PHOTOVOLTAIC SOLAR ENERGY. Based upon the photoelectric effect to transform light from the Sun directly into electricity. When sunlight affects the photovoltaic cell, the electrical charges on the inside of the silicon panel are freed and regroup on the surface, on one side positive and the other negative. If this electrical circuit is closed, the charges leave the cell and create an electric current. IBERDROLA RENOVABLES has photovoltaic energy installations in Spain and Greece.

PIPELINE. See PROJECT PORTFOLIO.

POLLUTION. LIGHT POLLUTION is the effect of the inappropriate or excessive use of artificial lighting by humans. The reflection of this light in the air’s gases and suspended particles produces brightness in the night sky. ATMOSPHERIC POLLUTION is the presence in the air of matter or forms of energy which cause damage to people, fauna and flora, or any natural assets.

POWER. Standard unit is the watt. Quantity of work done per unit of time. Equals the speed of the change of energy in a system or the time employed in carrying out the work.

PRODUCTION. Manufacture or creation of a product. Creation and processing of goods and merchandise, including their conception, processing at various stages and the financing offered by banks. Considered to be one of the main economic processes, through which human work creates wealth. As far as production problems are concerned, both private and public sector producers have to take into account various economic laws, data on prices and available resources. The materials or resources used in the production process are known as production factors.