School Of Renewable Energy Technology Research Articles

Fuzzy Control Algorithm for Battery Storage and Demand Side Power Management for Economic Operation of the Smart Grid System at Naresuan University, Thailand

This paper presents a fuzzy logic-based algorithm developed for battery storage power management (BSPM) and demand side power management (DSPM) for the School of Renewable Energy Technology (SERT)-Smart Grid (SSG) at Naresuan University in Phitsanulok, Thailand. This algorithm enables lower cost operation of the SSG by utilizing the time of use electricity-pricing concept and thus is called the Fuzzy Low-cost Operation (FLO) algorithm. After applying the FLO algorithm to the SSG, the BSPM can strategically handle fluctuating PV production by intelligently alternating between absorbing power during high solar irradiation periods and discharging power to the load during peak consumption times. The FLO algorithm also empowers the SSG’s DSPM to decrease the peak load by using SERT’s building energy management system to disconnect noncritical load as desired, for example lighting, air conditioners, and dummy heater load (used for research testing purposes). Research results show that the FLO algorithm successfully decreased SERT’s annual electricity bill by 17.58%, equivalent to a grand total of $9148 in annual savings. Of 17.58% in savings, 5.78% came from modifications to the BSPM and 11.81% came from modifications to the DSPM. The average monthly savings correspond to $762 ($250 from BSPM and $512 from the DSPM), significant savings that without the FLO algorithm would not be available.

Development of solar collector combined with thermoelectric module for solar drying technology

Have been successfully developed the solar drying integrated solar collector and photovoltaic (PV). However, heat waste is transfer from the back side of solar collector to surrounding over operation. A thermoelectric generator (TEG) relies on the "Seebeck effect" to directly convert heat into electricity. TEG is applied to use in specific area such as detector, egg incubator, exhaust car, watch etc. The objective of this research is focused on development a solar drying technology with using solar collector combined with TEG module. The system was constructed and installed at School of Renewable Energy Technology, Naresuan University, Phitsanulok Thailand. Temperature profile the back side of solar collector, power of TEG module, air flow rate of blower were measured and analyzed. As the results, temperature at behind of solar collector was decreased with increasing the produced power of TEG module which corresponded with solar irradiance. Solar collector can be operated and produced hot air temperature about 70-80 °C supported to chamber for drying. TEG can be produced the electricity about 0.0813 V/module. The deference of temperature surface was 1.77 °C and the average temperature of back side 45.4 °C. The ambient temperature was 35.8 °C. In addition, the system can be used blower for controlling air flow rate by using electricity from TEG module. It can be concluded the solar collector can be combined with TEG module for producing the electricity to supply the blower within tunnel drying, including with a guideline for improve the performance of solar drying technology.

Statistical Load Modeling for School of Renewable Energy Technology (SERT) Smart Grid Naresuan University Phitsanalok Thailand

The high level of renewable electricity generation is resulting in transformation of conventional grid into Smart Grid. Due to variable electricity generation the load demand has become critical and challenging issue in electricity market. In this study, the end-use load modeling based on probability distribution has been carried out in School of Renewable Energy Technology (SERT) Naresuan University Phitsanalok Thailand. For the data of electricity usage in office at SERT the most suitable model i.e., Weibull distribution have been emulated. The shape and scale parameters have been estimated along with Kolmogorov-Smirnov goodness of fit test.

Evaluation of Solar Fraction on a Solar Driven Dual Parallel Connected Ejector Cooling System

This present study reports results of performance evaluation of a solar-driven dual parallel-connected ejector (DPE) cooling system using the concept of solar fraction (SF). The experiments were conducted in July and August, 2015 from 09:00 to 16:00 hours at School of Renewable Energy Technology (SERT), Naresuan University, Thailand, with a solar collector area of 2.4 m2, auxiliary heater of 3 kW, operating at boiler pressure of 2 bar and using water as working fluid. Temperature was measured for inlet and outlet of solar collector. The results showed that the solar collector supplied about 24% of energy required to operate the system. The solar collector performance was 11% and the monthly average SF was 23.9% for July and 23.5% for August.

