Sun and wind more useful than you thought
~Wind turbines - a future perspective~
Wind turbines are one of the oldest forms of energy in the world. Developed from the windmills which were used in irigations , wind turbines helped all these ages the humanity. As their name says, wind turbines use wind's power. Winds are formed because the sun doesn't warm uniform the Earth, creating air movements. The kinetic energy from the wind can be used to spin some turbines, which are able to generate electricity. Some of the turbines produce 5 MW, although this requieres a wind speed of 5.5 m/s (20 km/h) . There are few zones on the Earth with such wind speed, but more powerfull winds can be found at high altitudes and in oceanic zones.
In Europe, we get the most suitable weather for renewable energy systems to work. The most common way of getting energy from the wind is through setting up 'Wind farms'.
Wind turbines generally have 3 blades and they rotate at 10-30 revolutions per minute. The blades face into the wind, the wind forces them to go round, which then spins a shaft inside the turbine, which is connected to a generator which produces the electricity.
Advantages: no polution, no waste products, small costs for electricity . These advantages show the massive development of these technology in the last years.
Disadvantages: wind's speed variation (there are many days with no wind, and the turbines may not produce anything), they require waste-land because of their visual and sonor pollution (these turbines induce a strong sound and have a negative visual aspect, whch could affect the ecosystems).
~The sun - hot and ready for action~
Solar energy is energy directly from the Sun. This energy drives the climate and weather and supports virtually all life on Earth. Heat and light from the sun, along with solar-based resources such as wind and wave power, hydroelectricity and biomass, account for most of the available flow of renewable energy.
The use of solar power became very popular in the 1970s, but has fallen in and out of favour since depending on the potential savings when compared with fossil-fuel energy costs. Local councils started fitting council houses with facilities to use solar power. Grants are now available to help homeowners make the switch to renewable energy. Within 10 years photo voltaic cells are likely to be competitive with conventional power sources.
The direct caption of the solar energy supposes different artificial ways, named "solar collectors", which are made to catch the energy. Once catched, the energy is used in thermal, photoelectric or photovoltaic processes.
1. Solar panels
A solar panel is a device that collects and converts solar energy into electricity or heat. It transfers energy from the sun into electricity or heat which can be used by (for example) nearby buildings. Solar panels can be made so that the sun's energy excites the atoms a silicon layer between two protector panels. The atoms split up and the electrons travel down wires into the home for electricity. Solar panels were in use over one hundred years ago for hot water heating in homes. Solar panels can also be made with a specially shaped mirror that concentrates light onto a tube of oil. The oil then heats up, and travels through a vat of water, instantly boiling it. The steam created turns a turbine for power.
In the field of photovoltaics, a photovoltaic module is a packaged interconnected assembly of photovoltaic cells, also known as solar cells. An installation of photovoltaic modules or panels is known as a photovoltaic array or a solar panel. Photovoltaic cells typically require protection from the environment. For cost and practicality reasons a number of cells are connected electrically and packaged in a photovoltaic module, while a collection of these modules that are mechanically fastened together, wired, and designed to be a field-installable unit, sometimes with a glass covering and a frame and backing made of metal, plastic or fiberglass, are known as a photovoltaic panel or simply solar panel. A photovoltaic installation typically includes an array of photovoltaic modules or panels, an inverter, batteries (for off grid) and interconnection wiring.