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.     

Assessing the potential for a wind power incentive for remote villages in Canada

This paper discusses the uptake potential for a wind–diesel production incentive designed specifically for Canadian northern and remote communities. In spite of having over 300 remote communities with extremely high electricity costs, Canada has had little success in developing remote wind energy projects. Most of Canada’s large-scale wind power has been developed as a direct result of a Federal production incentive implemented in 2002. Using this incentive structure as a successful model, this paper explores how an incentive tailored to remote wind power could be deployed. Micro-power simulations were done to demonstrate that the production incentive designed by the Canadian Wind Energy Association would cost on average $4.7 $Cdn million and could be expected to result in 14.5 MW of wind energy projects in remote villages in Canada over a 10 year period, saving 11.5 $Cdn million dollars in diesel costs annually, displacing 7600 tonnes of CO_2eq emissions and 9.6 million litres of diesel fuel every year.     

Power quality improvement of a stand-alone power system subjected to various disturbances

In wind-diesel stand-alone power systems, the disturbances like random nature of wind power, turbulent wind, sudden changes in load demand and the wind park disconnection effect continuously the system voltage and frequency. The satisfactory operation of such a system is not an easy task and the control design has to take in to account all these subtleties. For maintaining the power quality, generally, a short-term energy storage device is used. In this paper, the performance of a wind-diesel system associated with a superconducting magnetic energy storage (SMES) system is studied. The effect of installing SMES at wind park bus/load bus, on the system performance is investigated. To control the exchange of real and reactive powers between the SMES unit and the wind-diesel system, a control strategy based on fuzzy logic is proposed. The dynamic models of the hybrid power system for most common scenarios are developed and the results presented.     

Potential and economic viability of standalone hybrid systems for a rural community of Sokoto,North-west Nigeria

An assessment of the potential and economic viability of standalone hybrid systems for an off-grid rural community of Sokoto, North-west Nigeria was conducted. A specific electric load profile was developed to suite the community consisting 200 homes, a school and a community health center. The data obtained from the Nigeria Meteorological Department, Oshodi, Lagos (daily mean wind speeds, and daily global solar radiation for 24 years from 1987 to 2010) were used. An assessment of the design that will optimally meet the daily load demand with a loss of load probability (LOLP) of 0.01 was performed, considering 3 stand-alone applications of photovoltaic (PV), wind and diesel, and 3 hybrid designs of wind-PV, wind-diesel, and solar-diesel. The diesel standalone system (DSS) was taken as the basis of comparison as the experimental location has no connection to a distribution network. The HOMER® software optimizing tool was engaged following the feasibility analysis with the RETScreen software. The wind standalone system (WSS) was found to be the optimal means of producing renewable electricity in terms of life cycle cost as well as levelised cost of producing energy at $0.15/(kW$h). This is competitive with grid electricity, which is presently at a cost of approximately $0.09/(kW$h) and 410% better than the conventional DSS at a levelized cost of energy (LCOE) of $0.62/kWh. The WSS is proposed for communities around the study site.     

Optimization of diesel engine performances for a hybrid wind–diesel system with compressed air energy storage

Electricity supply in remote areas around the world is mostly guaranteed by diesel generators. This relatively inefficient and expensive method is responsible for 1.2 million tons of greenhouse gas (GHG) emission in Canada annually. Some low- and high-penetration wind-diesel hybrid systems (WDS) have been experimented in order to reduce the diesel consumption. We explore the re-engineering of current diesel power plants with the introduction of high-penetration wind systems together with compressed air energy storage (CAES). This is a viable alternative to major the overall percentage of renewable energy and reduce the cost of electricity. In this paper, we present the operative principle of this hybrid system, its economic benefits and advantages and we finally propose a numerical model of each of its components. Moreover, we are demonstrating the energy efficiency of the system, particularly in terms of the increase of the engine performance and the reduction of its fuel consumption illustrated and supported by a village in northern Quebec.     

