Malaysian Solar Iradiation 2010

An Evaluation Data of Solar Irradiation and DryBulb Temperature at Subang under Malaysian

ClimateM.Z. Hussin#1, M.H.A. Hamid#2, Z.M. Zain#3, R.A. Rahman*4

# Faculty of Electrical Engineering, Universiti Teknologi Mara

40450 Shah Alam Selangor Darul [email protected]

[email protected]* Photovoltaic Monitoring Centre (PVMC), Universiti Teknologi Mara

40450 Shah Alam Selangor Darul Ehsan

Abstracts— Solar irradiation and the temperature played a major role in the PV designing system. This factor differs with the latitude, geographic and time of day due to the various sun positions.This paper presents an average of solar irradiation over 10 years data for the Subang area with respect to the complete set data of daily global solar radiation that monitored by the Malaysian Meteorological Department (MMD) from year 1993 to 2002.In this study, the data were analysed to understand the pattern of hourly solar irradiance and also to recommend the appropriate value of daily solar irradiation for the designing of PV system in Malaysia region especially for Subang and Klang Valley. The highest sum of 24 hours average solar irradiation per year was 4.72 kWh m-2 in 1998 as well as temperature 28.5 °C and the annually average solar irradiations for Subang were collected from 3.91 kWh m-2 to 4.30 kWh m-2 during 10 years period. Also, the recommended daily solar irradiation in Malaysian climate is 4.39 kWh m-2, 133.0 kWh m-2 for monthlyand the standard value for annual is 1596.5 kWh m-2 .The standard deviation for daily solar irradiation is 0.29.

Keywords— Solar Irradiation, Dry Bulk, Temperature, Photovoltaic.

I. INTRODUCTION

Malaysia is one of the country that are still use fossil fuels as main source of energy today but also aware of the consequences of relying on this energy source for our natural environment. The climate of Malaysia is tropical and humid. So, it’s suitable to use safer alternative energy sources such as solar, wind, water and so on. Since there is more concern on energy conservation and environmental protection, the global priority has been increasingly addressed on the solar energy. Solar energy as a clean energy source and safer alternative renewable energy is abundant in Malaysia. The weather condition in Malaysia is very suitable for photovoltaic implementation. This is because the weather condition is almost predictable and the availability of sunlight for more than 10 h daily. As it is possible to have about 6 h of direct sunlight with irradiation of between 800 W/m2 and 1000 W/m2, it is already very good to consider for the usage of photovoltaic [1].This country experiences relatively uniform

temperature throughout the year, with the mean temperature in the lowlands ranging between 26 °C and 28°C. It has a tropical climate with annual southwest (from April to October) and northeast (from October to February) monsoons[2]. A photovoltaic (PV) system should be installed to maximise the solar contribution to a particular load. Optimum PV inclination and orientation depends on local climate, load consumption temporal profile and latitude. Generally, a surface with tilt angle equal to the latitude of a location receives maximum insolation [3].The differences due to weather conditions in are more important. This paper discussed about the significant of the understanding solar irradiance pattern and the long term monitoring data which highly contributed to the optimum design of PV system in Malaysian region.

II. SOLAR IRRADIATION IN SUBANG

Subang Jaya is geographically located at latitude (3.0825 degrees) 3° 07’ North of the Equator and longitude (101.5879 degrees) 101° 35' East of the Prime Meridian on the Map of Kuala Lumpur and the elevation of the city is at 17.0 meters height above mean daily sea level pressure (M.S.L). The data of solar radiation and the temperature of Subang Jaya is the main station and managed by the Malaysian Meteorological Service's personnel. Hourly solar radiation is obtained from the readings of the solarimeter and the hourly air temperature is measured with dry bulb thermometer [4].

2010 IEEE Control and System Graduate Research Colloquium

978-1-4244-7240-6/10/$26.00 ©2010 IEEE 55

Fig.1 Malaysian Meteorological station

III. MATERIALS AND METHODS

A. Data Observations

In the present study, the dataset of monthly average daily global radiation on a horizontal surface from Malaysian Meteorological Department (MMD) weather stations in Subang between 1993 and 2002 was used to estimate hourlyand annually values. The meteorological data was taken ininterval for every 1 hour. From the raw data, the maximum and minimum hourly values per year were calculated .From hourly data and daily data distribution were made for the solar radiation and temperature data to analyse the average solar radiation data for Subang were produced by using the daily global solar radiation recorded at Subang station. The trend and pattern analysis of both temperature and solar radiation has been carried out by analyzing both the temperature and solar radiation data for Malaysia over the last one decade (1993-2002).Generation of average solar radiation per year is the real data that were recorded by Subang MMD and had chosen solar data from 1993 until 2002.However, the observation average solar radiation and temperature was developed using available solar data in MMD weather station located in Subang.

