Techno-economic feasibility of photovoltaic,wind, diesel and hybrid electrification systems for off-grid rural electrification in Colombia

Electrification to rural and remote areas with limited or no access to grid connection is one of the most challenging issues in developing countries like Colombia. Due to the recent concerns about the global climatic change and diminishing fuel prices, searching for reliable, environmental friendly and renewable energy sources to satisfy the rising electrical energy demand has become vital. This study aims at analyzing the application of photovoltaic (PV) panels, wind turbines and diesel generators in a stand-alone hybrid power generation system for rural electrification in three off-grid villages in Colombia with different climatic characteristics. The areas have been selected according to the “Colombia’s development plan 2011–2030 for non-conventional sources of energy”. First, different combinations of wind turbine, PV, and diesel generator are modeled and optimized to determine the most energy-efficient and cost-effective configuration for each location. HOMER software has been used to perform a techno-economic feasibility of the proposed hybrid systems, taking into account net present cost, initial capital cost, and cost of energy as economic indicators.     

Analysis and techno-economic assessment of renewable hydrogen production and blending into natural gas for better sustainability

In this study, comprehensive thermodynamic analysis and techno-economic assessment studies of the renewable hydrogen production and its blending with natural gas in the existing pipelines are performed. Solar and wind energy-based on-grid and off-grid power systems are designed and compared in energy, exergy, and cost. Solar PV panels and wind turbines are particularly considered for electricity and hydrogen production for residential applications in an environmentally benign way. Fuel cell units are included to supply continuous electricity in the off-grid system. Here, the heat required for a community consisting of 100 houses is provided by hydrogen and natural gas mixture as a more environmentally benign fuel. The costs of capital, fuel, operation, and maintenance are calculated and evaluated in detail. The total net present costs are calculated as $6.95 million and $2.47 million for the off-grid and on-grid power systems, respectively. For the off-grid system, energy and exergy efficiencies are calculated as 32.64% and 40.73%, respectively. Finally, the energy and exergy efficiencies of the on-grid system are determined as 26.58% and 35.25%, respectively.     

Technico-economic analysis of off grid solar PV/Fuel cell energy system for residential community in desert region

A technico-economic analysis based on integrated modeling, simulation, and optimization approach is used in this study to design an off grid hybrid solar PV/Fuel Cell power system. The main objective is to optimize the design and develop dispatch control strategies of the standalone hybrid renewable power system to meet the desired electric load of a residential community located in a desert region. The effects of temperature and dust accumulation on the solar PV panels on the design and performance of the hybrid power system in a desert region is investigated. The goal of the proposed off-grid hybrid renewable energy system is to increase the penetration of renewable energy in the energy mix, reduce the greenhouse gas emissions from fossil fuel combustion, and lower the cost of energy from the power systems. Simulation, modeling, optimization and dispatch control strategies were used in this study to determine the performance and the cost of the proposed hybrid renewable power system. The simulation results show that the distributed power generation using solar PV and Fuel Cell energy systems integrated with an electrolyzer for hydrogen production and using cycle charging dispatch control strategy (the fuel cell will operate to meet the AC primary load and the surplus of electrical power is used to run the electrolyzer) offers the best performance. The hybrid power system was designed to meet the energy demand of 4500 kWh/day of the residential community (150 houses). The total power production from the distributed hybrid energy system was 52% from the solar PV, and 48% from the fuel cell. From the total electricity generated from the photovoltaic hydrogen fuel cell hybrid system, 80.70% is used to meet all the AC load of the residential community with negligible unmet AC primary load (0.08%), 14.08% is the input DC power for the electrolyzer for hydrogen production, 3.30% are the losses in the DC/AC inverter, and 1.84% is the excess power (dumped energy). The proposed off-grid hybrid renewable power system has 40.2% renewable fraction, is economically viable with a levelized cost of energy of 145 $/MWh and is environmentally friendly (zero carbon dioxide emissions during the electricity generation from the solar PV and Fuel Cell hybrid power system).     

