Browsing by Author "Perera, ATD"

Now showing 1 - 20 of 21

item: Article-Full-text
Converting existing Internal Combustion Generator (ICG) systems into HESs in standalone applications
(Elsevier, 2013) Perera, ATD; Attalage, RA; Perera, KKCK; Dassanayake, VPC
Expanding existing Internal Combustion Generator (ICG) systems by combining renewable energy sources is getting popular due to global concern on emission of green house gases (GHG) and increasing fossil fuel costs. Life cycle cost, initial capital cost (ICC), power supply reliability of the system, and GHG emission by ICG are factors to be considered in this process. Pareto front of Levelized Energy Cost (LEC)– Unmet Load Fraction (ULF)–GHG emission was taken in this study for four different expansion scenarios. Furthermore, Pareto front of ICC–LE–ULF was taken for three different expansion scenarios in order to analyze the impact of renewable energy integration. The results clearly depict that characteristics of the Pareto front varies with the scale of expansion and objectives taken for the optimization. A detailed analysis was conducted for a scale up problem with a 4 kVA ICG by using the Pareto fronts obtained.
item: Article-Full-text
Designing standalone hybrid energy systems minimizing initial investment, life cycle cost and pollutant emission
(Elsevier, 2013) Perera, ATD; Attalage, RA; Perera, KKCK; Dassanayake, VPC
HES (hybrid energy system)s are becoming energy systems of choice for standalone applications due to ever increasing fuel costs and global concern on GHG (Green House Gas) emissions. However, it is difficult to justify the higher ICC (Initial Capital Cost) of renewable energy components, especially for rural electrification projects in developing countries. This paper illustrates the modeling and simulation of HESs, and multi-objective optimization carried out in order to support decision-making in such instances. LEC (Levelized Energy Cost), ICC and GHG emission were taken as objective functions in the optimization and the sensitivity of market prices and power supply reliability was further evaluated. Results depict that Pareto front of LEC, ICC and GHG emission can be simplified as a combination of ICC eLEC and LECeGHG emission Pareto fronts making the decision-making process simpler. Gradual integration of renewable energy sources in a number of design stages is proposed for instances where it is difficult to bear the higher ICC. Finally, importance of planning integration of renewable energy sources at early design stages of the project is highlighted in order to overcome the difficulties that need to be faced when coming up with the optimum design.
item: Conference-Abstract
Determining wind turbine capacity for expansion of off grid internal combustion generators (ICG) system; why it becomes challenging?
Perera, ATD; Wickremasinghe, DMIJ; Mahindarathna, DVS; Attalage, RA; Perera, KKCK; Bartholameuz, EM
Combining renewable energy sources to Internal Combustion Generator (ICG) systems for standalone applications is becoming popular due to higher depletion rate of fossil fuel resources and global concerns on Green House Gas (GHG) emission. In this study, Hybrid Energy System (HES) modeling and simulation was done in order to investigate the impact of Wind Turbine Capacity (WTC) for expansion of such ICG systems. For that, ε- multi objective optimization was used to analyze the effect of varying WTC to Levelized Energy Cost (LEC) and ICG energy output. Obtained results show the importance of multi criterion analysis instead of classical cost optimization in expanding existing ICG systems in a cost effective environment friendly manner.
item: Article-Full-text
Electrical hubs: An effective way to integrate non-dispatchable renewable energy sources with minimum impact to the grid
(Elsevier, 2017) Perera, ATD; Nik, VM; Mauree, D; Scartezzini, J-L
A paradigm change in energy system design tools, energy market, and energy policy is required to attain the target levels in renewable energy integration and in minimizing pollutant emissions in power generation. Integrating non-dispatchable renewable energy sources such as solar and wind energy is vital in this context. Distributed generation has been identified as a promising method to integrate Solar PV (SPV) and wind energy into grid in recent literature. Distributed generation using grid-tied electrical hubs, which consist of Internal Combustion Generator (ICG), non-dispatchable energy sources (i.e., wind turbines and SPV panels) and energy storage for providing the electricity demand in Sri Lanka is considered in this study. A novel dispatch strategy is introduced to address the limitations in the existing methods in optimizing grid-integrated electrical hubs considering real time pricing of the electricity grid and curtailments in grid integration. Multi-objective optimization is conducted for the system design considering grid integration level and Levelized Energy Cost (LEC) as objective functions to evaluate the potential of electrical hubs to integrate SPV and wind energy. The sensitivity of grid curtailments, energy market, price of wind turbines and SPV panels on Pareto front is evaluated subsequently. Results from the Pareto analysis demonstrate the potential of electrical hubs to cover more than 60% of the annual electricity demand from SPV and wind energy considering stringent grid curtailments. Such a share from SPV and wind energy is quite significant when compared to direct grid integration of non-dispatchable renewable energy technologies.
