Desalination technique used in this project is distillation process。 Distillation is a process that converts raw water by using heat sources to separate it from undesirable elements through vaporization。 The water vaporizes at constant temperature and condenses to liquid form, thus leaves the remaining elements that require higher boiling point in the form of sediments。 Furthermore, this process removes disease- causing bacteria through the vaporization process。 Since the early years, people have tried to use solar power  for distillation process [3]。 As the heat source to initiate the vaporization process is quite costly, thus solar power is an alternative to boost up the distillation process in an efficient and unpolluted manner。

III。METHODOLOGY

The design of photovoltaic power system consists of solar PV panels and batteries as back-up of the system。 The solar energy supplied is hourly basis because of the fluctuating parameters of solar energy available in the locations selected。

A。Site Selection

The location of the project is quite important since this paper is on renewable power system。 The consideration was made to maximise PV energy production。 Kuala Perlis is chosen as the main area which is a coastline region located by Malacca Strait at 6° 24' north and 100° 8' east。 Due to its tropical climate, Kuala Perlis provides abundant sources of solar energy。 Table I is the monthly solar irradiance available and the clearness index for Kuala Perlis。 These data were retrieved from HOMER Energy Modelling software。 These meteorological data were calculated by using the latitude of the location with Graham algorithm。 Hence, a synthetic data sequence will be obtained for hourly and daily which the graphical representation of total solar irradiance at Kuala Perlis is shown in Fig。 3。

As shown in Fig。 3, there is a significant high amount of solar irradiance in Kuala Perlis with a daily solar irradiance scaled annual average 5。27 kWh/m2-day and average clearness index of 0。53。 The lowest solar insolation occurs in November which is 4。757 kWh/m2-day。 In this paper, Peak-Sun approach is used to estimate the solar energy production by using the lowest solar insolation as stated above。

Fig。 3。 Total solar irradiance and clearness index for Kuala Perlis。

B。Load Profile

The load profile is a summary of total electrical energy required to operate the desalination mini plant。 Some assumptions were made to determine the load profile which is the desalination mini plant constantly operates at 24/7 under full load condition。 The important design for the desalination process is to increase the vapor pressure in order to facilitate the vaporization and condensation phase。 Fig。 4 illustrates the vapor pressure increases exponentially with every increase of temperature。 Daily load demand for desalination plant is tabulated in Table I。

Fig。 4。  Vapor Pressure of Water (Based on Dortmund Data Bank)。

TABLE I。 DAILY LOAD DEMAND

Load Power Consumption Total Power Consumption (Wh/day)

Heater and sensors

800 W

800 x 24 = 19200

C。Design Calculations

For a starting point of the analysis, the total ac power demand would be 800W which draws 67A when the system voltage is 12V。 A 12V inverter is suitable for this desalination plant because it can cater future power growth in future as it is still satisfied the 100A guideline。 Table II represents the system voltage suggestion based on limiting maximum steady state current to 100A [4]。

Short Term Grant UniMAP Reference No。 9001-00253

TABLE II。 海水淡化的优化设计英文文献和中文翻译(2):http://www.youerw.com/fanyi/lunwen_100584.html