HOMER Energy Research Articles

Stand-Alone Hybrid Wind-Diesel Power Systems for Commercial Loads of Turaif-Saudi Arabia - Techno-Economics of Hot Desert Regions for Sustainable Clean Future

Hybrid wind-diesel technology is disseminated world-wide to minimize depletion of fossil-fuels and carbon emissions. Appreciable amount (10-40%) of energy generated is consumed by commercial/residential buildings of Kingdom of Saudi Arabia (K.S.A.). This investigation aims at techno-economic assessment of hybrid wind-diesel systems (HWDS) to satisfy electrical demand (620,000 kWh per year) of a representative commercial building at Turaif (Northern Province, K.S.A.) by analysis of wind speed data. As per the study, the monthly average wind speed of Turaif lies in the range 3.4 - 4.4 meters per second. The configurations simulated include various mixes of 100 kW wind machines (WTG) and diesel systems. The techno-economic evaluation is carried out by using NREL’s (HOMER Energy’s) HOMER software. The results point out that the wind fraction (with zero % load rejection) is 20% for a hybrid configuration composed of one 100 kW WTG together and 175 kW diesel generator. The energy generation cost (COE) from this system is 0.123 $/kWh. Also, 20% wind fraction, results in reducing carbon emissions by 91 tons/year. The diesel operation time is less with higher penetration of wind. Also, emphasis is on effect of wind fraction on energy produced, COE, operational time of diesel sets, un-met load, excess energy, fuel savings, carbon emissions, cost of HWDS, etc.

Techno-economic analysis of off-grid solar/wind/biogas/biomass/fuel cell/battery system for electrification in a cluster of villages by HOMER software

Electrification of villages is a vital step for improving the techno-economic conditions of rural areas and crucial for the country’s overall development. The villages’ welfare is one of the main aims of the rural electrification programs. Rural electrification is relatively costly compared to electrification of urban areas. Now, the research question is to find the best combinations of HRES from the available resources in a given village location that can meet the electricity demand in a sustainable manner and to see whether this is a cost-effective solution or not. This study is an attempt to structure a model of electricity generation based on multiple combinations of HRES with the application of HOMER energy software at an identified off-grid village location in India. The main objectives of this study are to analyze the best-suited configuration of a hybrid RE system out of various combinations to meet the village load requirement reliably, continuously and sustainably. The study also reduces the total system net present cost and least cost of energy (COE) using multi-objective HOMER Pro software. In this study, a resource assessment and demand calculation have been carried out and the COE per unit has been ascertained for different systems and configurations. A combination of PV–Wind–Biomass–Biogas–FC along with battery has been identified as the cheapest and most dependable solution with a COE of $0.214/kWh.

Performance Assessment and Optimization of a Micro-Hydropower Plant: Case of Kigwena in Burundi

A significant characteristic of the power sector in Burundi is a very low electrification rate (about 10 %), mainly dependent on hydro-power and with frequent power outages in dry seasons. Despite having potential for developing various renewable energy technologies, the Burundian Agency for Rural Electrification promoted usage of micro-hydropower plants. Hence, most of these plants are affected by stream-flow fluctuations, especially during the dry seasons. This study aimed to identify a simple, reliable, viable and cost-effective hybrid power system to compensate the power supply intermittencies of the Kigwena micro-hydropower plant. The optimization of the best hybrid combination was evaluated using the microgrid software, HOMER Energy. The study concluded that the most suitable complementary energy resource was solar-PV and the utility grid for smoothing unexpected intermittencies. Economically, these renewable energies were found to be the most techno-economical viable option to upgrade the capacity of the hydropower with the lowest Levelized Cost of Energy of US$ 0.0334 /kWh. This cost was within the range in comparison to the current electricity tariff in Burundi ranging from US$ 0.023/ kWh to US$ 0.072/kWh. The study would be a replicable model for other areas facing similar challenges.

Hydrogen as an energy vector to optimize the energy exploitation of a self-consumption solar photovoltaic facility in a dwelling house

Solar photovoltaic (PV) plants coupled with storage for domestic self-consumption purposes seem to be a promising technology in the next years, as PV costs have decreased significantly, and national regulations in many countries promote their installation in order to relax the energy requirements of power distribution grids. However, electrochemical storage systems are still unaffordable for many domestic users and, thus, the advantages of self-consumption PV systems are reduced. Thus, in this work the adoption of hydrogen systems as energy vectors between a PV plant and the energy user is proposed. As a preliminary study, in this work the design of a PV and hydrogen-production self-consumption plant for a single dwelling is described. Then, a technical and economic feasibility study conducted by modeling the facility within the Homer Energy Pro energy systems analysis tool is reported. The proposed system will be able to provide back not only electrical energy but also thermal energy through a fuel cell or refined water, covering the fundamental needs of the householders (electricity, heat or cooling and water). Results show that, although the proposed system effectively increases the energy local use of the PV production and reduces significantly the energy injections or demands into/from the power grid, avoiding power grid congestions and increasing the nano-grid resilience, operation and maintenance costs may reduce its economic attractiveness for a single dwelling.