IV. RESULT AND DISCUSSION

Generally, the data was taken at Subang. It can be seen that the peak distribution of average hourly solar irradiance as well as temperatures are higher from 7am until 1pm and lower from 2pm until 7pm (morning to late evening). The hourly average of solar irradiance for Subang during 1993 to 2002 periods was compared in table 1. Clearly, the highest hourly average solar radiance among 10 years is 1998 with 0.69 kWm-2 day-1 was recorded and the lowest is 0.02 kW m-2 day-1 in the same year. Within 10 year period’s data was taken, it can be founded that the average values are approximately around 4.39 kWh m-2 yr-1 throughout the periods.

In table 2, it can be said that the minimum value of dry bulb temperature was noted usually at 6pm during the dawn time. Instead, the maximum values of dry bulb temperature fall at period between 1pm to 2pm in a day.

TABLE 1AVERAGE HOURLY VALUES OF SOLAR IRRADIANCE, KW M-2

YEAR-1 OBTAIN 10 YEARS DATA FOR SUBANG

Hour 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.03 0.02 0.03 0.03 0.02 0.02 0.02 0.03 0.03 0.02

8 0.15 0.15 0.18 0.17 0.13 0.14 0.14 0.18 0.17 0.16

9 0.32 0.31 0.37 0.36 0.32 0.32 0.32 0.37 0.35 0.35

10 0.47 0.46 0.54 0.52 0.48 0.49 0.49 0.54 0.51 0.52

11 0.56 0.56 0.65 0.63 0.61 0.63 0.61 0.64 0.62 0.63

12 0.60 0.58 0.68 0.68 0.66 0.69 0.66 0.67 0.66 0.67

13 0.57 0.55 0.65 0.65 0.65 0.67 0.65 0.64 0.63 0.62

14 0.48 0.47 0.56 0.57 0.56 0.61 0.56 0.55 0.55 0.52

15 0.36 0.37 0.44 0.44 0.45 0.49 0.44 0.43 0.42 0.40

16 0.23 0.24 0.29 0.30 0.31 0.36 0.31 0.29 0.30 0.26

17 0.12 0.12 0.16 0.17 0.17 0.21 0.19 0.16 0.16 0.13

18 0.03 0.03 0.04 0.05 0.07 0.08 0.08 0.05 0.04 0.03

19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

21 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Yearly average daily solar