Sizing a hybrid wind-diesel stand-alone system on the basis of minimum long-term electricity production cost

Hybrid wind-diesel systems are an interesting solution for the electrification of isolated consumers. The proposed system, including a properly sized battery, leads to a significant reduction of the fuel consumption, in comparison with a diesel-only installation, also protecting the diesel generator from excessive wear. On the other hand, a properly designed wind-diesel installation remarkably reduces the required battery capacity, in relation to a wind-only based stand-alone system, especially in medium-low wind potential areas. In this context, a complete sizing model, based on a long-term energy production cost analysis is developed, able to predict the optimum configuration of a hybrid wind-diesel stand-alone system on the basis of minimum long-term cost. According to the application results obtained for representative wind potential cases, the proposed hybrid system guarantees one year’s long energy autonomy of a typical remote consumer, presenting a significant cost advantage in relation either to a diesel-only or to a wind-based stand-alone system.     

Canadian remote community power generation: How reformer and fuel cell systems compare with diesel generators

More than three quarters of Canadian remote communities rely solely on diesel generators for electricity generation. The diesel dependency of remote communities has inflated local per capita greenhouse gas emissions and resulted in rising and inconsistent electricity prices that have made community viability reliant on government subsidies. As the diesel generators approach the end of their lifespan replacement, technologies must be considered that will help transition Canadian remote communities from diesel to renewables. Replacing diesel generators with steam reformer and solid oxide fuel cell systems would allow for more efficient diesel generation and would benefit the future implementation of renewable power. A model was generated in Honeywell's UniSim Design Suite to simulate the performance of a diesel fed steam reformer and solid oxide fuel cell system. System operating parameters in the model were optimized to minimize the expected payback period. The system model outputs were compared with expected diesel generator performance for a test case remote community. The test community demonstrated that replacing diesel generators with the proposed steam reformer and solid oxide fuel cell system would result in annual net efficiency improvements of 32%. The efficiency improvement could potentially translate to reductions in carbon dioxide equivalents of over 258 kt and 20‐year savings of over $450 million if all diesel‐reliant Canadian remote communities switched to steam reformer and solid oxide fuel cell systems. In addition to immediate environmental and economic savings, the improved low load performance of the reformer and fuel cell system would allow for the future integration of renewable energy to create highly efficient diesel‐renewable hybrid power plants.     

A feasibility study of hybrid wind power systems for remote communities

Global warming, climate change and the recent global financial crisis have emphasised the need for reducing carbon emissions whilst also ensuring economic feasibility. This study addresses this topic by investigating the technical and economic feasibility of replacing diesel power generation with hybrid wind power systems in remote communities. For this purpose, the economic, technical and environmental characteristics of eight different hybrid wind power systems were established and compared in respect to their performance in the isolated community of French Island (Victoria, Australia). The results obtained in this study demonstrated the economic and environmental superiority of the hybrid wind–diesel–battery system over all other systems studied in this project. This system was found to have the lowest net present cost and cost per kWh among the modelled systems. Furthermore, the results clearly indicated that hybrid wind power systems are, in general, a feasible and preferable alternative to diesel power generation on the French Island. The research methodology and procedure that were developed in this project can be used to investigate and identify the most viable hybrid power system for other remote communities based on their specific environmental, social and economic circumstances.     

Techno-econo-environmental optimal operation of grid-wind-solar electricity generation with hydrogen storage system for domestic scale,case study in Chad

