy system with hydrogen storage for South African rural community health clinic

Most inhabitants of rural communities in Africa lack access to clean and reliable electricity. This has deprived the rural dwellers access to modern healthcare delivery. In this paper, an off-grid renewable energy system consisting of solar PV and wind turbine with hydrogen storage scheme has been explored to meet the electrical energy demands of a health clinic. The health clinic proposed is a group II with 10 beds located in a typical village in South Africa. First, the wind and solar energy resources of the village were analysed. Thereafter, the microgrid architecture that would meet the energy demand of the clinic (18.67 kWh/day) was determined. Some of the key results reveal that the average annual wind speed at 60 m anemometer height and solar irradiation of the village are 7.9 m/s and 4.779 kWh/m²/day, respectively. The required architecture for the clinic composes of 40 kW solar PV system, 3 numbers of 10 kW wind turbines, 8.6 kW fuel cell, 25 kW electrolyser and 40 kg hydrogen tank capacity. The capital cost of the microgrid was found to be $177,600 with a net present cost of $206,323. The levelised cost of energy of the system was determined to be 2.34 $/kWh. The project has a breakeven grid extension distance of 8.81 km. Since this distance is less than the nearest grid extension distance of 21.35 km, it is established that the proposed renewable energy microgrid with a hydrogen storage system is a viable option for the rural community health clinic.     

Analysis of the wind energy market in Denmark and future interactions with an emerging hydrogen market

The transition from fossil fuels to renewable energy sources is critical to reduce future emissions and mitigate the consequences hereof. Yet, the expansion of renewable energy, especially the highly fluctuating production of wind energy, poses economic challenges to the existing energy system in Denmark. This paper investigates the economic feasibility of integrating a 250 kW, 500 kW, 750 kW and 1 MW water electrolysis system in the existing Danish energy market to exploit excessive off- and onshore wind energy for hydrogen production used as fuel for transportation purposes. In 2018, Danish wind turbines produced excess energy during 1238 h, which poses a capacity constraint as the electrolysis systems are limited to only produce hydrogen for 14% of the total available annual hours. This paper concludes that the net present value of each investment is negative as the fixed and variable production costs exceeds the generated revenues and it is therefore not economical feasible to invest in an electrolysis system with the purpose of only operating whenever excess off- and onshore wind energy is available.     

A wind–PV-battery hybrid power system at Sitakunda in Bangladesh

The measured wind data of Local Government Engineering Department (LGED) for 2006 at 30 m height shows a good prospect for wind energy extraction at the site. For a few months and hours the speed is below the cut in speeds of the available turbines in the market. The predicted solar radiation data from directly related measured cloud cover and sunshine duration data of Bangladesh Meteorological Department (BMD) for 1992–2003 indicates that a reliable power system can be developed over the year if the solar energy technology is merged with the wind energy technologies for this site. This research work has studied on optimization of a wind–photovoltaic-battery hybrid system and its performance for a typical community load. The assessment shows that least cost of energy (COE) is about USD 0.363/kWh for a community using 169 kWh/day with 61 kW peak and having minimum amount of access or unused energy. Moreover, compared to the existing fossil fuel-based electricity supply, such an environment friendly system can mitigate about 25 t CO₂/yr. The analysis also indicates that wind–PV-battery is economically viable as a replacement for conventional grid energy supply for a community at a minimum distance of about 17 km from grid.     

Dynamic behavior of a stand-alone hybrid power generation system of wind turbine,microturbine, solar array and battery storage

This paper presents dynamic behavior and simulation results in a stand-alone hybrid power generation system of wind turbine, microturbine, solar array and battery storage. The hybrid system consists of a 195 kW wind turbine, an 85 kW solar array; a 230 kW microturbine and a 2.14 kAh lead acid battery pack optimized based on economic analysis using genetic algorithm (GA). At first, a developed Lyapunov model reference adaptive feedback linearization method accompanied by an indirect space vector control is applied for extraction of maximum energy from a variable speed wind power generation system. Then, a fuzzy logic controller is designed for the mentioned purpose and its performance is compared with the proposed adaptive controller. For meeting more load demands, the solar array is integrated with the wind turbine. In addition, the microturbine and the battery storage are combined with the wind and solar power generation system as a backup to satisfy the load demand under all conditions.A supervisory controller is designed in order to manage energy between the maximum energy captured from the wind turbine/solar arrays, and consumed energies of the load, dump load, battery state of charge (SOC), and generated energy by the microturbine. Dynamic modeling and simulation are accomplished using MATLAB Simulink? 7.2.     

