Diesel System Research Articles

Multi-objective optimization minimizing cost and life cycle emissions of stand-alone PV–wind–diesel systems with batteries storage

This paper describes an application of the Strength Pareto Evolutionary Algorithm to the multi-objective optimization of a stand-alone PV–wind–diesel system with batteries storage. The objectives to be minimized are the levelized cost of energy (LCOE) and the equivalent carbon dioxide (CO 2) life cycle emissions (LCE). Each solution of the Pareto front is a possible solution for the PV–wind–diesel-batteries system, which can supply the load, but each one has a different LCOE and LCE. Some solutions have low LCOE values, but high LCE values, and vice versa. Results show that the photovoltaic (PV) generator is the most important source of electrical energy for stand-alone systems in Spain and Southern Europe, not only environmentally, but also economically. In some cases, PV is almost the only source of energy, as some solutions of the best Pareto front do not include wind turbines and diesel generators run only a few hours during the year.

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.

The reactive oxidant potential of different types of aged atmospheric particles: An outdoor chamber study

The reactive oxygen species (ROS) potential of aged diesel exhaust particulate matter (PM) and other aged aerosol systems in the presence and absence of an urban hydrocarbon environment was assessed. Experiments were performed in a 274 m 3 dual outdoor Teflon film chamber. Filter samples were taken to assess the oxidant generation associated with PM by an optimized dithiothreitol (DTT) method. Diesel exhaust PM had a higher ROS response when it was in the presence of an urban hydrocarbon mixture and was associated with significant O 3 production. For all the aged dilute diesel systems, ROS expression increased by a factor of 2–4 over fresh diesel particles. Other particle systems were also investigated. A low ROS was observed in most of the nighttime experiments, including the nighttime aerosols from SO 2 with O 3 and SO 2 aged by itself. However, when all the systems were compared, aged diesel exhaust tended to express very high ROS potentials, with secondary organic aerosols from an α-pinene + toluene + an urban HC mixture giving the highest ROS response. ► ROS from diesel particles increased by a factor of 2–4 as they aged in sunlight. ► Increases in Diesel ROS were associated with PAH decay and increases in SOA. ► ROS from toluene and α-pinene SOA formation were among the highest observed.

Performance of Statcom in an Isolated Wind–Diesel Hybrid Power System

The paper presents study of an isolated hybrid power system using a proportional integral (PI) controller with a static synchronous compensator (STATCOM) for reactive power control to maintain constant voltage at the generator terminals. The renewable energy sources such as solar, wind, bio-mass, etc. that are intermittent in nature use induction generator as electro-mechanical device for conversion of mechanical to electrical energy, but reactive power is required for the operation of the induction generator in addition to the reactive power required by the load. The synchronous generator used in hybrid system for generating power through diesel system is supplying reactive power to the system partially; therefore, another source of reactive power is required to fulfill this demand. The paper also shows the dynamic performance of the hybrid system both for constant and variable slip conditions and 1% step change in reactive power load by considering wind–diesel hybrid power system as an example.

Potential for electrification from biomass gasification in Vanuatu

Abstract At least 170,000 rural people in the Pacific-island nation Vanuatu (approximately 70% of the country’s population) live without reliable access to electricity. The few rural households that do consume electricity incur high prices for imported diesel fuel ($2–3/liter). Thus, there is an important role in Vanuatu for expanding cost-competitive, non-diesel alternatives for electricity generation. Informed by an interdisciplinary data synthesis and an extensive series of field interviews in Vanuatu, this paper analyzes the potential for converting reportedly obsolete timber plantation land into a dedicated feedstock supply system for new small-scale biomass gasifiers. The analysis draws upon geographic mapping of electricity demand and feedstock supply, a historical assessment of Vanuatu’s forest plantations, a techno-economic evaluation of investment in 10 kW and 30 kW gasifiers, and a discussion of important social-institutional factors. This analysis identifies up to 13 geographic matches between areas of rural electricity demand and potential feedstock supply. In addition, financial modeling suggests that the levelized cost of electricity from gasification is competitive (relative to diesel systems) given capacity factors of 15–40% or greater (corresponding to a cost of $1.60/kWh or less). Further research is recommended to examine the socioeconomic and ecological aspects of feedstock plantation establishment in Vanuatu.