The Study of Decrement in Insulation Resistance of PV String and its Effects on PV System Degradation

This paper presents the investigated variations in insulation resistances of amorphous silicon (a-Si), multi crystalline silicon (MC-Si) and hybrid solar cell (HIT). The insulation resistance of PV string of each system was measured and used to represent leakage current in photovoltaic system and the analysis was done in accordance with IEC 61215 Standard. The 10.152 kW multi-PV cell technologies grid connected system supports the energy demand of the 10 kW Building at School of Renewable Energy Technology (SERT), Naresuan University since July 2005 till date. In general the system was found effectively working under hot and humid climatic conditions of Thailand for a long duration. However the decrement in insulation resistance (MΩ) of a-Si string, MC-Si string and HIT string have affected electrical parameter of each system. The decrements in fill factor (F.F) over the 10 years period (July 13, 2005 – January 25, 2015) of a-Si, MC-Si and HIT were-27.4%, -21.9% and-6.2% respectively.

The Effect of Average Photon Energy and Module Temperature on Performance of Photovoltaic Module under Thailand's Climate Condition

This article present the effect of average photon energy and module temperature on performance of amorphous silicon (a-Si), polycrystalline (p-Si) and hetero-junction intrinsic thin layer (HIT) photovoltaic (PV) modules under Thailand climatic condition which located at the equator zone. The outdoor solar irradiance distribution measurements on the PV array installed at Energy Park, School of Renewable Energy Technology (SERT), Naresuan University, Thailand revealed that the field output factor of the poly-Si and HIT PV modules depended almost only on a module temperature, while that of the a-Si ones mainly depended on APE. The behaviors were reasonable considering from the operating mechanisms of the PV modules. These results demonstrate that APE is a reasonable and useful index to describe the spectral irradiance distribution for evaluating the performance of PV modules.

Simulation for the Management of Power Exchange and Payment between Renewable Energy and Electric Utility Network

This paper presents a model simulation of the electric power exchange and the electricity bill for four case-study buildings where three buildings have photovoltaic systems. The data for power demand and power supply which is produce from the photovoltaic system in each building were collected at the School of Renewable Energy Technology (SERT), Naresuan University, Thailand. The data for the power demand were then converted to the load profile curves and calculated for the photovoltaic performance from the solar radiation data. Building load balancing algorithm was developed from the simulation model with the data from load profiles and photovoltaic performances. The results from the overall load balancing algorithm were reported as the net metering and the power status of each building. The load balancing algorithm focused on the initial exchange of power between each building. Then, if higher power demand is required, the power would be from the external source such as the existing utility grid or another building. The result of simulation for four case-study building indicated that under the load balancing algorithm criteria, the buildings could sell 44% (261.99 baht/day) of its power from the photovoltaic system to another building while purchasing 56% (337.92 baht/day) power from the existing utility grid. In the future, this power exchange algorithm could be applied for energy saving and energy efficiency improvement to the homes, buildings, and offices.

Performance of Steam Production by Biomass Combustor for Agro-industry

This research paper aims to particularly raise the issue how optimization of steam production produced by a biomass combustor is regarded to agricultural industry, for the produced steam will consequently be applied to sterilization or even drying process. The most optimal level of steam production will be explored as to how to optimally achieve flow rate of air, rate of fuel input, the rate of steam production, and steam production in compliance with the given 100 kg/h capacity and the required temperature of between 90-100°C . Biomass steam production incorporates 3 major parts: 1) biomass combustor, 2) heat exchanger system (coiled tube), and 3) control system, administered the whole process, located at the School of Renewable Energy Technology, Naresuan University, Phitsanulok. A combustion system was tested through the implementation of eucalyptus charcoal as the main source of energy. The research finding revealed that the combustion system could generate steam at 100 kg/h which consumed eucalyptus charcoal at the temperature value of Heating value of fuel (HHV) was 30.0 MJ/kg. This was conducted within the biomass combustor, engaged with a coil tube, at the flow rate of 172.8 kg/h, the value of feed rate of fuel at 15 kg/h, and a steam production rate at 100 kg/h respectively. The efficiency of steam production was at 58.25%. When the taken result was brought to compare with a mathematical model with experiment result of steam production, it was found out that the error value was 0.9997 which could usefully be used to predict steam production in the system. With reference to the economical benefit, when compared to steam production produced by LPG fuel at 100 kg/h production rate, it was obvious that steam production generated by biomass could redeem the spent investing cost with less than one year. This would greatly be interesting and applicable to industry particularly agriculture that steam production by biomass combustor with helical coiled boiler technique will be used to energy backup for drying system. However steam production will be supported drying system after utilization in another thermal process the temperature not more than 100°C within industrial or industrial house hold.