Impact of hydrogen energy storage on California electric power system: Towards 100% renewable electricity

Decarbonization of the power sector is a key step towards greenhouse gas emissions reduction. Due to the intermittent nature of major renewable sources like wind and solar, storage technologies will be critical in the future power grid to accommodate fluctuating generation. The storage systems will need to decouple supply and demand by shifting electrical energy on many different time scales (hourly, daily, and seasonally). Power-to-Gas can contribute on all of these time scales by producing hydrogen via electrolysis during times of excess electrical generation, and generating power with high-efficiency systems like fuel cells when wind and solar are not sufficiently available. Despite lower immediate round-trip efficiency compared to most battery storage systems, the combination of devices used in Power-to-Gas allows independent scaling of power and energy capacities to enable massive and long duration storage. This study develops and applies a model to simulate the power system balance at very high penetration of renewables. Novelty of the study is the assessment of hydrogen as the primary storage means for balancing energy supply and demand on a large scale: the California power system is analyzed to estimate the needs for electrolyzer and fuel cell systems in 100% renewable scenarios driven by large additions of wind and solar capacities. Results show that the transition requires a massive increase in both generation and storage installations, e.g., a combination of 94 GW of solar PV, 40 GW of wind, and 77 GW of electrolysis systems. A mix of generation technologies appears to reduce the total required capacities with respect to wind-dominated or solar-dominated cases. Hydrogen storage capacity needs are also evaluated and possible alternatives are discussed, including a comparison with battery storage systems.     

Design and thermodynamic modeling of a renewable energy based plant for hydrogen production and compression

In the examined paper, a solar and wind energy supported integrated cycle is designed to produce clean power and hydrogen with the basis of a sustainable and environmentally benign. The modeled study mainly comprises of four subsystems; a solar collector cycle which operates with Therminol VP1 working fluid, an organic Rankine cycle which runs with R744 fluid, a wind turbine as well as hydrogen generation and compression unit. The main target of this work is to investigate a thermodynamic evaluation of the integrated system based on the 1st and 2 nd laws of thermodynamics. Energetic and exergetic efficiencies, hydrogen and electricity generation rates, and irreversibility for the planned cycle and subsystems are investigated according to different parameters, for example, solar radiation flux, reference temperature, and wind speed. The obtained results demonstration that the whole energy and exergy performances of the modeled plant are 0.21 and 0.16. Additionally, the hydrogen generation rate is found as 0.001457 kg/s, and the highest irreversibility rate is shown in the heat exchanger subcomponents. Also, the net power production rate found to be 195.9 kW and 326.5 kW, respectively, with organic Rankine cycle and wind turbine. The final consequences obtained from this work show that the examined plant is an environmentally friendly option, which in terms of the system's performance and viable, for electrical power and hydrogen production using renewable energy sources.     

Analytical model for predicting the performance of photovoltaic array coupled with a wind turbine in a stand-alone renewable energy system based on hydrogen

We present the results of an analysis of the performance of a photovoltaic array that complement the power output of a wind turbine generator in a stand-alone renewable energy system based on hydrogen production for long-term energy storage. The procedure for estimating hourly solar radiation, for a clear sunny day, from the daily average solar insolation is also given. The photovoltaic array power output and its effective contribution to the load as well as to the energy storage have been determined by using the solar radiation usability concept. The excess and deficit of electrical energy produced from the renewable energy sources, with respect to the load, govern the effective energy management of the system and dictate the operation of an electrolyser and a fuel cell generator. This performance analysis is necessary to determine the effective contribution from the photovoltaic array and the wind turbine generator and their contribution to the load as well as for energy storage.     

Techno-economic analysis of a wind–solar hybrid renewable energy system with rainwater collection feature for urban high-rise application

The technical and economic feasibility study of an innovative wind–solar hybrid renewable energy generation system with rainwater collection feature for electrical energy generation is presented in this paper. The power generated would supply part of the energy requirements of the high-rise building where the system is installed. The system integrates and optimizes several green technologies; including urban wind turbine, solar cell module and rain water collector. The design was conceptualized based on the experiences acquired during the development and testing of a suitable wind turbine for Malaysian applications. It is compact and can be built on top of high-rise buildings in order to provide on-site renewable power to the building. It overcomes the inferior aspect on the low wind speed by channeling and increasing the speed of the high altitude free-stream wind through the power-augmentation-guide-vane (PAGV) before it enters the wind turbine at the center portion. The shape or appearance of the PAGV that surrounds the wind turbine can be blended into the building architecture without negative visual impact (becomes part of the building). The design improves the starting behavior of wind turbines. It is also safer to people around and reduces noise pollution. The techno-economic analysis is carried out by applying the life cycle cost (LCC) method. The LCC method takes into consideration the complete range of costs and makes cash flows time-equivalent. The evaluations show that for a system with the PAGV (30 m diameter and 14 m high) and an H-rotor vertical axis wind turbine (17 m diameter and 9 m high) mounted on the top of a 220 m high building, the estimated annual energy savings is 195.2 MW h/year.     