The rapidly growing of population in the developing countries and their lack of access to electricity, especially in the remote or rural areas, is causing huge challenges for on energy production. Energy is an enabler and a reliable energy supply is critical to sustainable socio-economic development for any nation. Most of Chad's people live in villages with no particular power supply system. Exploiting renewable energies is the only means of fostering development and improving people's welfare. This paper attempts at proposing an energy profile and storage model for Chad in vast remote towns. The paper addresses the key energy gap that is hindering on the development of such systems, it models and assess the potential on electricity generation and using hydrogen as surplus power storage system. A techno-econo-environmental survey on a solar-wind hybrid system in 25 towns in Chad is undertaken using NASA data and HOMER Software. Several hybrid scenarios of energy production and storage is analyzed. The results showed that in the electricity generation scenario, the average total NPC for the studied stations was $ 48164 and the average LCOE was $0.573. The lowest LCOE was related to Aouzou station with 0.507 $/kWh and the highest LCOE was obtained for Bol station with 0.604 $/kWh. In the simultaneous electricity and hydrogen generation scenario, the cheapest hydrogen ($4.695/kg) was produced in the “Grid” scenario, which was the same for all of the stations, with a total NPC of $2413770. The most expensive hydrogen ($4.707/kg) was generated in the “Grid-Wind” scenario and Bol stations with a total NPC of $2420186. The paper develops cost effective models for all hybrid systems combination for both electricity and hydrogen generation across Chad. These findings could help policy makers, investors and other developmental agencies make informed choices on energy access for sustainable development for rural communities in Sub Saharan Africa.     

Feasibility study of hybrid retrofits to an isolated off-grid diesel power plant

The green sources of energy are being encouraged to reduce the environmental pollution and combat the global warming of the planet. A target of 12% usage of wind energy only has been agreed by the UNO country members to achieve by 2020. So, the power of the wind is being used to generate electricity both as grid connected and isolated wind-diesel hybrid power plants. This paper performed a pre-feasibility of wind penetration into an existing diesel plant of a village in north eastern part of Saudi Arabia. For simulation purpose, wind speed data from a near by airport and the load data from the village have been used. The hybrid system design tool HOMER has been used to perform the feasibility study. In the present scenario, for wind speed less than 6.0 m/s the, the existing diesel power plant is the only feasible solution over the range of fuel prices used in the simulation. The wind diesel hybrid system becomes feasible at a wind speed of 6.0 m/s or more and a fuel price of 0.1 $/L or more. If the carbon tax is taken into consideration and subsidy is abolished then it is expected that the hybrid system become feasible. The maximum annual capacity shortage did not have any effect on the cost of energy which may be accounted for larger sizes of wind machines and diesel generators. It is recommended that the wind data must be collected at the village at three different heights using a wind mast of 40 m for a minimum of one complete year and then the hybrid system must be re-designed.     

Evaluating and comparing three community small-scale wind electrification projects

Electrification systems based on renewable energy have proven suitable for providing electricity autonomously to rural communities. Among the technical options available, wind systems are increasingly getting attention. In the northern mountains of Peru, at 3800 m.a.s.l., three community wind electrification projects have been implemented. The technical solutions used in each project are different: wind vs. hybrid photovoltaic-wind systems; individual equipment vs. microgrids. This study aims to describe, evaluate and compare these three small-scale community wind electrification projects. The evaluation of the three projects was carried out by comparing previous and present scenario; attention has been focused on project design and technical aspects, socio-economic impacts and sustainability and management model. These three examples shed light on both the advantages and disadvantages of different technological options as well as on appropriate community-level management models.     

State and local economic impacts from wind energy projects: Texas case study

This paper uses the Jobs and Economic Development Impacts (JEDI) model to estimate economic impacts from 1398 MW of wind power development in four counties in west Texas. Project-specific impacts are estimated at the local level (i.e., within a 100-mile radius around the wind farms) and at the state level. The primary economic policy question addressed is how investment in wind energy affects the state and local communities where the wind farms are built. During the four-year construction phase approximately 4100 FTE (full time equivalents) jobs were supported with turbine and supply chain impacts accounting for 58% of all jobs generated. Total lifetime economic activity to the state from the projects equated to more than $1.8 billion, or $1.3 million per MW of installed capacity. The total economic activity to the local communities was also substantial, equating to nearly $730 million over the assumed 20-year life cycle of the farms, or $0.52 million per MW of installed capacity. Given the current level of impacts observed, and the potential for increased impacts via greater utilization of instate manufacturing capacity and the development of trained wind industry specific laborers, Texas appears to be well positioned to see increasing impacts from continued wind development.     