Study of an isolated wind–diesel hybrid power system with STATCOM by incorporating a new mathematical model of PMIG

SUMMARYThis paper presents automatic reactive power control of an isolated wind–diesel hybrid power system. A synchronous generator is used for power generation from diesel and a permanent‐magnet induction generator (PMIG) is used for electric power generation from wind turbine. A new mathematical model is developed to incorporate the effect of permanent‐magnet of the PMIG in the generation of reactive power. To eliminate the gap between reactive power generation and demand, a variable source of reactive power is used such as static synchronous compensator (STATCOM). A study on the wind–diesel system is conducted based on small signal analysis by considering IEEE type‐1 excitation system for the synchronous generator. The paper also shows the dynamic performance of the hybrid system both for constant and variable slip conditions and 1% step change in reactive power load. Copyright © 2011 John Wiley & Sons, Ltd.

Modelling and simulation of a high penetration wind diesel system with battery energy storage

Wind Diesel Hybrid Systems (WDHS) are isolated power systems which combine Diesel Generators (DG) with Wind Turbine Generators (WTG). Depending on the generators which are supplying, high penetration (HP) WDHS have three operation modes: Diesel Only (DO), Wind Diesel (WD) and Wind Only (WO). The HP-WDHS presented in this article consists of a Diesel Engine (DE), a Synchronous Machine (SM), a Wind Turbine Generator, the consumer load, a Ni-Cd Battery based Energy Storage System (BESS) and a Dump Load. The DE can be engaged (DO and WD modes) or disengaged (WO mode) from the SM by means of a clutch. All the models of the previously mentioned components are presented and the performance of the WDHS has been tested through dynamic simulation. Simulation results with graphs for the frequency and voltage of the isolated power system, active powers generated/absorbed by the different elements and the battery voltage/current/state of charge are presented for a load change in WO mode and for the transition from WO to WD mode in order to substitute a supplying BESS for the DE as the active power source.

Smooth Synchronisation and Power Sharing Schemes for High Penetration Wind Diesel Hybrid Remote Area Power Systems

The paper proposes synchronisation and power sharing schemes for fast connection and smooth operation of high penetration wind-diesel hybrid systems. The synchronisation is realised by controlling the power electronic interface of the wind energy systems rather than the classical diesel engine synchronisation scheme. The power sharing between the diesel and wind systems is achieved by a modified power-frequency droop control method. The proposed schemes are tested on a simulated hybrid system to demonstrate their effectiveness.

Density, Excess Volumes, and Partial Volumes of Binary Mixtures of Soybean Biodiesel + Diesel and Soybean Biodiesel + n-Hexadecane at Different Temperatures and Atmospheric Pressure

Densities, ρ, of binary mixtures of diesel + soybean biodiesel and n-hexadecane + soybean biodiesel have been measured as a function of the composition at different temperatures (293.15, 313.15, 333.15, 353.15, and 373.15) K and atmospheric pressure, over the entire composition range, using an Anton Paar SVM 3000 oscillating U-tube densimeter. The excess molar volume, VE, and excess partial molar volume, V̅E, of the binary mixtures were calculated from the density data. These data have been correlated using the Redlich−Kister type function in terms of mass fraction (w), with a maximum standard deviation of 0.152 cm3·mol−1. The excess volumes are positive for the soybean biodiesel + diesel system. The values of the excess volume for the system soybean biodiesel + n-hexadecane are also positive and an inversion of sign in VE is observed at higher molar fractions of soybean biodiesel (around x1 = 0.60 to 0.80). The excess partial volume at infinite dilution has been also calculated.

Simulation of an isolated Wind Diesel System with battery energy storage

The subject of this paper is to present the modelling and simulation of an isolated Wind Diesel Hybrid System (WDHS) comprising a Diesel Generator (DG), a Wind Turbine Generator (WTG), the consumer Load, a Ni–MH battery based Energy Storage System (BESS) and a Dump Load (DL). The BESS consists of a battery bank and a power converter which performs the DC/AC conversion to interface the battery with the isolated grid. The Ni–MH battery high power capability, low maintenance, resistance to abuse and absence of hazardous substances make it the best choice for WDHS. The modelling of the previously mentioned components is presented and the performance of the WDHS is tested through dynamic simulation. Simulation results with graphs for the frequency and voltage of the Isolated Power System, active powers generated/absorbed by the different elements and the battery voltage/current/state of charge are presented for load and wind speed changes. The simulation results for the BESS/no BESS cases are compared and show a remarkable improvement in the system dynamics due to the use of the BESS.

