L'energy efficiency expresses the ability to use thepower in the best way, intervening above all on the final uses represented by industry, transport, agriculture and housing. Objective of theenergy efficiency is to consume energy better.
On the subject of buildings, those high energy efficiency they are designed and built according to two principles: no energy waste, maximum exploitation and optimization of renewable energy resources.
A little different is the energy saving, whose goal is to consume less. Sure if you do efficiency it consumes even less, and here lies the link - very subtle - between the concepts of energy efficiency and energy saving.
Energy saving is for example summer time, which allows us not to waste millions of KWh. Saving is also turning off the lights when they are not needed and heating the water with solar thermal panels and heat pumps instead of with electric water heaters (which do not shine for energy efficiency).
Returning to the buildings, via the energy certification you can understand how they were created from the point of view of insulation, insulation and heating and cooling systems, lighting and domestic hot water; that is, you can understand how the building can contribute to energy saving.
Energy certification is the basis of energy classification of buildings (A, B, C, D, E, F, G) that can be improved through the technical and economic study of possible interventions, i.e. through a energy audit (which can consist of a pre-audit or an advanced audit). The energy classification, with a similar criterion, also exists for household appliances.
Still on the subject of buildings, possible interventions for the improvement ofenergy efficiency for example: interventions on the building envelope, the installation of a photovoltaic system, the installation of a cogeneration system, the installation of heat pumps and the use of low-consumption light sources (LED).
Why is theenergy efficiency? Because waste and energy losses represent a hidden resource thatenergy efficiency allows us to use in economic, environmental and social terms. With the'energy efficiency we can reduce energy costs (here is energy saving again) both at the individual level (savings visible in the bills of businesses and citizens) and at the general level (savings on the national bill and less pollution).