考虑碳自然循环的离网型风/光-火联合供能系统容量优化配置

针对合理规划离网型风/光-火联合供能系统使其达到碳中和要求的问题,首先考虑风光出力不确定性对新能源为主的离网型供能系统可靠性的影响,提出离网型风/光-火联合供能系统的基本结构;其次,基于自然界可消纳CO₂上限与世界能源需求总量之间的关系,建立供能系统的碳自然循环模型;以系统年总费用值最小为目标,建立供能系统容量优化配置数学模型,并采用粒子群算法求解。基于某实际离网型联合供能系统算例分析表明：所述容量优化配置方法在以较低成本保证供能可靠性的同时,可实现离网型风/光-火联合供能系统CO₂的“净零排放”。     

Providing all global energy with wind,water, and solar power,Part I: Technologies,energy resources,quantities and areas of infrastructure,and materials

Climate change, pollution, and energy insecurity are among the greatest problems of our time. Addressing them requires major changes in our energy infrastructure. Here, we analyze the feasibility of providing worldwide energy for all purposes (electric power, transportation, heating/cooling, etc.) from wind, water, and sunlight (WWS). In Part I, we discuss WWS energy system characteristics, current and future energy demand, availability of WWS resources, numbers of WWS devices, and area and material requirements. In Part II, we address variability, economics, and policy of WWS energy. We estimate that ∼3,800,000 5 MW wind turbines, ∼49,000 300 MW concentrated solar plants, ∼40,000 300 MW solar PV power plants, ∼1.7 billion 3 kW rooftop PV systems, ∼5350 100 MW geothermal power plants, ∼270 new 1300 MW hydroelectric power plants, ∼720,000 0.75 MW wave devices, and ∼490,000 1 MW tidal turbines can power a 2030 WWS world that uses electricity and electrolytic hydrogen for all purposes. Such a WWS infrastructure reduces world power demand by 30% and requires only ∼0.41% and ∼0.59% more of the world's land for footprint and spacing, respectively. We suggest producing all new energy with WWS by 2030 and replacing the pre-existing energy by 2050. Barriers to the plan are primarily social and political, not technological or economic. The energy cost in a WWS world should be similar to that today.     

A 100% wind,water, sunlight (WWS) all-sector energy plan for Washington State

This study analyzes the potential and consequences of Washington State's use of wind, water, and sunlight (WWS) to produce electricity and electrolytic hydrogen for 100% of its all-purposes energy (electricity, transportation, heating/cooling, industry) by 2050, with 80–85% conversion by 2030. Electrification plus modest efficiency measures can reduce Washington State's 2050 end-use power demand by ∼39.9%, with ∼80% of the reduction due to electrification, and can stabilize energy prices since WWS fuel costs are zero. The remaining demand can be met, in one scenario, with ∼35% onshore wind, ∼13% offshore wind, ∼10.73% utility-scale PV, ∼2.9% residential PV, ∼1.5% commercial/government PV, ∼0.65% geothermal, ∼0.5% wave, ∼0.3% tidal, and ∼35.42% hydropower. Converting will require only 0.08% of the state's land for new footprint and ∼2% for spacing between new wind turbines (spacing that can be used for multiple purposes). It will further result in each person in the state saving ∼$85/yr in direct energy costs and ∼$950/yr in health costs [eliminating ∼830 (190–1950)/yr statewide premature air pollution mortalities] while reducing global climate costs by ∼$4200/person/yr (all in 2013 dollars). Converting will therefore improve health and climate while reducing costs.     

Off-grid solar powered charging station for electric and hydrogen vehicles including fuel cell and hydrogen storage

This paper designs an off-grid charging station for electric and hydrogen vehicles. Both the electric and hydrogen vehicles are charged at the same time. They appear as two electrical and hydrogen load demand on the charging station and the charging station is powered by solar panels. The output power of solar system is separated into two parts. On part of solar power is used to supply the electrical load demand (to charge the electric vehicles) and rest runs water electrolyzer and it will be converted to the hydrogen. The hydrogen is stored and it supplies the hydrogen load demand (to charge the hydrogen-burning vehicles). The uncertainty of parameters (solar energy, consumed power by electrical vehicles, and consumed power by hydrogen vehicles) is included and modeled. The fuel cell is added to the charging station to deal with such uncertainty. The fuel cell runs on hydrogen and produces electrical energy to supply electrical loading under uncertainties. The diesel generator is also added to the charging station as a supplementary generation. The problem is modeled as stochastic optimization programming and minimizes the investment and operational costs of solar and diesel systems. The introduced planning finds optimal rated powers of solar system and diesel generator, operation pattern for diesel generator and fuel cell, and the stored hydrogen. The results confirm that the cost of changing station is covered by investment cost of solar system (95%), operational cost of diesel generator (4.5%), and investment cost of diesel generator (0.5%). The fuel cell and diesel generator supply the load demand when the solar energy is zero. About 97% of solar energy will be converted to hydrogen and stored. The optimal operation of diesel generator reduces the cost approximately 15%.     