item: Conference-Abstract
Evolutionary multi objective optimization to optimize waste to energy network
Perera, ATD; Kuruppumullage, DNS; Nissank, NAID; De Alwis, AAP
Energy recovery through thermal conversion of municipal solid waste is been considered as a potential waste management technique and solution to the ever increasing energy demands. In order to evaluate the feasibility of this phenomena energy flow, material and cash modeling is done for three cases i.e. direct thermal conversion of waste, thermal conversion through Residue Derived Fuel (RDF) and landfilling. Further, Pareto multi objective optimization was performed considering Net Present Value (NPV) and landfilling capacity using evolutionary multi objective optimization. Results clearly depict, that non-linear fluctuations of objective functions are having a significant impact on Pareto front which has not being highlighted in previous studies.
item: Conference-Abstract
Feasibility study on solar photovoltaic Office Air Conditioning in Sri Lanka
(2011) Perera, KAEK; Kollure, KAL; Prasad, WAKSS; Perera, PABAR; Perera, ATD; Perera, KKCK
Due to the rapid depletion of fossil fuel resources and global concern on Green House Gas emissions, sustainable energy technologies have become important in Heating, Ventilation and Air Conditioning (HVAC) systems in buildings. As a result, much focus is given on research and application based on solar powered HVAC, in various parts of the world. Such initiatives are of timely importance in Sri Lankan context due to the availability of good solar energy potential. In this work, an existing air conditioning system for an office building of 51m~ in Sri Lanka was taken into study. An economic evaluation was performed using HOMER (Version 2.68 beta) to assess the feasibility of using Solar PV (SPV) to power the air conditioning system. The results show that under present circumstances, the Levelized Cost of Energy (COE) of the optimized photovoltaic stand alone system lies far above that of the grid powered. Lt further depicts that grid integration would bring down the COE of the SPV system closer to the range of the main grid. Hence in current conditions, grid integration is the way forward for SPV assisted air conditioning in Sri Lanka.
item: Conference-Extended-Abstract
How does the Internal generator capacity and power supply reliability affects hybrid energy system sizing?
(2010) Perera, ATD; Wickremasinghe, DMIJ; Mahindarathna, DVS; Attalage, RA; Perera, KKCK; Bartholameuz, EM
Combining renewable energy sources to Internal Combustion Generator (ICG) systems for standalone applications is becoming popular due to higher depletion rate of fossil fuel resources and global concerns on green house gas emission- Modeling, simulation and optimization of such Hybrid Energy System (HES) was done in this study in order to investigate the impact of ICG and wind turbine capacity to Levelized Energy Cost (LEC)j and ICG Energy produced, further evolutionary e-multi objective optimization wets used to analyze the effect of unmet load allowance to I.EC and ICG energy produced in such scenarios Obtained results were compared with HOMER (existing software based on enumerative method); which shows that the Wasted Renewable Energy (WRE) increases with the reduction of ICG capacity increasing system sizing which could be reduced by a large fraction with slight allowance for unmet load.
item: Article-Full-text
A hybrid tool to combine multi-objective optimization and multi-criterion decision making in designing standalone hybrid energy systems
(Elsevier, 2013) Perera, ATD; Attalage, RA; Perera, KKCK; Dassanayake, VPC
Hybrid energy systems (HESs) are becoming popular for standalone applications due to global concern regarding green house gas (GHG) emissions and depletion of fossil fuel resources. Research in the optimal design of HESs is ongoing, with numerous optimization techniques giving special emphasis to Pareto optimization, incorporating conflicting objectives. The subsequent decision-making process including the non-dominant set of solutions has yet to be addressed. This work focuses on combining multi-objective optimization with a multi-criterion decision making (MCDM) technique to support decision makers in the process of designing HESs. Four different objectives, i.e., levelized energy cost (LEC), unmet load fraction, wasted renewable energy (WRE) and fuel consumption are used to obtain the Pareto front. A decision support tool based on Fuzzy TOPSIS and level diagrams is proposed to analyze the Pareto front and support the subsequent decision-making activity. A case study is used to illustrate the applicability of the proposed method. The study shows that the novel method is useful when determining the relative weights of objectives, providing a detailed picture of the objective space to the designer when coming up with the optimum system. The technique proposed in this study can be further extended to analyze similar problems in energy system design where MCDM is necessary after multi-objective optimization.
