The electric lighting is responsible for 15% of the electricity consumption, the efficiency in this sector has good progress in recent years, it can still improve more. Conventional energy sources are polluting and limited, so it is essential to use less aggressive energies with the environment. Creative, energy-efficient lighting does more than just look nice; it also can maximize the functionality of your space and save on energy costs. Being “energy-efficient” simply means that you are taking steps to use less electricity or natural gas. Aside from preserving the planet, this also means that you can lower your monthly costs. In lighting, this premise is being implemented in a cross-cutting manner, but in response to varied and sometimes contradictory interests. The development of lighting devices based on solar radiation is an inalienable objective, as is the use of artificial lighting sources that are clean with the environment. To achieve these two objectives, it is essential to know and study the design techniques of non-image optics.
A comprehensive survey is always the best first step. The survey should compile data including an inventory of every light fixture in every room, office, common area or other space, as well as operating hours for those fixtures. Existing controls and lighting level readings should be recorded. CAD files showing floor plans and reflected ceiling plans are a great help, especially for photometric studies and controls layouts.