Economic-environmental energy supply of mobile base stations in isolated nanogrids with smart plug-in electric vehicles and hydrogen energy storage system

The mobile base stations (MBS) are fundamental communication devices that ensure the constant stream of interconnectivity. However, they are mostly installed in off-grid regions. This study investigates the economic-environmental energy supply of a MBS in an isolated nanogrid (ING) that also includes a hydrogen energy storage system (HES), photovoltaic (PV) system, controllable plug-in electric vehicles (PEV) and a diesel generator (DG). A novel mixed-integer second-order cone programming (MISOCP) formulation is proposed to capture the nonlinearities of the various components through a convex optimization model. The study included different uncertainties including the traffic rate of the MBS, driving schedule of the PEVs, and PV generation via a hybrid stochastic programming (SP) and robust optimization (RO) methods. The influence of the coordinated PEV charging strategy, risk-averse RO and multi-objective optimization was studied through various case studies. The outcomes show that coordinated PEV-charging can have a significant contribution in reducing the risks and curtailing both cost and emission objective functions, while using economic-environmental operation model can cut the emissions by 17.70%.     

State-of-art review of the optimization methods to design the configuration of hybrid renewable energy systems (HRESs)

The current research aims to present an inclusive review of latest research works performed with the aim of improving the efficiency of the hybrid renewable energy systems (HRESs) by employing diverse ranges of the optimization techniques, which aid the designers to achieve the minimum expected total cost, while satisfying the power demand and the reliability. For this purpose, a detailed analysis of the different classification drivers considering the design factors such as the optimization goals, utilized optimization methods, grid type as well as the investigated technology has been conducted. Initial results have indicated that among all optimization goals, load demand parameters including loss of power supply probability (LPSP) and loss of load probability (LLP), cost, sizing (configuration), energy production, and environmental emissions are the most frequent design variables which have been cited the most. Another result of this paper indicates that almost 70% of the research projects have been dedicated towards the optimization of the off-grid applications of the HRESs. Furthermore, it has been demonstrated that, integration of the PV, wind and battery is the most frequent configuration. In the next stage of the paper, a review concerning the sizing methods is also carried out to outline the most common techniques which are used to configure the components of the HRESs. In this regard, an analysis covering the optimized indicators such as the cost drivers, energy index parameters, load indicators, battery’s state of charge, PV generator area, design parameters such as the LPSP, and the wind power generation to load ratio, is also performed.     

Cost analysis of off-grid renewable hybrid power generation system on Ui Island,South Korea

Diesel engine power plants are still widely used on many remote islands in South Korea, despite their disadvantages. Aiming to solve economic and environmental pollution problems, a remote island case study was conducted on Ui Island, aiming to offer a zero-emissions solution by using renewable energy sources in an off-grid application. Power was generated from solar, wind, and hydrogen sources. Li-ion batteries and hydrogen were used as energy storage systems. In addition, PV/battery, wind/battery, PV/wind/battery, PV/battery/PEMFC, wind/battery/PEMFC, and PV/wind/battery/PEMFC systems were simulated using the HOMER software to determine the optimal sizes and techno-economic feasibility. The results show that the PV/wind/battery/PEMFC system is the best system. The configuration of the system consists of 990-kW PV panels, 700-kW wind turbines, a 1088-kWh Li-ion battery bank, 534-kW converter, 300-kW PEMWE system, 300-kg hydrogen tank, and 100-kW PEMFC system. The total NPC of the system is $5,276,069, and the LCOE is 0.366 $/kWh.     

Comparative impacts of wind and photovoltaic generation on energy storage for small islanded electricity systems

This paper addresses the annual energy storage requirements of small islanded electricity systems with wind and photovoltaic (PV) generation, using hourly demand and resource data for a range of locations in New Zealand. Normalised storage capacities with respect to annual demand for six locations with winter-peaking demand profiles were lower for wind generation than for PV generation, with an average PV:wind storage ratio of 1.768:1. For two summer-peaking demand profiles, normalised storage capacities were lower for PV generation, with storage ratios of 0.613:1 and 0.455:1. When the sensitivity of storage was modelled for winter-peaking demand profiles, average storage ratios were reduced. Hybrid wind/PV systems had lower storage capacity requirements than for wind generation alone for two locations. Peak power for storage charging was generally greater with PV generation than with wind generation, and peak charging power increased for the hybrid systems. The results are compared with those for country-scale electricity systems, and measures for minimising storage capacity are discussed. It is proposed that modelling of storage capacity requirements should be included in the design process at the earliest possible stage, and that new policy settings may be required to facilitate a transition to energy storage in fully renewable electricity systems.     