item: Article-Abstract
Impact of building architecture on indoor thermal comfort level : a case study at University of Moratuwa, Sri Lanka
Nissanka, NAID; Perera, ATD; Attalage, RA
With ever-increasing prices of energy, designing energy efficient buildings has become vital. which demands multidisciplinary effort including architectural and engineering aspects since the early designing stage to day to day operation. Thermal comfort level of two such energy efficient buiIdings designed to facilitate general activities of the university are considered in this study. Lumped Mass Thermal (LMT) model was used to evaluate the net heat gain to the building through solar heating, internal heat generation etc. Effect of the building orientation, cross ventilation and special architectural aspects such as courtyards, grill design etc were evaluated using the same model. Hourly dry bulb temperature, wet bulb temperature, humidity level and solar irradiation level of six selected locations of the two buildings throughout the day were taken to validate the model. Finally, field study was carried out based on ASHRAE 55 standards with 50 selected occupants in each building. Obtained results from the field study were used to derive the human sensational scale using Predictive Mean Vote (PMV) index, which agrees with the results obtained by the LMT model.
item: Article-Full-text
An integrated approach to design site specific distributed electrical hubs combining optimization, multi-criterion assessment and decision making
(Elsevier, 2017) Perera, ATD; Nik, VM; Mauree, D; Scartezzini, J-L
An integrated approach is presented in this study to design electrical hubs combining optimization, multi-criterion assessment and decision making. Levelized Energy Cost (LEC), Initial Capital Cost (ICC), Grid Integration Level (GI), Levelized CO2 emission (LCO2), utilization of renewable energy, flexibility of the system, loss of load probability (LOLP) are considered as criteria used to assess the design. The novel approach consists of several steps. Pareto analysis is conducted initially using 2D Pareto fronts to reduce the dimensions of the optimization problem. Subsequently, Pareto multi objective optimization is conducted considering LEC, GI and ICC which were identified as the best set of objective functions to represent the design requirements. Next, fuzzy TOPSIS and level diagrams are used for multi-criterion decision making (MCDM) considering the set of criteria and the boundary matrix that represents the design requirements of the application. Pareto analysis shows that 5D optimization problem can be reduced to a 3D optimization problem when considering LEC, ICC and GI as the objective functions. Finally, results obtained from the case study shows that the novel method can be used design distributed energy systems considering a set of criteria which is beyond the reach of Pareto optimization with different priority levels.
item: Article-Abstract
A multi criterion analysis for renewable energy integration process of a standalone hybrid energy system with internal combustion generator
Perera, ATD; Madusanka, AN; Attalage, RA; Perera, KKCK
Integrating renewable energy into standalone Internal Combustion Generator (ICG) systems is an economical and eco-friendly option. However, previous studies demonstrate the difficulties in replacing the ICGs completely by using Solar PV (SPV) and wind energy with a dispatchable energy storage. This makes it interesting to analyze the limitations in integrating the SPV and wind energy into Hybrid Energy System. A multi criterion analysis is presented in this study, considering Levelized Energy Cost, Loss of Load Probability, and Fuel Consumption varying the scale of the ICG capacity to attain aforementioned objective. Changes in the system design with the integration of the SPV and wind energy were analyzed using Pareto multi-objective optimization considering Renewable Energy Capacity as an objective function. Sensitivity of the ICG capacity on optimum Renewable Energy Technology, role of the ICG in improving system reliability, etc., were subsequently analyzed. The results depict that the ICG capacity notably influence to the balance between wind and SPV capacity. An increase in the ICG capacity does increase the contribution from dispatchable energy source in most of the scenarios. Furthermore, it facilitates to amalgamate highly fluctuating renewable energy sources at a relatively low cost. This makes it inevitable to replace ICG with non-dispatchable renewable energy sources and energy storage.
