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 light-emitting diode (LED) bulb uses less energy than an incandescent bulb to produce the same amount of light, therefore the LED is considered to be more energy efficient.

What are the IEA 25 energy efficiency policy recommendations?

‌The IEA promotes energy efficiency policy and technology in buildings, appliances, transport and industry, as well as end-use applications such as lighting. IEA analysis has led to the development of 25 energy efficiency policy recommendations which identify best-practice, highlighting the opportunities for energy efficiency improvements and policy approaches in each sector to realise the full potential of energy efficiency for IEA member countries. The IEA has also partnered with regional experts and organisations to develop specific energy efficiency policy recommendations for the Arab-Southern and Eastern Mediterranean (SEMED), Southeast Asia, Latin America and the Caribbean Regions and for the Ukraine.

What are the multiple benefits of energy efficiency?

The term “multiple benefits” aims to capture a reality that is often overlooked: investment in energy efficiency can provide many different benefits to many different stakeholders. These benefits have been variously labelled “co-benefits”, “ancillary benefits” and “non-energy benefits” – terms often used interchangeably with “multiple benefits”. The IEA uses the term multiple benefits, which is broad enough to reflect the heterogeneous nature of outcomes and to avoid pre-emptive prioritisation of various benefits; different benefits will be of interest to different stakeholders.

The multiple benefits of energy efficiency include: energy savings, GHG emissions, energy security, energy delivery, energy prices, macroeconomic impacts, industrial productivity, poverty alleviation, health and well-being, employment, local air pollution, resource management, public budgets, disposable income and asset values. This list is not exhaustive, but represents some of the most prominent benefits of energy efficiency.

For more information see our publication on Capturing the Multiple Benefits of Energy Efficiency

What is energy efficient prosperity?

Energy efficient prosperity was launched at UNFCCC COP21 in 2015 and aims to build on the multiple benefits of energy efficiency with the ability for energy efficiency to enable improved standards of living and to contribute to economic and social development. Energy efficient prosperity includes benefits such as: Improved productivity, improved comfort, energy security, job creation, improved air quality, public budgets, local investment, and improved mobility. This list is not exhaustive, but represents some of the most prominent benefits of energy efficient prosperity.

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:

Regulation: The main regulatory instruments for buildings include building energy codes and minimum energy performance standards.

Information: The main information policy tools for buildings include labels, certificates and disclosures.

Incentives: Incentives are used to help increase the attractiveness of energy efficiency investments. Incentive policies include all financial and non-financial incentives and disincentives to enable increased energy efficiency.

 What does S&L stand for?

In energy efficiency policy, S&L stands for standards and labels, which can be associated with any energy-using technology, including for buildings, vehicles and industry, but is most commonly associated with the lighting, appliances and equipment. Standards can include both minimum energy performance standards (MEPs) and high energy performance standards (HEPs). Labels can include any method of standardised information sharing that enables a consumer to understand the potential energy impact of an energy-using technology.

What is an energy performance certificate?

An energy performance certificate is a document that provides information on a building, including the energy use and often a rating that enables comparison between multiple buildings.  Energy performance certificates also often include basic information on the building such as the address, building type, floor area and date of certification.

What is an energy disclosure?

An energy disclosure is a policy that enables energy use to be reported to a common system, such as a disclosure to a government programme.  The disclosure of energy use can assist government organisations through increased data collection and analysis for developing effective policies.

What do ZEB, nZEB and VLEB mean?

Acronyms such as ZEB, nZEB and VLEB are all associated with highly efficient buildings that have minimal impact on the climate from an energy and emissions basis. There are numerous potential definitions for the acronyms, including the following:

  • ZEB: zero energy building or zero emission building
  • nZEB: nearly ZEB or net ZEB
  • VLEB: very low-energy building or very low-emission building

Buildings can be designed as ZEB, nZEB or VLEB by assessing how the building will integrate into its environment. It is not always possible to reach zero energy demand, however it is often possible to be net zero energy or emissions. To realise the maximum energy demand savings, it is necessary to adopt a holistic approach to ensure that every part of the building is considered. The process involves working on the layout and orientation of the building along with designing the overall building envelope (roofs, walls, windows) to enable minimal space comfort demand. The next step is to include the most efficient lighting, appliances and equipment to ensure minimal energy use. The final step is to include renewable energy to reach net zero energy or net zero emissions.

What is a Deep Energy Retrofit (DER)?

Deep Energy Retrofit is defined by IEA’s EBC-TCP Annex 61 as a major building renovation project in which site energy use intensity, including plug loads, has been reduced by at least 50% from the pre-renovation baseline.