Standalone Hybrid Minigrid for Empowering Every Families in Rural Areas without Dependency to Grid Electricity

A standalone hybrid power generation system has been designed for rural areaswhich comprises PV cell, wind, pedal generator and rice husk electricity generatorto produce electricity for 30 families.They will produce energy by them own and also consume themselves. The problem of load shedding will be resolved by the system and they need not to pay anymore other than the installation cost and very low maintenance cost. The system will be totally environment friendly without pollution. For performance analysis the simulation is done in HOMER energy simulation software.

Small-scale 10 kW wind turbine on-grid connected for power supply of two different consumers

In this paper a power supply system based on a 10-kW wind turbine on-grid connected used for two different consumers is analysed. The proposed wind turbine site is located at coordinates 46°57’41”N 25°56’36” E, in the Ceahlau National Park, on the plateau of Ceahlau Mountain. Nearby there are located the two consumers: the Ceahlau Monastery and the Dochia Chalet. The site wind resource is obtained mainly from NASA Surface meteorology and Solar Energy database. The load demand curves, the annual energy consumption and the peak load are obtained considering the standard load profile for these two particular types of consumers. The on-grid power supply system is analysed using HOMER Energy microgrid modelling software for different tourist’s occupancy. Two different wind turbines (XZ and XL) with rated power of 10 kW are comparatively analysed. Selection of the most suitable wind turbine is realized using the Weighted Product Method (WPM), for which nine attributes are used: annual energy production, capacity factor, renewable fraction, grid purchase, grid sales, initial investment, net present cost, levelized cost of energy, and simple payback. For a given criteria weights, the XL model is found to be the most suitable wind turbine.

Microgrid analysis using HOMER: a case study

The integration of renewable energy sources to create microgrids is drawing growing interest to address current energy-related challenges around the globe. Nevertheless, microgrids must be analyzed using specialized tools that allow to conduct operation, technical and economic studies. In that regard, this paper presents a case study in which the software HOMER Energy Pro was implemented to design and analyze the performance of a microgrid. Such microgrid comprises a photovoltaic system, a wind system and a diesel plant. The parameters of the energy systems are based on information about local weather conditions available in databases. Finally, this analysis is performed under two conditions: stand-alone and grid-tied.

Exploring lifecycle energy and greenhouse gas emissions of a case study with ambitious energy compensation goals in a cooling-dominated climate

Achieving low operational energy (OE) consumption in high heating and cooling situations typically leads to well-insulated buildings. In those cases, embodied energy (EE) can exceed the operational share. Specific literature refers mostly to heating-dominated residential buildings, with a clear focus on European, Asian, and North American countries. Information on embodied impacts of buildings other regions is virtually inexistent. This paper aims at estimating lifecycle energy and greenhouse gases (GHG) emissions of selected design versions of a photovoltaic-powered Living Lab in Campinas, Brazil; and at finding the embodied-to-operational impact ratios as well as the main contributors to those overall impacts. Homer Energy software supported sizing of photovoltaic (PV) arrays for ten energy compensation scenarios to, based on simulated OE, determine the feasibility threshold for onsite generation admitted by the building design. We then modelled lifecycle energy and GHG emissions for the net zero (NZE) and threshold energy positive (E + ) versions of the case study design. The Cumulative Energy Demand (CED) and the CML 2001 v.2.05 methods supported embodied energy and global warming potential (GWP) calculations in SimaPro 7.3. The E + building compensates its OE plus non-renewable energy embodied in building products. Steel frame and partitions were the largest contributors to EEG in building products, whilst the insulated façade panels and PV array performed key energy performance roles at comparatively lower embodied impacts. Shifting from NZE towards E + status discretely increased the embodied-to-operational energy ratio (EE:OE), at similar embodied-to-operational GHG emissions (EG:OG) ratios. Pre-use share of lifecycle CED was slightly surpassed by the operational one, whilst responding for 60% of lifecycle GWP. Material replacement over the reference service life contributed significantly to operational impacts. EOL treatment had negligible effect on lifecycle impacts. EE more than tripled OE and embodied emissions exceeded OG by a factor of seven. EEG prominence confirms the crucial need for a harmonized calculation approach, as experienced for operational stage accountancy over the recent years. We acknowledge the high uncertainties involved in using simulated over measured OE consumption and in using foreign LCI databases. The former limitation can be solved by monitoring operational performance upon projects completion. This study offers practical and detailed reference for LCA practitioners in all countries facing the latter challenge, which will persist until integrated national LCI databases finally become available.

