- Issue date: 20/02/2009
- Printing Process: Huecograbado
- Paper: Estucado, engomado, fosforescente
- Size of stamp: 24,88 x 28,8 mm. (verticales)
- Book size: 158 x 86,4 mm. (horizontales)
- Postal value of the stamps: 0,32; 0,43; 0,62 y 0,78 €
- Print run: Ilimitada para los cuatro valores postales
- Dented: 12 3/4 horizontal y 13 1/4 vertical
Renewable energy is energy generated from natural resources, such as sunlight, wind and rain which, and are naturally replenished. Since three decades ago, they are considered as alternative to the traditional ones since renewable energy quickly replaces itself and is usually available in a never-ending supply and has a minor impact on the environment. This issue is made up of four stamps devoted to four of the main renewable energy technologies: Hydropower, Wind power, Solar energy and Geothermal energy.
Hydropower, is power that is derived from the force or energy of moving water, such as rivers, water falls and tides. which may be harnessed for useful purposes. Hydropower through waterwheels, has been used for hundreds of years to power mills and machinery. Currently hydroelectric power is the main source of renewable energy.
Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines. From ancient times it has been used to propel sailboats and axels in windmills and is currently one of the main energy producing systems with high levels of penetration. The principal application of wind power today is the generation of electricity mainly through large scale wind farms.
Solar energy is the light and radiant heat from the Sun and refers to the electricity generated from solar radiation. The process consists in processing solar radiations through photovoltaic panels to convert it to thermal or electrical energy. This system is very useful in isolated and remote areas where there is no electrical supply. In Europe, the main countries which produce this type of energy are Greece, Germany, Austria and Spain.
Geothermal energy is obtained by tapping the heat of the earth, usually from kilometers deep into the Earth's crust. This energy takes the form of hot steam or hot water mixed with chemicals that come out as hot springs or geysers. The hot water or heat can arise naturally or be artificially pumped. Iceland is the main producer in Europe of geothermal energy.