Techno-Economic Potential of Retrofitting Diesel Power Systems with Hybrid Wind-Photovoltaic-Diesel Systems for Off-Grid Electrification of Remote Villages of Saudi Arabia

Recent climatic anomalies such as hot summers, cold winters, hurricanes, and cyclones are all reflections of global warming due to burning of fossil fuels. To combat unprecedented global warming and to mitigate future energy challenges, there is worldwide interest in utilization of renewable sources of energy such as solar-photovoltaic (solar-PV) and wind energy. Other driving forces paving avenue for renewable energy include rapid escalation in oil prices, growing concerns regarding depletion of oil/gas reserves, etc. Retrofitting of diesel systems with hybrid wind-PV-diesel systems is being widely disseminated to reduce diesel fuel consumption and to minimize atmospheric degradation. One of the potential market for deployment of hybrid systems is in remote locations which are driven by diesel generators. The Kingdom of Saudi Arabia (KSA) has a number of remote villages scattered all over the Kingdom. The aim of this study is to analyze wind speed and solar radiation data of Rafha, KSA, and to assess the technical and economic potential of hybrid wind-PV-diesel power systems to meet the load requirements of a typical remote village Rawdhat Bin Habbas (RBH) with annual electrical energy demand of 15,943 MWh. Rafha is located near RBH. The monthly average wind speeds range from 2.99 m/s to 4.84 m/s at 10 m height. The monthly average daily global solar radiation ranges from 3.04 to 7.3 kWh/sq.m. The hybrid systems simulated consist of different combinations of 600 kW wind machines, PV panels, supplemented by diesel generators. National Renewable Energy Laboratory's (NREL) Hybrid Optimization Model for Electric Renewables (HOMER) software has been used to perform the techno-economic study. The simulation results indicate that for a hybrid system comprising of 1.2 MW wind farm capacity (two 600 kW units, 50 m hub-height) and 1.2 MW of PV capacity together with 4.5 MW diesel system (three 1.5 MW units), the renewable energy fraction with 0% annual capacity shortage is 24% (10% wind + 14% PV). The cost of generating energy (COE) from this hybrid wind-PV-diesel system has been found to be 0.118 $/kWh (“assuming diesel fuel price of 0.1$/l”). The study exhibits that for a given hybrid configuration, the number of operational hours of diesel generators decreases with increase in wind farm and PV capacity. Attention has also been focused on wind/PV penetration, unmet load, excess electricity generation, percentage of fuel savings and reduction in carbon emissions (relative to diesel-only situation) of different hybrid systems, cost breakdown of wind-PV-diesel systems, COE of different hybrid systems, etc.

Economic Analysis of Hybrid Renewable Model for Subtropical Climate

Current power systems create environmental impacts due to utilization of fossil fuels, especially coal, as carbon dioxide is emitted into the atmosphere. In contrast to fossil fuels, renewable energy offers alternative sources of energy which are in general pollution free, technologically effective and environmentally sustainable. There is an increased interest in renewable energy, particularly solar and wind energy, which provides electricity without giving rise to carbon dioxide emissions. This paper presents economic analysis of a renewable hybrid system for a subtropical climate and also investigated the impact of renewable energy sources to the existing and future smart power system. The daily mean global solar irradiance and three hourly mean wind speed have been collected from the Rockhampton Aero Weather Station, Queensland (RAWS), Australia for this study. Hybrid Optimization Model for Electric Renewable (HOMER), a computer model developed by National Renewable Energy Laboratory (NREL) has been used to perform comparative analysis of solar and wind energy with diesel and hybrid systems. Initially total net present cost (NPC), cost of energy (COE) and the renewable fraction (RF) have been measured as performances metrics to compare the performances of different systems. For better optimization, the model has been refined with sensitivity analysis which explores performance variations due to wind speed, solar irradiation and diesel fuel prices. From the simulation, it is shown that there are a number of factors that impact the integration and performance of renewable energy sources to the power systems.

An Online Control Algorithm for Application of a Hybrid ESS to a Wind–Diesel System

Energy storage systems (ESSs) can be applied to mitigate some of the negative impacts associated with a variable power generation source such as wind energy. The control of ESS power must be accomplished over numerous time frames to meet system objectives and respect ESS capacity constraints. This paper proposes a two-level ESS control structure for use with a wind-diesel system, which is suitable for online implementation. The control is developed to coordinate power delivered from the two ESS levels in order to minimize diesel fuel consumption and limit up/down rates of the diesel plant. Different control modes are evaluated by simulation, and a subset of the results are validated using a hardware-in-the-loop representation. The controller that combines all three functionalities-minimizing dump load, limiting intrahour diesel ramp rates, and maximizing ESS utilization-demonstrates superior performance as measured by defined metrics and is proven to work online.

