Energy efficiency

What is energy efficiency?

Something is more energy efficient if it delivers more services for the same energy input, or the same services for less energy input. For example, a compact fluorescent light (CFL) bulb uses less energy than an incandescent bulb to produce the same amount of light, therefore the CFL is considered to be more energy efficient.

What are the IEA 25 energy efficiency policy recommendations?

To support governments with their implementation of energy efficiency, the IEA recommended the adoption of specific energy efficiency policy measures to the G-8 summits in 2006, 2007 and 2008. The consolidated set of recommendations to these summits covers 25 fields of action across seven priority areas: cross-sectoral activity, buildings, appliances, lighting, transport, industry and energy providers.  The recommendations can be found here.

Where can I find out more about energy efficiency?

The IEA energy efficiency website offers helpful hints on how to save on energy in everyday life.

How much of the world’s energy is consumed by buildings?

Buildings represent 32% of total final energy consumption. In terms of primary energy consumption, buildings represent around 40% in most IEA countries.

What does primary energy consumption mean?

Primary energy consumption refers to the direct use of energy at the source, or supplying users with crude energy which has not been subjected to any conversion or transformation process.

What does final energy consumption mean?

Final energy consumption refers to energy that is supplied to the consumer for all final energy uses such as heating, cooling and lighting.

How much energy do electronics and computers consume in buildings? 

Consumer electronics and computer equipment now represent 15% of global residential electricity consumption. Energy used by these devices is expected to triple by 2030 unless actions are taken to increase energy efficiency.

What are the main policies to reduce energy demand in the buildings sector?

There are three types of policies that address energy consumption in buildings:

Regulatory instruments: The main regulatory instrument is the building energy code, which is a set of minimum energy performance requirements. The purpose of the energy code is to ensure that a building’s energy performance is considered during the design stage of a building project. (Building energy codes are mandatory in the European Union and often voluntary in other countries).

Information instruments: Labels are the best-known information policy tool used for both appliances and buildings.

Incentive schemes: They are complementary policies to regulatory and information instruments used to help increase the attractiveness of energy efficiency investments. They include all policy instruments that relate to fiscal, financial and other economic incentives and disincentives to deliver energy efficiency improvements. Their objective is to motivate consumers to pursue investments they would not have ordinarily considered.

 What does S&L stand for?

  • Standard (Minimum Energy Performance Requirements, MEPs)
  • Labels.

This abbreviation is mainly used for appliances, lighting and equipment and very rarely for buildings.

What is an Energy Performance Certificate?

It is the European mandatory energy label for buildings.

What does Zero Energy Building (ZEB) mean?

Although this is not yet a standardised definition, common agreement is based on the fact that a Zero Energy Building should refer to a building with very low energy demand, and that the energy consumed is primarily supplied by renewable sources.

Can Zero Energy Buildings be built in any climate and for any type of building?

Yes. New buildings can be designed from the outset as Zero Energy Buildings.  This involves assessing how the building will integrate into its environment. (For example, if a building is near a mountain, this will determine where the windows are placed to ensure maximum exposure to sunlight in cold climate). The process also involves working on the design and overall shell (roofs, walls, windows) of the building. The last step is to use the most efficient appliances and equipment.

For existing buildings, it’s not always possible to reach Zero Energy demand. However, each time a building is retrofitted, it is necessary to adopt a holistic approach and start with the shell to ensure every part of the building is considered in order to realise the maximum energy savings potential.

What does passive house mean?

Passive house refers to a widely-used German energy label. It is a voluntary label with stringent energy requirements; it requires keeping the overall energy consumption of a building below 120 kilowatt-hours per square metre per year (this is around one-third of energy demand in the average household in the United States and almost half of energy demand in the average household in the European Union). The passive house label was originally only used for residential buildings but it is now increasingly also used for non-residential buildings, such as office buildings and schools. 

Do electricity and gas providers help their customers to save energy?

Yes. In 2010, energy utilities in North America alone invested over USD 7 billion. Gas and electricity providers in the United Kingdom, Italy and France spend almost USD 2 billion per year on energy efficiency improvements. These programmes are increasingly targeted not only to households but business, industry and even transport.