irradiation (kWh/m²/day) 3.91 3.86 4.59 4.57 4.44 4.72 4.46 4.54 4.46 4.30

Max. daily solar

irradiance (kW/m²/day) 0.60 0.58 0.68 0.68 0.66 0.69 0.66 0.67 0.66 0.67

Min. daily solar

irradiance (kW/m²/day) 0.03 0.02 0.03 0.03 0.02 0.02 0.02 0.03 0.03 0.02

TABLE 2AVERAGE HOURLY DRY TEMPERATURE, ° C OBTAINED DURING

10 YEARS PERIOD FOR SUBANG

Hour 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

1 25.0 25.2 25.5 25.5 25.6 26.4 25.5 25.6 25.8 25.9

2 24.8 24.9 25.3 25.2 25.3 26.1 25.2 25.4 25.6 25.7

3 24.6 24.7 25.1 25.0 25.1 25.9 25.0 25.2 25.3 25.4

4 24.4 24.6 24.9 24.8 25.0 25.7 24.8 25.0 25.1 25.2

5 24.2 24.4 24.7 24.7 24.8 25.5 24.6 24.8 25.0 25.1

6 24.1 24.3 24.6 24.6 24.8 25.4 24.5 24.7 24.8 24.9

7 24.3 24.5 24.8 24.8 25.0 25.6 24.6 24.8 25.0 25.1

8 25.7 25.8 26.1 26.2 26.4 27.0 26.1 26.2 26.3 26.7

9 27.7 27.7 28.0 28.0 28.4 28.8 27.8 28.0 28.0 28.8

10 29.3 29.3 29.5 29.5 29.9 30.2 29.4 29.6 29.5 30.3

11 30.4 30.4 30.5 30.5 31.0 31.3 30.4 30.7 30.6 31.4

12 31.0 31.1 31.2 31.2 31.7 32.0 31.1 31.4 31.4 32.1

13 31.3 31.5 31.5 31.5 32.0 32.5 31.4 31.7 31.7 32.5

14 31.3 31.3 31.5 31.6 31.9 32.5 31.2 31.5 31.8 32.3

15 30.8 30.9 30.9 31.0 31.4 32.1 30.6 31.1 31.3 31.6

16 30.0 30.1 30.1 30.2 30.4 31.4 30.0 30.4 30.6 30.7

17 29.1 29.1 29.3 29.4 29.4 30.4 29.3 29.5 29.8 29.9

18 28.2 28.3 28.4 28.5 28.4 29.5 28.5 28.6 28.9 29.0

19 27.3 27.4 27.6 27.7 27.7 28.5 27.6 27.7 28.1 28.1

20 26.7 26.9 27.1 27.2 27.2 28.0 27.0 27.2 27.5 27.6

21 26.3 26.5 26.7 26.8 26.9 27.6 26.6 26.8 27.1 27.1

22 25.9 26.1 26.4 26.4 26.6 27.2 26.3 26.4 26.7 26.8

23 25.6 25.8 26.1 26.1 26.3 26.9 26.0 26.1 26.4 26.5

24 25.3 25.5 25.8 25.8 25.9 26.7 25.7 25.9 26.1 26.2

Yearly average daily

dry bulb temp. °C 27.2 27.3 27.6 27.6 27.8 28.5 27.5 27.7 27.8 28.1

Max. average daily

dry bulb temp. ° C 31.3 31.5 31.5 31.6 32.0 32.5 31.4 31.7 31.8 32.5

Min. average daily

dry bulb temp. ° C 24.1 24.3 24.6 24.6 24.8 25.4 24.5 24.7 24.8 24.9

Fig. 2 below describes the pattern of the average hourly solar irradiance for the 10 years period. Every hours indicates that the increment of solar irradiance until 12pm and then slightly drop after 1pm until 7pm. At 12pm, the solar irradiance reaches the maximum values.


56

Fig. 2 The pattern of hourly average solar irradiance during 10 years

Fig. 3 The pattern of hourly average dry bulk temperature during 10 years

Fig. 3 above shows that the pattern temperature distribution during 7am to 1pm, the rate of dry temperature for 24 hours reach the higher point (exceed 25 °C) and then smoothly fall around 2 pm until the midnight, which result in the observed peak. Otherwise, the minimum hourly average temperature was recorded at 24.1 °C (1993, 6am). It can be seen that therange of temperature between 25 °C and 30 °C is occurred due the hot climate and high humidity condition.

Fig. 4 The yearly average daily solar irradiation and the average dry bulb temperature per year from 1993 to 2002(10 years)

Fig. 4 shows the total solar irradiation and the average dry temperature per year from 1993 to 2002. It can be seen that the temperature graph increased gradually throughout the 10 years period. In year 1998, 28.5°C was recorded as the maximum average temperature per year. This issue occurred due to the effects of the increasing global warmth caused by the El Niño phenomenon. The large-scale climate phenomenon El Niño can contribute to average warmth in global temperature (Fig. 5 below), as was the case with the extremely strong 1997/1998 episode [6]. Instead of the changing in temperature, the Klang Valley area also suffered in water shortage during that year. There is an overall increasing trend of the dry temperature for Subang’s area and there’s no indication of a cycle period. Hence, it can be said as upward trend. The trend lines of the total amount solar radiation per year is quite fluctuate rather than the average temperature graph. It can be shown that among 10 years the highest receives solar irradiation in year 1998. The highest amount of total average solar irradiation receive per year was noted in year 1998 with 4.72 kWh m-². The minimum is 3.86kWh m-2 in year 1994. In previous studies by Ayu Wazira Azhari (2006), the average solar radiations receive a year in Malaysia is about 4.96 kWh m-2. Other studies by Kamaruzzaman and Mohd Yusof (1992) indicate almost the same results but there is a slight increase in the minimum value from 3.375 kWh m-2 in 1992 to 4.21 kWh m-2 in 2006 [7]. As expected, based on statement above, the yearly average daily solar radiation shows that there is a significant relation solar radiation intensity between the result during 10 years is quite similar with the previous studies have been made.