Design requirements for medium-sized wind turbines for remote and hybrid power systems

This paper provides an overview of the design requirements for medium-sized wind turbines intended for use in a remote hybrid power system. The recommendations are based on first-hand experience acquired at the University of Massachusetts through the installation, operation, and upgrade of a 250-kW turbine on a mountain top with difficult access in Western Massachusetts. Experience with the operation of this turbine and the design of its control system, together with a long history in the design and analysis of hybrid power systems, has made it possible to extend the work in Western Massachusetts to remote or hybrid power systems in general. The University test site has many attributes of more remote sites and the overall wind turbine installation is typical of one that could power a hybrid wind system. For example, access to the site is limited due to steep terrain, snow, and environmental restrictions. Also, the power lines feeding the turbine exhibit voltage sags and phase imbalance, especially during start-up. This paper is based on the experience gained from the operation of this wind turbine and assesses the requirements for the design and operation of medium to large wind turbines in remote locations. The work summarizes lessons learned relative to: (1) sensors, communication, and control capabilities; (2) grid connection issues; and (3) weather-related problems. The final section of the paper focuses on design requirements to ensure successful installation and the completion of maintenance and repairs at remote sites.     

Wind-diesel hybrid power system integration in the south Algeria

In most isolated sites situated in south Algeria, the diesel generators are the major source of electrical energy. Indeed, the power supply of these remote regions still poses order problems (technical, economical and ecological). The electricity produced with the help of diesel generators is very expensive and responsible for CO₂ emission. These isolated sites have significant wind energy potential. Hence, the use of twinning wind-diesel is widely recommended, especially to reduce operating deficits. The objective of this paper is to study the global modeling of a hybrid system which compounds wind turbine generator, diesel generator and storage system. This model is based on the control strategy to optimize the functioning of the hybrid system and to consolidate the gains to provide proper management of energy sources (wind, diesel, battery) depending on the load curve of the proposed site. The management is controlled by a controller which ensures the opening/closing of different power switches according to meteorological conditions (wind speed, air mass, temperature, etc).     

Optimised model for community-based hybrid energy system

Hybrid energy system is an excellent solution for electrification of remote rural areas where the grid extension is difficult and not economical. Such system incorporates a combination of one or several renewable energy sources such as solar photovoltaic, wind energy, micro-hydro and may be conventional generators for backup. This paper discusses different system components of hybrid energy system and develops a general model to find an optimal combination of energy components for a typical rural community minimizing the life cycle cost.The developed model will help in sizing hybrid energy system hardware and in selecting the operating options. Micro-hydro-wind systems are found to be the optimal combination for the electrification of the rural villages in Western Ghats (Kerala) India, based on the case study. The optimal operation shows a unit cost of Rs. 6.5/kW h with the selected hybrid energy system with 100% renewable energy contribution eliminating the need for conventional diesel generator.     

PV hybrid systems for rural electrification in Thailand

Photovoltaic (PV) hybrid systems can make a positive contribution to the sustainability of rural communities in developing countries that do not have access to electricity grid. Integration of solar photovoltaic system with diesel generator for remote and rural areas would assist in expanding the electricity access in the tropical region. A survey of PV hybrid system in Thailand during the last decade regarding to status of technology, performance in terms of technical and economic aspects, and their prospects has been presented in this paper.     

Stakeholders’ perspectives on barriers to remote wind–diesel power plants in Canada

Canada has been experimenting with wind–diesel hybrid systems for its remote communities for over 25 years with limited success. This paper discusses the results of a year-long survey that was distributed to stakeholders in wind–diesel systems in remote Canadian communities. These stakeholders include utilities, wind energy technology manufacturers, project developers, researchers, and governments. The analysis shows that there is a strong agreement that capital and operating costs are the most significant barriers to the implementation of wind–diesel systems and that direct project financial incentives, notably production and capital cost incentives designed to reduce these costs are perceived as the most effective way to encourage development. There is a notable disagreement between utilities and governments on one hand, who are split as to the current technical viability of wind–diesel systems, and manufacturers, developers, and researchers on the other, who overwhelmingly believe that wind–diesel systems are mature enough for remote applications.     

