Solar Address

Solar energy refers mainly to the use of solar radiation for practical ends, such as a solar address or solar sign. However, all renewable energies (other than geothermal and tidal) derive their energy from the sun. The radiant light and heat from the Sun has been used by humans for a very long time. Solar energy along with other resources such as wind and wave power, hydroelectricity and biomass account for most of the available renewable energy on Earth. However, only a minuscule fraction of the available solar energy is used. Generation of energy by means of heat engines or photovoltaics provides electricity once converted. Its uses are only limited by ingenuity. It can be used for applications such as 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.

There is always a cost however and for a long time the use of non-renewable resources has been seen as cheaper. Three factors need to be considered when assessing the cost: Capital costs such as waste disposal and decomissioning costs for nuclear energy, operating and maintenance costs, and fuel costs.

Solar Energy Facts

The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere.[5] 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. The energy received from the sun effects ocean currents, wind, rain, heats the surface, and feeds the Earths vegetation. The 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.

The total amount of energy absorbed by Earth's atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the world used in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass. The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earth's non-renewable resources of coal, oil, natural gas, and mined uranium combined. It would appear that solar, wind or biomass would be sufficient to supply all of our energy needs, however, the increased use of biomass such as coal has had a negative effect on global warming and dramatically increased food prices by diverting forests and crops into biofuel production. As intermittent resources, solar and wind raise other issues.

Solar technologies (of which a solar address is an example) are broadly characterized as passive or active depending on the way they capture, convert and distribute the sunlight. Active solar techniques use photovoltaic panels (used in solar powered signs), pumps, and fans to convert sunlight into something useful. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.