item: Thesis-Abstract
Multi criterion decision making based on techno-economical optimization of stand-alone hybrid energy systems
(2014-08-12) Perera, ATD; Attalage, RA; Perera, KKCK; Dassanayake, VPC
Hybrid Energy System (HES)s areincreasingly becoming popular for standalone electrification due to global concerns on GHG emissions and higher depletion of fossil fuel resources. Simultaneously research work on optimal design of HESs has also made much progess based on progress with numerous optimization techniques while giving special focus to Pareto optimization considering conflicting objectives. This study comes up with a novel evolutionary algorithm to optimize HESs based on ε- dominance technique. Mathematical modeling of energy flows, cash flows, GHG emissions were carried out in order to support the optimization. Pareto analysis was conducted for two different cases where former analyzes a novel design of a HES and latter analyzes a conversion of existing Internal Combustion Generator (ICG) into a HES in the expansion process. The Levelized Energy Cost (LEC), annual fuel consumption and Initial Capital Cost (ICC) were considered to be objective functions in the first analysis. A sensitivity analysis was followed the mathematical optimization in order to evaluate the impact of power supply reliability on the Pareto front. Furthermore, sensitivity of fuel cost and renewable energy component cost on Pareto front was also investigated considering the present dynamic condition of energy market. LEC, power supply reliability and added renewable energy capacity were taken as objectives to be optimized in the second case. Sensitivity of ICG capacity on the Pareto front was also taken into discussion. Pareto analysis clearly elements such as LEC, power supply reliability and fuel consumption are conflicting to each other. Therefore it is essential to perform multi criterion analysis in order to assist decision making. In order to assist decision making, Fuzzy-TOPSIS (a multi criterion decision making technique) was combined with Pareto optimization. For that, multi objective optimization was carried out considering Levelized Energy Cost (LEC), unmet load fraction, Wasted Renewable Energy (WRE) and fuel consumption as elements in the objective functions to generate non-dominant set of alternative solutions. Pareto front obtained from the optimization was ranked using Fuzzy-TOPSIS technique and Level Diagrams were used to support this process
item: Conference-Abstract
Multi objective optimization and multi criterion decision making in expanding existing standalone energy systems combing renewable energy sources
Perera, ATD; Sirimanna, MPG; Attalage, RA; Perera, KKCK; Dassanayake, VPC
Hybrid Energy Systems (HESs) are becoming popular for standalone applications due to price volatility of fossil fuel resources and global concern on GHG emission. Expansion of an existing standalone Internal Combustion Generator (ICG) system while incorporating renewable energy sources is taken in to discussion in this work which converts ICG systems into a HES. In order to achieve this, a standalone HES consisting of wind turbines, Spy panels, batter bank, ICG and bi-directional converters is mathematically modeled, simulated and optimized considering power supply reliability, Levelized Energy Cost (LEC) and Renewable Energy Capacity (REC). Obtained Pareto fronts were analyzed and simple multi-criterion decision making technique is used to come up with the final system design.
item: Conference-Abstract
Multi objective optimization of lifecycle cost, unmet load, and renewable energy capacity an expansion of existing standalone internal combustion generator (ICG) systems
Perera, ATD; Attalage, RA; Perera, KKCK
Expanding existing Internal Combustion Generator (ICG) systems by incorporating renewable energy sources is getting popular due to its potential to reduce the emission of Green House Gases (GHG) and fuel consumption. Designing such Hybrid Energy System (HES)s become challenging due to the seasonal variation of renewable energy sources resulting either poor reliability of power supply or higher expenditure, which makes it essential to optimize Levelized Energy Cost (LEC), Unmet Load Fraction and Renewable energy capacity at the early design stages. This study evaluates the results obtained through such optimization based on evolutionary algorithm. In order to accomplish this, mathematical modeling and simulation of a stand-alone HES was carried out along with the optimization. Obtained results shows that both wind and Solar PV (SPV) capacity is having a significant impact on LEC, unmet load fraction and fuel consumption
item: Conference-Abstract
Optimal design and control of multiple boiler systems using fuzzy-evolutionary hybrid algorithm
Perera, ATD; Kumarage, P; Perera, KKCK
Optimal load management of energy system is been widely discussed due to the higher depletion rate of fossil fuel resources and ever increasing energy demands. In such circumstances, optimal design and control of boiler systems play a major role. New algorithm based on fuzzy-evolutionary hybrid techniques is being introduced in this study to carry out this work. Detailed energy flow and life cycle cost model was introduced in order to support the optimization. Finally, optimization algorithm was tested for two different load curves and obtained results were discussed.
item: Conference-Abstract
Optimal design of a grid connected hybrid electrical energy system using evolutionary computation
(2014-06-19) Perera, ATD; Attalage, RA; Perera, KKCK
Hybrid Energy Systems (HESs) are becoming attractive solution for both grid connected and stand-alone applications. A number of factors need to be considered in designing HESs where multi-objective optimization becomes useful. Multi-objective optimization is used in this study to arrive at optimum systems designs for a grid connected HES considering Levelized Energy Cost (LEC) and Level of Grid Integration (LGI) as objective functions. Sensitivity analysis was conducted subsequently, considering factors like equipment cost and cost of grid electricity.