Energetic, environmental and economic aspects of a hybrid renewable energy system: a case study

In this study, the solar irradiation and wind speed data of Balikesir in Turkey are analyzed to assess the techno-economic viability and environmental performance of a hybrid power system. Energy is estimated for a typical commercial poultry house, and a system is then designed to satisfy the load demand. As hybrid Optimization Model for Electric Renewable (HOMER) software is used for the simulation of four respective cases: Diesel only, photovoltaic (PV)--diesel--battery, wind--diesel--battery and photovoltaic--wind--diesel--battery. We also evaluate the cost, environmental advantages and benefit of the demand-side management (DSM) when renewable hybrid energy options are applied to the poultry farming. By implementing light control system and high-efficiency fans (with about 20% efficiency increase), annual electricity consumptions can be reduced by 15% with DSM. When DSM was applied to the cost of energy, certain parameters including unmet electric load, excess electricity and greenhouse gas emissions are calculated for each case. Greenhouse gas emissions are also investigated for the hybrid energy system (by integrating PV and wind turbine only into diesel system). The hybrid system thus reduces CO 2 emissions from 21.8 to 10t, particulate matter (PM) from 4.1 to 1.9 kg, NO x from 0.421 to 0.221t. A break-even analysis is performed to decide the optimum distance where the hybrid energy system is more economical than the extension of the transmission line. Consequently, the results indicate that installation of the hybrid energy system is more economical than the conventional electricity network when the distance is more than 3.21 and 3.13 km for PV--wind--diesel--battery and wind--diesel--battery, respectively. Copyright The Author 2010. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com, Oxford University Press.

Reactive Power Compensation of Isolated Wind-Diesel Hybrid Power Systems with STATCOM and SVC

The use of the isolated hybrid power systems is being popular due to the continuous increasing gap between demand and supply of conventional energy sources and intermittent nature of non-conventional energy sources. Normally, the non-conventional energy source such as wind have induction generator to generate electricity but induction generators require reactive power for its operation and this demand is continuously changing by the variation of load and wind power. The synchronous generator used in hybrid system for generating power through diesel system is supplying reactive power to the system partially; therefore, another source of reactive power is required to fulfill this demand. In this paper, the static VAR compensator (SVC) and static synchronous compensator (STATCOM) using a proportional-integral controller (PI) are used as reactive power compensator. The dynamic performance of SVC and STATCOM are investigated for wind-diesel and wind-diesel- microhydro power systems ate constant slip operation of induction generators. The results show that the STATCOM is a better option than that of SVC for reactive power control of the hybrid system.

National Grid, Diesel, and Photovoltaic Power Generation Systems in Jordan: An Engineering and Economical Evaluation

The energy sector in Jordan depends heavily on imported oil and gas products and as a result, this energy policy put the country in tough economic situations and slowed down industrial growth in the last 15 years. This situation is worsened by the dramatic increase in crude oil prices worldwide and the increased demand on energy consumption. Therefore, it became clear that a new power generation system needs to be considered as an alternative for the national grid electricity and the diesel power generation systems. In this study, three power generation systems were compared: the national grid electricity system, diesel power generation system, and photovoltaic power generation system. From the models built for this study, it was found that the solar energy utilized to generate electricity by using photovoltaic solar panels can provide an alternative power source with lower annual cost than the diesel power generation system. The data analysis shows that the national grid still provides the lowest annual cost compared to the other considered systems in this study based on the current electricity tariff and energy policy that charges high taxes on photovoltaic systems. Therefore, it is strongly recommended to change the energy policy in Jordan by lowering the customs and tax charges by at least 35% on photovoltaic panels, solar batteries, regulators and invertors and any other components that are necessary to build a complete photovoltaic system.

Gain Scheduling Control of a Combined Diesel or Gas Ship Propulsion System with Parameter-Dependent Delay

This paper presents the main features of a combined diesel or gas ship propulsion system and a control strategy to be applied to its velocity channel. Operating limits, saturations and parameter-dependent delays make the system dynamic behavior highly nonlinear. The main objective is to control the ship velocity by using identification techniques and a combination of Smith predictor with a gain scheduling control method. The aim is to meet the specified time-domain performance with disturbance rejection over the entire operating range. Numerical results clearly show the advantages of using the proposed control technique.

Distributed Generation to Reduce Carbon Dioxide Emissions: A Case Study for Residential Sector in Oman~!2009-11-03~!2010-03-13~!2010-06-09~!