Effect of wind energy system performance on optimal renewable energy model-an analysis

The Optimal Renewable Energy Model (OREM) has been developed to determine the optimum level of renewable energy sources utilisation in India for the year 2020–21. The model aims at minimising costefficiency ratio and determines the optimum allocation of different renewable energy sources for various end-uses. The extent of social acceptance level, potential limit, demand and reliability will decide the renewable energy distribution pattern and are hence used as constraints in the model. In this paper, the performance and reliability of wind energy system and its effects on OREM model has been analysed. The demonstration windfarm (4 MW) which is situated in Muppandal, a village in the southern part of India, has been selected for the study. The windfarm has 20 wind turbine machines of 200 KW capacity. The average technical availability, real availability and capacity factor have been analysed from 1991 to 1995 and they are found to be 94.1%, 76.4% and 25.5% respectively. The reliability factor of wind energy system is found to be 0.5 at 10,000 hours. The OREM model is analysed considering the above said factors for wind energy system, solar energy system and biomass energy systems. The model selects wind energy for pumping end-use to an extent of 0.3153×10¹⁵ KJ.     

Sustainable energy planning based on a stand-alone hybrid renewableenergy/hydrogen power system: Application in Karpathos island, Greece

This study presents the sustainable planning of a renewables-based energy system, which aims to fulfil the electric needs of the island by replacing the existing diesel generators with new wind farms, photovoltaic installations and hydrogen production systems. Electric system design and least cost planning analysis were concluded using historic data from both demand and supply sides. An optimal “sustainable island” scheme should ensure 100% use of renewable energy resources for power generation, while hydrogen production is ideal for covering storage and transportation needs. Due to its morphology and scale, Karpathos applies perfectly for wind and solar energy systems, due to increased solar resource (about 1790 kWh/m².year of global irradiation) and high wind potential (average of 9 m/s in specific locations). Therefore, this case study examines an increase in RES penetration up to 20% in the electric energy mixture, a hydrogen production plan just for the needs of transport and a more aggressive, 100% renewables scheme that ensures a self-fulfilling energy system based on indigenous renewable resources.     

Development of FPGA based power flow monitoring system in a microgrid

In recent decades, smart grid has become increasingly attractive to both energy producers and consumers. Amongst the main challenges for the successful realization of smart grid includes the integration of renewable energy resources, real time demand response and management of intermittent energy resources. Apart from smart grid, the development of micro-grids should take into consideration of issues such as the system performance, modelling, monitoring and controlling of the micro-grids. In particular, the recent advancements in information and communication technologies (ICTs) could facilitate the effective development of the future micro-grid system. The goal of the study is design of a system, based on FPGA, which monitors the power flow of the Microgrids. First of all a MG system installed in the laboratory of Firat University Electrical and Electronics Engineering Department consists of 1.2 kWp grid connected PV system, 5 kW micro hydro turbine, 0.5 kW wind turbine and 0.1 kW fuel cell unit was introduced. Afterwards, for smart-grids, a system of power flow that has a powerful high sampling rate was dwelt upon. During implementations, the data collected from the power system was transmitted to the FPGA cards located in open area by wireless data-monitoring card. This study has contributed to studies of other researchers by means of the monitoring system which has a high sampling frequency.     

Design and set up of a hybrid power system (PV-WT-URFC) for a stand-alone application in Mexico

The Mexican territory has a large potential for renewable energy development, such as geothermal, hydro, biofuels, wind and solar. Thus, a 2.5 kW hybrid power system (solar, wind and hydrogen) was designed and installed to meet the power demand for a stand-alone application at the University of Zacatecas. The hybrid unit integrates three power energy sources –a photovoltaic system (PV), a micro-wind turbine (WT), a prototype of a unitized regenerative fuel cell (URFC) and energy storage devices (batteries)– in addition to their interaction methodology. The main contribution of this work is the URFC integration to a hybrid power system for the production of H₂ (water electrolyzer mode) and energy (fuel cell mode). These three energy technologies were connected in parallel, synchronized to the energy storage system and finally coupled to a power conversion module. To achieve the best performance and energy management, an energy management and control strategy was developed to the properly operation of the power plant. A meteorological station that has wireless sensors for the temperature, the humidity, the solar radiation and the wind speed provides the necessary information (in real time) to the monitor and control software, which computes and executes the short and mid–term decisions about the energy management and the data storage for future analysis.