Energy efficiency is a way of using less energy to provide the same service. Energy efficiency is the goal of managing and restraining the growth in energy consumption. According to the EIA (International Energy Agency) “something is more energy efficient if it delivers more services for the same energy input or the same services for less energy input”
Reducing energy consumption a reduction in energy costs can be achieved. Reducing energy use is also seen as a solution to the problem of reducing CO2emissions.
According to the EIA improving energy efficiency in buildings, industrial processes and transportation could reduce the world’s energy needs in 2050 by one third, and help control global emissions of greenhouse gases.
Transport is one of the responsible for the burning of fuels such as petroleum. For this reason is very important that we have sustainable transport and sustainable energy production.
The industrial sector requires energy to drive reactions, to create heat, and to obtain mechanical energy (work). However, these reactions have thermodynamic limits.
Buildings take part in the GHG emissions and in energy consumption. In 2010 buildings meant a 32% of total global final energy use and a 19% of energy‐related GHG emissions (approximately one‐third of black carbon emissions).