The paper presents a case study in Oman to reduce the CO2 emission by diesel-photovoltaic based distributed power system feeding to a house located in remote area. Model of a hybrid power system comprising of a photovoltaic module, along with a diesel generator and essential auxiliary devices is proposed. The actual average solar radiation and residential load data, collected from the meteorological department and local utility office are used in this case study. The simulation results carried out using HOMER software indicate that the proposed hybrid system is attractive to reduce CO2 emission by 38% when compared to the diesel system alone, and by 2.67 % compared to the main interconnected system. The study also includes operational and per unit energy cost estimates. It is seen that the diesel-photovoltaic hybrid system is attractive in terms of operational costs, which is lower by 29.44% compared to the diesel system; while per unit energy cost is 12.08% lower. It may be noted that the cost estimates arrived at for main interconnected system are better in terms of per unit energy cost, which is lower by 8.43 % compared to the proposed hybrid system, while it is not attractive in terms of CO2 emissions. The Kyoto Protocol provides various mechanisms like joint implementation, clean development mechanism and international emission trading that enable countries to acquire GHG reduction credits. The evaluation and deployment of carbon credit is a key component to mitigate the growth in concentration of GHG. Prabhakant and Tiwari (2) have carried out an analysis to determine the carbon credits earned using standalone solar PV system which is encouraging and cost effective than conventional power generation. The other viable option to curb the carbon emission is substantial use of renewable energy along with the conventional resources. The paper presents a case study to reduce the GHG by proposing a Diesel-Photovoltaic Hybrid System (D-PVHS) feeding to a house located in remote area. The reminder of this paper is organised as follows. Second section presents the historical data of CO2 emission and daily residential power demand. Section III estimates the emission factor and energy cost of Main Interconnected System (MIS) feeding to the residential sector. Section IV describes the potential of renewable energy in the Oman. The model development is described in Section V. The application of this case study is explained in section VI. Results and discussion are described in section VII while conclusions of the study are presented in section VIII.

Economic feasibility of autonomous hybrid wind–diesel power systems for residential loads in hot regions: a step to mitigate the implications of fossil fuel depletion

Today, energy occupies a pivotal position around which all socio-economic activities revolve. No energy means no life, and supply of energy in a cheap, plentiful, long-sustainable and environmentally safe form is a boon for everyone. In the light of rising cost of oil and fears of its exhaustion coupled with increased pollution, the governments worldwide are deliberating and making huge strides to promote renewable energy sources such as wind. Integration of wind machines with the diesel plants is pursued widely to reduce dependence on fossil-fuel-produced energy and to reduce the release of carbon gases that cause global climate change. The literature indicates that commercial/residential buildings in the Kingdom of Saudi Arabia (KSA) consume an estimated 10–40% of the total electric energy generated. The aim of this study is to analyse wind-speed data of Dhahran (East-Coast, KSA) to assess the economic feasibility of utilising autonomous hybrid wind–diesel power systems to meet the electrical load of 100 typical residential buildings (with annual electrical energy demand of 3512 MWh). The monthly average wind speeds range from 3.3 to 5.6 m/s. The hybrid systems simulated consist of different combinations of 600 kW commercial wind machines supplemented with diesel generators. The National Renewable Energy Laboratory's hybrid optimisation model for electric renewables software was employed to perform the techno-economic analysis. The simulation results indicate that for a hybrid system comprising 600 kW wind capacity together with a 1.0 MW diesel system (two 500 kW units), the wind penetration (at 50 m hub-height, with 0% annual capacity shortage) is 26%. The cost of generating energy (COE, $/kWh) from this hybrid wind–diesel system was found to be 0.070 $/kWh (assuming diesel fuel price of 0.1 $/l). The study exhibits that for a given hybrid configuration, the number of operational hours of diesel generator sets (gensets) decreases with an increase in the wind-farm capacity. Concurrently, emphasis has also been placed on wind penetration, un-met load, effect of hub-height on energy production and COE, excess electricity generation, percentage fuel savings and reduction in carbon emissions (relative to diesel-only situation) of different hybrid systems, cost breakdown of wind–diesel systems, COE of different hybrid systems, etc.

Performance analysis of hybrid photovoltaic/diesel energy system under Malaysian conditions

Standalone diesel generating system utilized in remote areas has long been practiced in Malaysia. Due to highly fluctuating diesel price, such a system is seemed to be uneconomical, especially in the long run if the supply of electricity for rural areas solely depends on such diesel generating system. This paper would analyze the potential use of hybrid photovoltaic (PV)/diesel energy system in remote locations. National Renewable Energy Laboratory’s (NREL) HOMER software was used to perform the techno-economic feasibility of hybrid PV/diesel energy system. The investigation demonstrated the impact of PV penetration and battery storage on energy production, cost of energy and number of operational hours of diesel generators for the given hybrid configurations. Emphasis has also been placed on percentage fuel savings and reduction in carbon emissions of different hybrid systems. At the end of this paper, suitability of utilizing hybrid PV/diesel energy system over standalone diesel system would be discussed mainly based on different solar irradiances and diesel prices.