Robust design of off-grid solar-powered charging station for hydrogen and electric vehicles via robust optimization approach

In this article, a robust optimization approach for designing an off-grid solar-powered charging station is proposed to provide electric vehicles (EVs) with electricity and hydrogen vehicles (HV) with hydrogen. A water electrolyzer (WE) is installed in the system to produce and store hydrogen, which is used by the HVs and fuel cell (FC). During the inaccessibility of the photovoltaic (PV) system to feed the EVs, the FC runs on hydrogen to regenerate electricity. Besides, in case the PV system and FC have power shortage to meet the demand of EVs, a diesel generator contributes to electricity production. There are uncertainties involved in the power profile of the PV system as well as the hydrogen and electric demands of the charging station. The novelty of this paper is to integrate robust optimization as a powerful nonstochastic framework into the mixed-integer linear programming (MILP) of the deterministic model to deal with the uncertainties. The technical and economic results prove that the construction of the charging station by considering the highs level of robustness against the negative impacts of uncertainties leads to higher capacities of the PV system and diesel generator. Consequently, the total annualized cost increases from $ 287,256 in deterministic mode to $ 326,757 in robust mode, by 13.75%.     

Constructing an innovative Bio-Hydrogen Integrated Renewable Energy System

Hybrid Renewable Energy Systems (HRES) offer alternative energy options that deliver distributed power generation for isolated loads. However, the production of energy from both wind turbines and solar PV systems is weather-dependent. In this study, we developed an innovative Bio-Hydrogen Integrated Renewable Energy System (BHIRES) based on the integration of hydrogen generation from biomass fermentation, renewable energy power generation, hydrogen generation from water electrolysis, a hydrogen storage device, and a fuel cell providing combined heat and power. BHIRES can provide electric power, thermal energy, and hydrogen, with the additional function of processing biomass waste and wastewater. As indicated by results of the economic analysis conducted in this study, the cost of electricity and the average energy cost of using BHIRES are both lower than those for wind/PV/hydrogen HRES. Therefore, this system is ideal for users in remote areas such as islands, and farms in mountainous areas.     

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.     

Optimal operation of microgrid using hybrid differential evolution and harmony search algorithm

This paper proposes the generation scheduling approach for a microgrid comprised of conventional generators, wind energy generators, solar photovoltaic (PV) systems, battery storage, and electric vehicles. The electrical vehicles (EVs) play two different roles: as load demands during charging, and as storage units to supply energy to remaining load demands in the MG when they are plugged into the microgrid (MG). Wind and solar PV powers are intermittent in nature; hence by including the battery storage and EVs, the MG becomes more stable. Here, the total cost objective is minimized considering the cost of conventional generators, wind generators, solar PV systems and EVs. The proposed optimal scheduling problem is solved using the hybrid differential evolution and harmony search (hybrid DE-HS) algorithm including the wind energy generators and solar PV system along with the battery storage and EVs. Moreover, it requires the least investment.     

Two-stage stochastic-based scheduling of multi-energy microgrids with electric and hydrogen vehicles charging stations,considering transactions through pool market and bilateral contracts

In order to mitigate greenhouse gas emissions and improve energy efficiency, sustainable energy systems such as multi-energy microgrids (MEMGs) with the high penetration of renewable energy resources (RES) and satisfying different energy needs of consumers have received significant attention in recent years. MEMGs, by relying on renewable resources and energy storage systems along with energy conversion systems, play an essential role in sustainability of energy supply. However, renewable energies are uncertain due to the intermittent nature of solar and wind energy sources. Thus, optimal operation of the MEMGs with the consideration of the uncertainties of RES is necessary to achieve sustainability. In this paper, risk constrained scheduling of a MEMG is carried out with the presence of the PV, wind, biomass, electric vehicles (EVs) and hydrogen vehicles (HVs) charging stations, combined heat and power (CHP), boiler, hydrogen electrolyzer (HE), cryptocurrency miners (CMs), electrical, thermal and hydrogen storage systems, responsive demands. From the trading and business model side, the proposed MEMG optimized operation relies on bilateral contracts between producers and consumers and pool electricity markets. A two-stage stochastic programming method is used for considering the uncertainties of electrical, thermal and hydrogen demands, EV and HV charging stations load, CM load, PV and wind power, and the price of electricity purchased from the pool market. The proposed mixed integer linear programming (MILP) model is solved using the CPLEX solver in GAMS which guarantees to achieve a globally optimal solution. The results show that due to the certain prices of bilateral contracts, the possibility of transaction by bilateral contracts decreases the risk metric CVaR by 50.42%. The simulation results demonstrate that risk of high operation costs while considering flexibility sources, such as storages and demand response (DR) programs, is decreased by 5.45% and 4.6%, respectively. As far as operation costs are concerned, results reveal that using renewable resources decreases operation costs by 34.47%. Moreover, the operation cost is reduced by 5.94% and 4.57% in the presence of storage units and DR programs, respectively. In the same way, storages and DR programs decrease cost of purchased electricity by 13.47% and 14.46%, respectively.     