The Effect of Photon Flux Density and Module Temperature on Power Output of Photovoltaic Array

This article presents the effects of photon flux density and module temperature on power output of amorphous silicon (a-Si), polycrystalline (p-Si) and hetero-junction intrinsic thin layer (HIT) photovoltaic (PV) modules under Thailand climatic condition which located at the equator zone. The outdoor solar irradiance distribution measurements on the PV array installed at Energy Park, School of Renewable Energy Technology (SERT), Naresuan University, Thailand revealed that the solar irradiance is directly proportional with photon flux density which the wavelength is influence of photon flux density. The increasing of power output under real working of a-Si and p-Si depends on both photon flux density and module temperature. But the increasing of power output of HIT mainly depends on both photon flux density.

Performance Evaluation of 10 kWp Photovoltaic Power Generator under Hot Climatic Condition

This article presents the performance of 10 kWp photovoltaic power generator (PVPG) during 6 years under hot climatic condition. The PVPG is installed in 2005 at Energy Park, School of Renewable Energy Technology (SERT), Naresuan University, Phitsanulok, Thailand. This system consists of 3 PV technologies; Amorphous Silicon (a-Si), Poly Crystalline Silicon (p-Si), and Hybrid Silicon (HIT) with monitoring system to meet the guideline of IEC 61724. All of the important parameters are recorded from June 2005 to December 2010, which were used in evaluation processes. The results of this research found that the highest average array yield (YA) of a-Si, p-Si and HIT are 4.86h/d, 4.36h/d and 4.60h/d, respectively at reference yield 5.27h/d. The average array efficiency ηA) of a-Si, p-Si and HIT are 5.89%, 10.59% and 13.41%, respectively. a-Si has highest average annual array performance ratio about 0.92%, HIT 0.87% and the lowest is p-Si 0.83%.

PV Generator Performance Evaluation and Load Analysis of the PV Microgrid System in Thailand

Normally, the main generators of microgrid system use controllable energy resources such as fossil fuel, biomass, biogas, hydro, etc for uncomplicated control. However, it is very challenging to control the microgrid system that uses uncontrollable energy resources such as solar and wind for main generators of microgrid system because they have many advantages. From this point, the PV microgrid system is constructed and operated at School of Renewable Energy Technology (SERT), Naresuan University for research and development of the microgrid system that is supplying 50% of total electricity demand by PV main generator. By measuring the important parameters such as solar irradiance, PV array voltage, PV array current, and AC electrical power, these data were collected for a year from November 2008 to October 2009 to use in evaluation processes. The PV generator evaluation result is revealed that the average reference yield (Yr), array yield (YA), and final yield (Yf) are 5.21, 4.32, and 3.84 kWh/kWp day respectively. The average total loss of the PV generator is 26.27% that comes from summing up the average capturelosses (LC) 17.21% and average system losses (LS) 9.06%. The average overall PV plant efficiency (ηtot) is 10.41%, and the average performance ratio (PR) is 73.45%. For load analysis of the microgrid, the total load is 231673 kWh/year or 635 kWh/day that the main loads of the microgrid are the real load and the battery storage loss. For the real load, it varies from 9803 to 22506 kWh/month and the average real load is 15434 kWh/month. However, the battery storage loss is really constant at 3888 kWh/month. When consider the load profile, it shows that the peak load period is 8 A.M. to 7 P.M. and the off peak load periods are 0 A.M. to 8 A.M. and 7 P.M. to 0 A.M. Moreover, the load in peak load period of working day is higher than day off but the load in off peak load period is not different. When compare the load profile with PV generator production, the load is 100% supplied by PV generator during 8 A.M. to 4 P.M. in working day and 8 A.M. to 5 P.M. in day off. Moreover, PV generator generates the surplus energy 169 kWh/day in working day and 232 kWh/day in these periods.