57

Fig. 5 Global annual temperature anomaly percentiles for 2005 based on a gamma distribution for the 1961-1990 base periods

Fig. 6 Monthly solar irradiation in year 1993








58




Fig. 16 Average Solar Contour Image for Subang (1993-1997)

Fig. 17 Average Solar Contour Image for Subang (1998-2002)

TABLE 5THE OPTIMUM OF AVERAGE SOLAR IRRADIATION AND

STANDARD DEVIATION FOR SUBANG AND KLANG VALLEY AREA

Year Daily(kWh) Monthly(kWh) Annually(kWh)

1993 3.91 118.7 1424.7

1994 3.86 115.4 1384.6

1995 4.59 139.6 1674.7

1996 4.57 138.2 1658.0

1997 4.44 135.0 1620.6

1998 4.72 143.4 1721.2

1999 4.46 135.5 1626.1

2000 4.54 138.1 1657.4

2001 4.46 135.7 1628.2

2002 4.30 130.8 1569.9

Average 4.39 133.0 1596.5

Max. 4.72 143.4 1721.2

Min. 3.86 115.4 1384.6

Std Dev 0.29 9.1 108.9

Fig. 16 and 17 describes the average solar irradiation in Subang by the contour plot. The intensity of solar irradiation is the highest in February, March and April at around 12 noon. The area of high intensity solar irradiation for 1998 to 2002 is wider than area high intensity in 1993 to 1997. It indicates that Subang receiving more solar irradiation in 1998 to 2002.To illustrate the differences distribution of solar irradiation, themonthly graph was demonstrated clearly in Fig.6 to 15 for the different 10 years period.

For Table 5, it represents the optimum average of solar irradiation and the standard deviation during 10 years period. Based on the result, these values can be used as a guideline fordesigning PV system and would be the best recommendation for designer to determine the tilt angle during installation modules was conducted.

Generally, these parameters are covered for horizontal surface only and the value may change slightly when the vertical surface orientation was conducted. The optimumrecommended for average daily solar irradiation, monthly and annually was 4.39 kWh, 133.0 kWh and 1596.5 kWh respectively


59

V. CONCLUSIONS

The climate or weather conditions may fluctuate from year by year. Based on a set of 10 years observation data, the significant result achieved would contribute to the understanding of the behaviour or pattern of average data by year and the highest in year 1998 with 4.72 kWh m-2 yr-1 as well as the dry temperature around 28.5 °C. Obviously, the best optimum value recommended for Subang and Klang Valley region are 4.39 kWh for daily, 133.0 kWh for monthly and 1596.5 kWh for annually. The standard deviation for daily solar irradiation is 0.29 .Also, it will be useful for the designing the PV system at Malaysian region especially for Subang and Klang Valley. High solar irradiation, constantly high temperature and humid characterize the Subang as well as Malaysian climate. From the acquired data on the variation of solar irradiation, a recommendation can be made on the usage of photovoltaic applications in Malaysia and that can serve as guideline for future users who will be interested touse it and continue the research.

ACKNOWLEDGMENT

The researches would like to thank the Malaysian Meteorological Service Department for providing the data for the research.

REFERENCES

[1] Nowshad Amin , Chin Wen Lung , Kamaruzzaman Sopian .”A practical field study of various solar cells on their performance in Malaysia”. Renewable Energy 34 (2009) 1939–1946.

[2] CAI-Asia.2006. ”Country Synthesis Report on Urban Air Quality Management”.

[3] Jayanta Deb Mondol, Yigzaw G. Yohanis, Brian Norton.”The impact of array inclination and orientation on the performance of a grid connected photovoltaic System”. Renewable Energy 32 (2007) 118–140.

[4] Malaysian Meteorological Department, (MMD) http://www.met.gov.my/

[5] Tian Pau Chang.”Study on the Optimal Tilt Angle of Solar Collector According to Different Radiation Types”. International Journal of Applied Science and Enginering 2008.6,2: 151-161.

[6] World Meteorological Organization(WMO-No. 998). “Wmo Statement On The Status Of The Global Climate In 200”5.ISBN: 92-63-10998-2(2006).

[7] Ayu Wazira Azhari , Kamaruzzaman Sopian, Azami Zaharim, Mohamad Al Ghoul. “A New Approach For Predicting Solar Radiation In Tropical Environment Using Satellite Images – Case Study Of Malaysia”. Issue 4, Volume 4, April 2008. ISSN: 1790-5079.


60

Documents

Malaysian Solar Iradiation 2010