solar energy

Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient
times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources
such as wind and wave power, hydroelectricity and biomass account for most of the available renewable
energy on Earth. Only a minuscule fraction of the available solar energy is used.
Solar power technologies provide electrical generation by means of heat engines or photovoltaics. Once
converted its uses are only limited by human ingenuity. A partial list of solar applications includes space
heating and cooling through solar architecture, potable water via distillation and disinfection,
daylighting, hot water, thermal energy for cooking, and high temperature process heat for industrial
purposes.
Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute sunlight. Active solar techniques include the use of photovoltaic
panels, solar thermal collectors, with electrical or mechanical equipment, to convert sunlight into useful
outputs. Passive solar techniques include orienting a building to the Sun, selecting materials with
favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.