4.2. Solar energy
Solar energy is the most promising source of clean, renewable
energy and it has the greatest potential of any power source to
solve the world’s energy problems [34]. Although solar power
producing devices have been around for over 50 years, solar
electricity devices often referred to as photovoltaic (PV) are still
considered as cutting edge technology. Globally, there are about
1700 TW of solar power are theoretically available over land for
photovoltaic (PV). The capture of even 1% of this power would
supply more than the world’s power needs. Cumulative installed
solar PV power at the end of 2007 was 8.7 GW, with less than 1 GW
in the form of PV power stations and most of the rest on rooftops
[35]. The capacity factor of solar PV ranges from 0.1 to 0.2,
depending on location, cloudiness, panel tilt and efficiency of the
panel. Current technology of PV capacity factors rarely exceed 0.2
based on calculations that account for many factors, including solar
cell temperature, conversion losses and solar isolation [36].
Photovoltaic systems have a number of merits and unique
advantages over conventional power-generating technologies.
PV systems can be designed for a variety of applications and
operational requirements, and can be used for either centralized or
distributed power generation. Energy independence and environ-
mental compatibility are two attractive features of PV systems. The
fuel (sunlight) is free and no noise or pollution is created from
operating PV systems. In general, PV systems that are well
designed and properly installed require minimal maintenance and
have long service lifetimes. However, at present, the high cost of PV
modules and equipments are the primary limiting factor for the
technology.
Solar power or also known as photovoltaic system is estimated
to be four times the world fossil fuel resources in Malaysia [37]. The
climatic conditions are favourable for the development of solar
energy due to the abundant sunshine throughout the year. In
Malaysia, the tropical environment has been characterized by
heavy rainfall, constantly high temperature and relative humidity.
The annual average daily solar irradiations for Malaysia are from
4.21 kWh/m2 to 5.56 kWh/m2 [38]. The highest solar radiation was
estimated at 6.8 kWh/m2 in August and November while the
lowest was 0.61 kWh/m2 in December. The Northern region and
a few places in East Malaysia have the highest potential for solar
energy application due to its high solar radiation throughout the
year. A PV system consists of several solar cells that convert light
energy into electricity. PV is an elegant means of producing
electricity on site, directly from the sun without concern for
fuel supply or environmental impact. Solar power is produced
silently with minimum maintenance, no pollution and no
depletion of resources. PV system is also exceedingly versatile
and can be used to pump water, grind grain and provide
communications and village electrification in situations where
no electricity is available [6].
Currently, solar energy applications mostly oriented towards
domestic hot water systems, water pumping, drying of agricultural
produce. Most of the solar power used in Malaysia is on domestic level only and large scale commercial use is not significant yet. It is
estimated that there are more than 10,000 units of domestic hot
system using PV system at the moment in Malaysia [39]. Although
PV system has tremendous potential, especially for remote areas in
Malaysia, the cost of PV panels and technology are extremely high
for mass power generation. The current market value of PV system
is about RM 28.00/Wp (US$ 8.40) [40]. Due to the high initial cost of
PV system, Malaysia does not have any local PV manufacturer. All
the PV modules and inverters are imported from foreign countries
like Germany and Japan, hence causing the cost of PV systems to be
very high. As a result, PV systems are not an attractive option to the
public.