Renewable decentralized in developing countries: Appraisal from microgrids project in Senegal

Sahelian developing countries depend heavily on oil-import for the supply of their increasing energy demand. This setup leads to an imbalance in the balance of payment, an increase of debt and budget asphyxia, whereas renewable resources are widely and abundantly available. The objective of this paper is to carry out a feasibility analysis of off-grid stand-alone renewable technology generation system for some remote rural areas in one Sahelian country. A survey conducted in 2006, within the framework of microgrids project, in rural areas located in three different regions in Senegal (Thies, Kaolack and Fatick) permits determination of demand estimations. Two reference technologies are chosen, namely a solar photovoltaic (PV) system of 130 Wc for solar endowment and a wind turbine of 150 W for wind speed. Taking into account the life-cycle-cost and the environmental externalities costs, our results show that the levelized electricity costs of PV technology are lower than the cost of energy from the grid extension for all these three regions. Thus, decentralized PV technologies are cost-competitive in comparison to a grid extension for these remote rural areas. For wind technology viabilities results are attained with a requirement demand lower than 7. 47 KWh/year for Thies and 7.884 KWh/year for the two remaining areas, namely Kaolack and Fatick. The additional advantage of the proposed methodology is that it allows the environmental valuation of energy generated from non-renewable resource.     

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.     

Performance assessment of an electrochemical hydrogen production and storage system for solar hydrogen refueling station

This paper investigates the performance of a hydrogen refueling system that consists of a polymer electrolyte membrane electrolyzer integrated with photovoltaic arrays, and an electrochemical compressor to increase the hydrogen pressure. The energetic and exergetic performance of the hydrogen refueling station is analyzed at different working conditions. The exergy cost of hydrogen production is studied in three different case scenarios; that consist of i) off-grid station with the photovoltaic system and a battery bank to supply the required electric power, ii) on-grid station but the required power is supplied by the electric grid only when solar energy is not available and iii) on-grid station without energy storage. The efficiency of the station significantly increases when the electric grid empowers the system. The maximum energy and exergy efficiencies of the photovoltaic system at solar irradiation of 850 W m-2 are 13.57% and 14.51%, respectively. The exergy cost of hydrogen production in the on-grid station with energy storage is almost 30% higher than the off-grid station. Moreover, the exergy cost of hydrogen in the on-grid station without energy storage is almost 4 times higher than the off-grid station and the energy and exergy efficiencies are considerably higher.     

Transforming the electricity generation of the Berlin–Brandenburg region,Germany

We present possible steps for Germany's capital region for a pathway towards high-level renewable energy contributions. To this end, we give an overview of the current energy policy and status of electricity generation and demand of two federal states: the capital city Berlin and the surrounding state of Brandenburg. In a second step we present alternative, feasible scenarios with focus on the years 2020 and 2030. All scenarios were numerically evaluated in hourly time steps using a cost optimisation approach. The required installed capacities in an 80% renewables scenario in the year 2020 consist of 8.8 GW wind energy, 4.8 GW photovoltaics, 0.4 GW_el bioenergy, 0.6 GW_el methanation and a gas storage capacity of 180 GWh_th. In order to meet a renewable electricity share of 100% in 2030, approximately 9.5 GW wind energy, 10.2 GW photovoltaics and 0.4 GW_el bioenergy will be needed, complemented by a methanation capacity of about 1.5 GW_el and gas storage of about 530 GWh_th. In 2030, an additional 11 GWh_el of battery storage capacity will be required. Approximately 3 GW of thermal gas power plants will be necessary to cover the residual load in both scenarios. Furthermore, we studied the transmission capacities of extra-high voltage transmission lines in a second simulation and found them to be sufficient for the energy distribution within the investigated region.