Subsidised Solar Lighting: The Only Option for 1 Billion People

Remote rural communities in developing countries are at a similar economic stage of development as was the developed world more than 100 years ago when electricity was used for more than 50 years for lighting and radio only. Not until people could afford refrigerators did electricity demand grow. Without direct capital subsidies by governments and cross subsidies by utilities the developed world would not be as developed as it currently is and certainly not those communities outside major cities and towns. Many rural areas in the developed world would be in a similar energy plight to those currently in the developing world! There currently is no technology that can meet a subsidy free energy supply anywhere in remote rural communities. The least cost option to meet the basic energy needs for the remote developing world is a properly designed solar system (systems designed up to an availability level not down to a price). To supply the one billion people without access to electricity would cost about US$112 billion (2005 $) in total subsidies using solar. But this will be less than the US$450 billion (2005) subsidy to meet their basic lighting needs using diesel energy.The user pays principle might work for McDonalds but 20 years working in developing countries has clearly demonstrated that there is something dramatically wrong with the current economic paradigms where basic infrastructure is required. It should not be the Private Sector that funds the development of remote rural lighting, they have demonstrated that they can only deliver too little too late, but the Public sector through their existing utilities with government direct subsidies if another generation is not to be lost to development. To demonstrate the need for a paradigm shift, over the past 20 years I have implemented and installed solar projects worth more than US$100million in many developing countries, but none with their utilities or energy departments. All the projects have been with rural development authorities that recognised the immediate need of their constituents and were not at all fussed by the concept of subsidisation. They actually know what it was like on the ground. Something that many energy authorities and utilities I fear have no idea about.     

Modelling of solar/diesel/battery hybrid power systems for far-north Cameroon

Solar/diesel/battery hybrid power systems have been modelled for the electrification of typical rural households and schools in remote areas of the far north province of Cameroon. The hourly solar radiation received by latitude-titled and south-facing modules was computed from hourly global horizontal solar radiation of Garoua using Hay's anisotropic model. Using the solar radiation computed for latitude-tilted and south-facing modules, the average daytime temperatures for Garoua and parameters of selected solar modules, the monthly energy production of the solar modules was computed. It was found that BP solar modules with rated power in the range 50–180 Wp produced energy in the range 78.5–315.2 kWh/yr. The energy produced by the solar modules was used to model solar/diesel/battery hybrid power systems that could meet the energy demand of typical rural households in the range 70–300 kWh/yr. It was also found that a solar/diesel/battery hybrid power system comprising a 1440 Wp solar array and a 5 kW single-phase generator operating at a load factor of 70%, required only 136 generator h/yr to supply 2585 kWh/yr or 7 kWh/day to a typical secondary school. The renewable energy fraction obtained in all the systems evaluated was in the range 83–100%. These results show that there is a possibility to increase the access rate to electricity in the far north province without recourse to grid extension or more thermal plants in the northern grid or more independent diesel plants supplying power to remote areas of the province.     

Dynamics and control of isolated wind-diesel power systems

In this paper a comparative dynamic stability study has been carried out for wind-diesel systems with multiplicity of generation. The mathematical model considered for dynamic stability evaluation is based on small signal analysis. The Lyapunov technique is used to evaluate the optimum setting of gain parameters and comparison is made with the values given in the literature. Additionally the diesel unit equipped with a supplementary proportional integral controller is also considered and its effect on the dynamic stability of the system is investigated. It is shown that the wind-diesel system with multiple wind generation has the minimum first swing of oscillations and also higher damping of subsequent swings for disturbances due to load or due to variations in input wind power. Finally, the dynamic responses of the different power systems considered with optimal gain setting are also presented.