Solar energy together with wind power, hydroelectricity and biomass account for most of the available renewable energy on Earth.
Solar technologies are characterized as passive solar and active solar depending on the way they capture, convert and distribute sunlight. Active solar techniques include the use of photovoltaic panels and solar thermal collectors (water heaters) to convert sunlight into useful outputs. Passive solar techniques include designing the building angles to the Sun, selecting special materials with thermal or light dispersing properties, and air circulation.
Solar cells in side a solar panel convert sunlight directly into electricity. When sunlight is absorbed by the semi-conducting materials of the solar cells, the electrons absorb the photons and become liberated from their atoms and flow through the material to produce electricity. This process of converting light (photons) to electricity (voltage) is called the photovoltaic (PV) effect. Thus the solar panel also called as photovoltaic panel.
The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet
Earth's land surface, oceans and atmosphere absorb solar radiation, and this raises their temperature. Warm air containing evaporated water from the oceans rises, causing atmospheric circulation or convection. When the air reaches a high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the Earth's surface, completing the water cycle. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as wind, cyclones and anti-cyclones.Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 °C. By photosynthesis green plants convert solar energy into chemical energy, which produces food, wood and the biomass from which fossil fuels are derived.
SINGAPORE | MALAYSIA | THAILAND | INDIA | INDONESIA | PHILIPPINES | VIETNAM | CAMBODIA | MYANMAR | LAOS | CHINA