Investigation on Temperature Coefficients of Three Types Photovoltaic Module Technologies under Thailand Operating Condition

This article describes a methodology to find the temperature dependence coefficients of amorphous silicon, poly crystalline and Heterojunction Intrinsic thin layer photovoltaic (PV) module. There are measured under Thailand Operating Condition. This study present three technologies of photovoltaic modules using 3.67 kWp (68 modules) of Amorphous Silicon Solar Cell (a-Si),3.60 kWp (45 modules) of Poly Crystalline Silicon Solar Cell (p-Si) and 2.88 kWp (16 modules) of Heterojunction Intrinsic Thin Layer (HIT). There were installed at Energy Park, School of Renewable Energy Technology, Naresuan University (north latitude 16o47’, east longitude 100 o16’). The 10kW PV power station data have been recorded since year 2008 January to 2009 December. It is analyzed by linear regression technique. In addition, an average solar irradiance value in 2008 was 660W/m2 and 640W/m2 in the year 2009. Upon analysis, the study will show the Temperature coefficient of current, voltage, power and efficiency on array temperature obtained from liner regression. These findings of field test investigation found that the temperature coefficient value of PV array different from the factory value and the temperature coefficients in the year 2009 is higher than the year 2008. These results have an impact on systems design and sizing in similar climate regions. Thus, recommended that design and sizing of PV system in Tropical climate regions of the world take due address to these results.

Impact of spectral irradiance distribution on the outdoor performance of photovoltaic system under Thai climatic conditions

This paper presents the effects of spectral irradiance distribution on the performance of polycrystalline (p-Si) and amorphous silicon (a-Si) photovoltaic (PV) modules under Thai climatic conditions. The annual outdoor solar spectrum measurements bouncing on the PV modules installed at Energy Park, School of Renewable Energy Technology (SERT), Naresuan University, Thailand revealed that the average photon energy (APE) of total incident solar irradiance was 50% higher than that at standard test conditions. The results show that the power output of a-Si PV module mainly depends on spectrum distribution. In contrast, the power output of p-Si is not sensitive to spectrum distribution. Because of the different spectrum response of p-Si and a-Si PV modules, the actual irradiance spectrum data of each location under real working conditions are necessary for optimizing PV design.

Evaluation of PV Generator Performance and Energy Supplied Fraction of the 120 kWp PV Microgrid System in Thailand

Abstract Normally, the main generators of microgrid system use controllable energy resources such as fossil fuel, biomass, biogas, hydro, etc for uncomplicated control. However, it is very challenging to control the microgrid system that uses uncontrollable energy resources such as solar and wind for main generators of microgrid system because they have many advantages. From this point, the PV microgrid system is constructed and operated at School of Renewable Energy Technology (SERT), Naresuan University for research and development of the microgrid system that is supplying 50% of total electricity demand by PV main generator. By measuring the important parameters such as solar irradiance, PV array voltage, PV array current, and AC electrical power, these data were collected for a year from November 2008 to October 2009 to use in evaluation processes. The PV generator evaluation result is revealed that the average reference yield (Yr), array yield (YA), and final yield (Yf) are 5.21, 4.32, and 3.84 kWh/kWp day respectively. The average total loss of the PV generator is 26.27% that comes from summing up the average capture losses (LC) 17.21% and average system losses (LS) 9.06%. The average overall PV plant efficiency (ηtot) is 10.41%, and the average performance ratio (PR) is 73.45%. While considering the system efficiency of the PV generator at various solar irradiance, we found that it has the lowest efficiency when the solar irradiance is in the range 0 - 0.10 kW/m2, its efficiency increases with the increasing in the solar irradiance from 0.10 to 0.35 kW/m2, the efficiency becomes highest when the solar irradiance in the range of 0.35 to 0.65 kW/m2, and its efficiency decreases slowly when the solar irradiance is in the range of 0.65 to 1.30 kW/m2. For energy supplied fraction of the microgrid, it can achieve the PV generator producing target by PV generator and external grid supplying 73% and 27% of the total load of the microgrid.

