Renewable Energy - Solar (Part 1)

Solar energy is the energy derived from the sun in the form of solar radiation (light photons and heat). Solar powered electrical generation relies on photovoltaic and heat engines. A partial list of other solar applications includes space heating and cooling through solar architecture, daylighting, solar hot water, solar cooking, potable water (distillation and disinfection) and high temperature process heat for industrial purposes. Solar energy is a renewable free source of energy that is sustainable and totally inexhaustible unlike fossil fuels which are finite. It is also a non-polluting source of energy and it does not emit any greenhouse gases when producing electricity.

There are two types of solar technologies, characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy.

1) Active solar techniques include the use of photovoltaic panels and solar thermal collectors directly to harness the energy and convert it into electrical energy.

2) Passive solar techniques include orienting a building to the Sun, selecting materials with favourable thermal mass (for space) or light dispersing properties, and designing spaces that naturally circulate air to minimize the energy usage during daytime. Passive solar techniques are also known as the green technology.

For active solar techniques, there are two types of solar powered electrical generation, photovoltaic and heat engines:-

1) Photovoltaics (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibits photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing photovoltaic material.

2) The heat engines are drove by Concentrated Solar Power (CSP) systems, the systems that use mirrors or lenses to concentrate a large area of sunlight or solar thermal energy, onto a small area. Electrical power is produced when the concentrated light is converted to heat which drives a heat engine (usually a steam turbine or Stirling engine) connected to an electrical power generator.

Malaysia is located at the equator, received substantial amount of sunlight on average per month. So, Malaysia has a huge solar energy capability in most part of the year (except in the monsoon season). Most of the solar energy is converted into electricity by photovoltaic technology and the rest are passive solar techniques. The CSP systems are not suitable in Malaysia because by the world standards, the solar radiation in Malaysia is among the lowest in the world. Malaysia only have the value of solar radiation about 4.0 - 4.9 kWh/m2/day compared to the other location all over the world that are most potential of solar energy about 6.0 - 6.9 kWh/m2/day.

^{World Solar Radiation Map}