Optimal Design of Independent Mini Hydro-photovoltaic-battery-diesel Hybrid Power System for Erin-ijesha Water Fall, Nigeria

In order to provide a sustainable energy system, especially in rural areas where grid electricity is not economically or geographically feasible, renewable energy sources appear to be one of the most effective solutions. However, the fluctuating nature and the high cost of kWhr units produced make the system unreliable and not easily affordable to the rural dwellers. This paper discussed the feasibility of renewable energy hybrid system and proposed a reliable independent Hybrid Power System (HPS) for rural application in Nigeria. Erin-Ijesha a typical rural village in Osun State, Nigeria was used as a case study. Solar irradiation, the hydro potential of the waterfall and load patterns were collected and analyzed for the study area. The electrical load for the village was estimated through the use of questionnaires. HOMER energy modeling software was used to develop the simulation models. The optimized results showed that mini-hydro-photovoltaic-battery combination with Cost of Energy, COE of $0.218/kWh is better than any other combinations considered in the work. It was revealed that purchasing electricity from the grid is better than any other hybrid combinations in terms of COE at $0.121/kWh. Nevertheless, from the result obtained, the HPS is considered cost-efficient and reliable in such rural areas especially where grid extension is geographically or economically infeasible.

Multi-criteria decision analysis for renewable energy integration: A southern India focus

In recent days, sustainability is considered as an important mechanism due to contemporary increase in demands and worldwide limited resources. This paper presents the possibility of integrating a renewable energy system with an existing grid to meet electrical energy demand of institutional buildings located in Indian state of Tamil Nadu. Currently, the Tamil Nadu state electric-grid power is not surplus and experiencing 40% short fall in generation. In this present paper a modern approach for the optimum planning of electric power system (EPS) is proposed based on the Analytic Hierarchy Process (AHP). An intertwined analysis on energy management and techno-economic optimization of grid connected renewable energy system is proposed. The prospects of different fixed tilt solar panels and peak load shifting based energy management are performed through HOMER Energy® simulation. The AHP multi-criteria decision analysis reveals that annual optimum tilt grid connected photovoltaic system is the optimum configuration for study location. The effectiveness of the AHP approach is evaluated with best-worst method and stochastic multi-criteria acceptability analysis for prioritizing the renewable energy system options in order to select best EPS. In addition, the optimum configuration is implemented in the institutional buildings and performance is analyzed under varying climatic conditions.

HYBRID GRIDS ANALYSIS WITH RENEWABLE ENERGY AND THERMAL ENERGY FOR STREET LIGHT -A CASE STUDY

This paper presents a techno-economic assessment for a unique Isolated Hybrid Power System (IHPS) design which could be used for remote areas isolated from the grid which also has the capability of being operated as a smart the hybrid energy system considering solar and wind energy sources for the purpose of street lighting. Solar-Wind Street light is an intelligent, small scale, and off grid LED lighting system. The modelling design and simulations were based on Simulations conducted using the Data collected and HOMER Energy Planning and Design software tools. Its components are solar panel, wind generator system (PVC blowers), Dynamo, LDRs, battery, LED light, charge controller. The energy stored in battery during day time due to solar panel, get extracted by LEDs during the night time (because LDRs get activated due to absence of sun light). Wind also charges the batteries due to wind which is used for glowing street light. The advantage of this idea is to avoid daily running cost and make the system purely off-grid. In this prototype, we have used 12V DC system to supply energy to the lights.

Design and Simulation of an Optimal Mini-Grid Solar-Diesel Hybrid Power Generation System in a Remote Bangladesh

To relief the earth from extracting of her all the conventional energy and to keep her safe for our upcoming successor, the focus of power sector must be pointed to the utilization and development of renewable energy technology. As alternative energy sources, wind and solar energies can be used to supplement the conventional energy sources predominantly in remote localities of Bangladesh. This paper presents a feasibility study of renewable resources of Kutubdia, which is an offgrid remote island. Purpose of this paper is to design and simulation of an optimal mini-grid Solar-Diesel hybrid power generation system in a remote Bangladesh to satisfy the electrical energy demands in a reliable manner by HOMER ENERGY software. To ensure uninterrupted power supply due to the remittent nature of renewable resources, a diesel generator is added. This paper analyzes the optimal size of photovoltaic (PV) panel, inverter, rectifier, and battery with a fixed capacity diesel generator, electrical load with a certain random variability, fraction of renewable electricity, excess electricity, net present cost (NPC), annualized cost, fuel summary, performance of its different components, and environmental impacts. Evaluation of results shows that the hybrid energy system can deliver energy in a remote off-grid location with an acceptable cost.