item: Article-Full-text
Sensitivity of internal combustion generator capacity in standalone hybrid energy systems
(Elsevier, 2012) Perera, ATD; Wickremasinghe, DMIJ; Mahindarathna, DVS; Attalage, RA; Perera, KKCK; Bartholameuz, EM
With higher depletion rates of fossil fuels and the ever growing environmental concerns on Green House Gas (GHG) emissions it has become important to investigate the impact of Internal Combustion Generator (ICG) capacity in Hybrid Energy System (HES)s for standalone applications. In order to accomplish this objective HES modeling, simulation, and optimization was done for three different system configurations based on the renewable energy source. Both mono and multi objective optimization was carried out using Evolutionary Algorithm considering Levelized Energy Cost (LEC) and unmet load fraction as objective functions. Results clearly depicts that seasonable variation of renewable energy sources having a strong impact on system component selection under higher power supply reliability which gradually reduce with the increase of ICG capacity.
item: Conference-Full-text
A techno-economic analysis for an integrated solar PV/T system with thermal and electrical storage – case study
(2015-08-03) Athukorala, AUCD; Jayasuriya, WJA; Ragulageethan, S; Sirimanna, MPG; Attalage, RA; Perera, ATD
A hybrid photovoltaic/thermal (PV/T) system is having the capability to convert solar energy to both electricity and thermal energy simultaneously and these systems can use to accomplish the energy demand of buildings. Performance analysis of such systems becomes essential to design PV/T systems matching with the operating conditions. It is essential to extend the energy flow analysis used in this regard considering economic limitations especially for urban applications. In this study a practical method to accomplish the energy demand of a building from a PV/T system is proposed and evaluated through a thermo-economic model. The performance of the PV/T collector is analyzed under different operating conditions in Sri Lanka. The responses of energy storage and local grid according to demand variations of the building are evaluated considering the economic aspects. Life cycle cost of the PV/T system is computed to assess the economic viability of harnessing energy from solar energy. Furthermore, the capability of deploying PVT technique and the potential to harvest solar energy in Sri Lanka is evaluated through conducting case studies for different locations.
item: Conference-Abstract
A techno-economic analysis for an integrated solar PV/T system with thermal and electrical storage — Case study
Athukorala, AUCD; Jayasuriya, WJA; Ragulageethan, S; Sirimanna, MPG; Attalage, RA; Perera, ATD
A hybrid photovoltaic/thermal (PV/T) system is having the capability to convert solar energy to both electricity and thermal energy simultaneously and these systems can use to accomplish the energy demand of buildings. Performance analysis of such systems becomes essential to design PV/T systems matching with the operating conditions. It is essential to extend the energy flow analysis used in this regard considering economic limitations especially for urban applications. In this study a practical method to accomplish the energy demand of a building from a PV/T system is proposed and evaluated through a thermo-economic model. The performance of the PV/T collector is analyzed under different operating conditions in Sri Lanka. The responses of energy storage and local grid according to demand variations of the building are evaluated considering the economic aspects. Life cycle cost of the PV/T system is computed to assess the economic viability of harnessing energy from solar energy. Furthermore, the capability of deploying PVT technique and the potential to harvest solar energy in Sri Lanka is evaluated through conducting case studies for different locations.
item: Conference-Abstract
A Techno-economic analysis for an integrated solar PV/T system with thermal and electrical storage – case studyt
Athukorala, AUCD; Jayasuriya, WJA; Ragulageethan, S; Sirimanna, MPG; Attalage, RA; Perera, ATD
A hybrid photovoltaic/thermal (PV/T) system is having the capability to convert solar energy to both electricity and thermal energy simultaneously and these systems can use to accomplish the energy demand of buildings. Performance analysis of such systems becomes essential to design PV/T systems matching with the operating conditions. It is essential to extend the energy flow analysis used in this regard considering economic limitations especially for urban applications. In this study a practical method to accomplish the energy demand of a building from a PV/T system is proposed and evaluated through a thermo-economic model. The performance of the PV/T collector is analyzed under different operating conditions in Sri Lanka. The responses of energy storage and local grid according to demand variations of the building are evaluated considering the economic aspects. Life cycle cost of the PV/T system is computed to assess the economic viability of harnessing energy from solar energy. Furthermore, the capability of deploying PVT technique and the potential to harvest solar energy in Sri Lanka is evaluated through conducting case studies for different locations.