Optimization and payback period of steam production by biomass combustor for Agro-industry

Abstract This research paper aims to particularly raise the issue how optimization of steam production produced by a biomass combustor is regarded to agricultural industry, for the produced steam will consequently be applied to sterilization or even drying process. The most optimal level of steam production will be explored as to how to optimally achieve flow rate of air, Rate of fuel input and the rate of steam production, and steam production in compliance with the given 100 kg/h capacity and the required temperature of between 90-100 OC Celsius. Biomassed steam production incorporates 3 major parts: 1) biomass combustor, 2) heat exchanger system (coiled tube), and 3) control system, administered the whole process, located at the School of Renewable Energy Technology, Naresuan University, Phitsanulok. A combustion system was tested through the implementation of eucalyptus charcoal as the main source of energy. The research finding revealed that the combustion system could generate steam at 100 kg/h which consumed eucalyptus charcoal at the temperature value of Heating value of fuel (HHV) was 30.0 MJ/kg. This was conducted within the biomass combustor, engaged with a coil tube, at the flow rate of 172.8 kg/h, the value of feed rate of fuel at 15 kg/h, and a steam production rate at 100 kg/h respectively. The efficiency of steam production was at 58.25%. When the taken result was brought to compare with a mathematical model of steam production, it was found out that the error value was 0.9997 which could usefully be used to predict steam production in the system. With reference to the economical benefit, when compared to steam production produced by LPG fuel at 100 kg/h production rate, it was obvious that steam production generated by biomass could redeem the spent investing cost with less than one year. This would greatly be interesting and applicable to industry particularly agriculture.

Experience with fully operational solar-driven 10-ton LiBr/H 2O single-effect absorption cooling system in Thailand

A solar-driven 10-ton LiBr/H 2O single-effect absorption cooling system has been designed and installed at the School of Renewable Energy Technology (SERT), Phitsanulok, Thailand. Construction took place in 2005, after which this system became fully operational and has been supplying cooling for our main testing building's air-conditioning. Data on the system's operation were collected during 2006 and analyzed to find the extent to which solar energy replaced conventional energy sources. Here, we present these data and show that the 72 m 2 evacuated tube solar collector delivered a yearly average solar fraction of 81%, while the remaining 19% of thermal energy required by the chiller was supplied by a LPG-fired backup heating unit. We also show that the economics of this cooling system are dominated by the initial cost of the solar collector array and the absorption chiller, which are significantly higher than that of a similar-size conventional VCC system.

Additions to List of Technical Films

This research paper aims to particularly raise the issue how optimization of steam production produced by a biomass combustor is regarded to agricultural industry, for the produced steam will consequently be applied to sterilization or even drying process. The most optimal level of steam production will be explored as to how to optimally achieve flow rate of air, rate of fuel input, the rate of steam production, and steam production in compliance with the given 100 kg/h capacity and the required temperature of between 90-100°C . Biomass steam production incorporates 3 major parts: 1) biomass combustor, 2) heat exchanger system (coiled tube), and 3) control system, administered the whole process, located at the School of Renewable Energy Technology, Naresuan University, Phitsanulok. A combustion system was tested through the implementation of eucalyptus charcoal as the main source of energy. The research finding revealed that the combustion system could generate steam at 100 kg/h which consumed eucalyptus charcoal at the temperature value of Heating value of fuel (HHV) was 30.0 MJ/kg. This was conducted within the biomass combustor, engaged with a coil tube, at the flow rate of 172.8 kg/h, the value of feed rate of fuel at 15 kg/h, and a steam production rate at 100 kg/h respectively. The efficiency of steam production was at 58.25%. When the taken result was brought to compare with a mathematical model with experiment result of steam production, it was found out that the error value was 0.9997 which could usefully be used to predict steam production in the system. With reference to the economical benefit, when compared to steam production produced by LPG fuel at 100 kg/h production rate, it was obvious that steam production generated by biomass could redeem the spent investing cost with less than one year. This would greatly be interesting and applicable to industry particularly agriculture that steam production by biomass combustor with helical coiled boiler technique will be used to energy backup for drying system. However steam production will be supported drying system after utilization in another thermal process the temperature not more than 100°C within industrial or industrial house hold.