Demand side management approach to rural electrification of different climate zones in Indian state of Tamil Nadu

This paper involves the hybrid power potential implementation in view of six climatic zones in Indian state of Tamil Nadu. An intertwined techno-economic feasible study and energy management analysis of Hybrid Renewable Energy System (HRES) has been proposed to cater to need of the electrical energy requirement in un-electrified village hamlets of Tamil Nadu. The HRES feasibility, size optimization, cost and sensitivity analyses are performed to satisfy the electrical energy requirements of the considered area. A combination of Demand Side Management (DSM) and optimum tilt solar panel approach has also been analyzed through HOMER Energy® simulation. The selection of HRES configuration is based on real-time data collected from six different climatic zones. The optimization results of the considered system are presented and compared with and without DSM strategy. The optimum planning of HRES is based on ranking scheme which includes technical and ecological aspects for sustainable development. In addition, to evaluate the most feasible consideration of the system, sensitivity analysis has been performed upon the load variation, biomass and diesel price too. The simulation results of the proposed HRES configuration can improve the renewable fraction and offer more employment opportunities to the local people, compared to the existing PV-DG-Battery HRES.

Standalone fuel cell generation system with different tracking techniques: economic analysis

The proton exchange membrane fuel cell (PEMFC) can be operated at different points such as the maximum power point (MPP) to extract maximum power and the maximum efficiency point (MEP) to operate at maximum efficiency. However, the different tracking techniques influence the cost of electricity (COE) of the fuel cell generation system. In this paper, the economic analysis of the PEMFC with the MPP tracking (MPPT) and MEP tracking (MEPT) techniques using the HOMER energy system analysis software is presented. A detailed comparison of the economic impact of the tracking techniques for ten load configurations of a standalone fuel cell generation system, which includes combined heat and power (CHP) loads is presented and discussed. Finally, based on economic considerations, a procedure to select a suitable tracking technique for particular requirements of the standalone PEMFC application is proposed. It is found that in the case of CHP configuration, the MPPT technique is the preferred technique to achieve low COE.

Electrification Planning with Focus on Hybrid Mini-grids – A Comprehensive Modelling Approach for the Global South

Electrification of rural areas is one of the major challenges in countries of the Global South. A proper electrification planning requires comprehensive electrification modelling to understand the least-cost supply options. Within this paper we apply a literature review on the requirements of comprehensive electrification modelling. This is extended by research on and testing of existing modelling tools (HOMER Energy, Network Planner, GEOSIM). This analysis reveals that still none of the existing tools can fulfill all requirements combining geospatial and detailed power system modelling especially for hybrid mini-grids. Thus we present our newly developed electrification modelling approach which overcomes identified gaps.

Análise técnica e financeira de usina híbrida eólica fotovoltaica

This study aimed to make a technical and financial analysis of a wind-photovoltaic hybrid power plant installed in the City of Caetite, BA, Brazil. The analysis aims to verify the influence of annual funding rate in the cost of installation and cost of the hybrid power generation plant. In this paper, it was used as a modeling tool the Homer Energy® software. According to the results, the solar irradiation and the average wind speed Caetite may favor the installation of hybrid plants. In the simulation, for a real rate of 1% per year, average wind speed and average irradiation Caetite, found the average cost would be equivalent to R$ 0.127 per kilowatt generated. For Caetite region posting an installation of 9 MW (megawatts) peak photovoltaic technology and 18 wind turbines VESTAS with a capacity of 1.65 MW each, that is, the total nominal installed capacity of 38.7 MW. It is estimated a cost of equivalent power generation to R$ 0.123 a kilowatt, representing the best result found among all displayed settings. The results show various configurations for wind and photovoltaic hybrid power plants installed in Caetite. Contributing to the understanding of the installation and power generation costs. Keywords: wind-photovoltaic power plants, Wind Power, Solar Energy, Power Generation

Abatement of air pollution at an aegean island port utilizing shore side electricity and renewable energy

The air pollutant emissions of the ships at port represent a small percentage of the overall emissions from shipping however they are concentrated in a small area. In Mytilene, Lesvos, the port is located within the city limits, resulting in air pollution, congestion and noise, especially during the tourist season. The aim of this study is to estimate the quantities of particulate matter and CO2 emitted by ships in the port of Mytilene and to explore the potential of shore side electricity to reduce the emissions. The emissions were estimated using the bottom–up methodology, based on the activity of the ships in the port (berthing, maneuvering). Simulation of renewable energy sources was made using Homer Energy microgrid simulation software. The results showed that between the 10th and 20th of August 2012, there were 40 calls of passenger ships, tankers and bulk carriers in the port of Mytilene, emitting 441kg of PM10 and 282 metric tonnes of CO2. About 63% of PM10 and 77% of CO2 were emitted at the berthing phase and the remaining during the maneuvering. These emissions could be reduced by providing electricity to the ships from a hybrid renewable energy system with wind turbines and photovoltaics, connected to the grid. Simulations showed that the total energy requirements of the ships in the port of Mytilene could be covered by four 1.5MW wind turbines combined with a 5MW photovoltaics. With this configuration, renewable energy will exceed the ships' electricity needs for most of the time in order not to increase the power station's load. The excess energy could be fed to the islands' grid, so a costly battery storage system is not necessary to handle the variations of alternative energy. In this way, a considerable reduction of the CO2 and PM10 emissions by the ships in the port occurs, providing a viable solution for a cleaner and healthier environment.

Isolated power system in Russia: A chance for renewable energies?

The Russian power system is diversified regionally and consists of one Unified Power System (UPS) and multiple isolated power systems. In the Russian Federation the policy on the use of renewable energies has been one of the most debated topics in recent years. In 2010, the Russian Renewable Energy Program was launched which aims to generate 4.5% of the entire electricity demand from renewable energy sources by 2020. These energy resources can significantly contribute to both the reduction of electricity generation costs in the Isolated Power Systems (IPS) and to the creation of new job opportunities. In this study an innovative methodology for the planning of isolated power systems is presented. The methodology is based on the Analytic Hierarchy Process (AHP) and on the software program HOMER Energy®. It considers the economic, social and environmental criteria for the optimal planning of isolated systems. A case study related to a small Siberian isolated power system is analyzed.

Design and simulation of a hybrid micro-grid for Bisheh village

In this paper, a gird-connected hybrid energy system for Bisheh village of environs the Khorramabad will be designed optimally with regard to the potential of wind and solar energy in this area. With annual average solar radiation of 5.521kWh/m 2 /day and annual average wind speed of 4.2 m/s, this village has a great potential of utilization of the renewable sources. Simulation has been done by HOMER ENERGY which is developed by the U.S. National Renewable Energy Laboratory. In order to achieve the most optimal design for power generation, the simulation of the mentioned micro-grid will be made for 6 different scenarios. With comparing the results of these simulations, it is indicate that the best scenario is designing the hybrid micro-grid connected to the main grid. Also sensitivity analysis will be perform based on various parameters such as interest rate, the price of purchasing power from the main grid, fuel price, wind speed, solar radiation, and air temperature and acquired results will compare together. By analyzing the results, we found that, the use of renewable resources is more economical than diesel generators when the fuel price is close to the world prices or interest rate is high. In addition, production of power will be more economical than purchasing power from the main grid by using diesel generators with renewable resources when price of purchasing power from the main grid is similar to the world prices, so under these conditions, micro-grid doesn’t have tend to purchasing power from the main grid.

Optimized Planning for Hybrid Micro-grid in Grid-connected Mode

The emergence of the Distributed Generation (DG) units along with their application in the distribution system level has led to the establishment of microgrids. microgrids are a part of the distribution network in which, in addition to the loads, there are micro sources operating in two modes, i.e. grid-connected mode and island also known as standalone mode. In the grid-connected mode, the load is supplied through local DG units, and if necessary, power is exchanged with the upstream grid, concerned as well. Considering the development of DG units technology in recent years which in turn, has led to the expansion of microgrid concept, microgrid planning meaning determining the capacities of local DG units assumes an extraordinary significance, taking the technical, economic and environmental considerations into account. This research tries to study the optimized planning for a grid-connected hybrid microgrid. The case study was conducted in Razi University in Kermanshah, Iran (34°23'Nlatitude and 47°6'E longitude). Due to the stochastic behavior of renewable energies based DG units, the uncertainties about the amount of generated power from these resources are considered using appropriate probability density functions. The problem is a Mixed Integer Non-linear Program (MINLP), to be solved by means of GAMS software. In order to bring about optimized results, microgrid simulation is processed in assorted scenarios, both in probabilistic and deterministic modes. In the end, the results are compared to those resulted from Homer Energy software. KeywordsOptimized Planning, Hybrid microgrid, Probability Functions, Uncertainty, Distributed Generation