World Energy Outlook 2018

WEO 2019
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Energy efficiency


Energy efficiency is one of the cornerstones of any strategy to guarantee sustainable and inclusive economic growth. It remains one of the most cost-effective ways to enhance security of energy supply, to boost competitiveness and welfare, and to reduce the environmental footprint of the energy system. Not only can the growth of carbon emissions be tempered by the more efficient use of energy but energy efficiency can also improve local pollution and contribute to reducing the millions of air-pollution related premature deaths each year, and keep consumers energy bills in check.

Outlook by scenario

Energy intensity of GDP in the Sustainable Development Scenario, 2017-2040


Energy intensity of GDP in the New Policies Scenario, 2017-2040


In the absence of existing and announced efficiency measures, global energy consumption in 2040 would be almost 30% higher than projected in the New Policies Scenario (NPS). Energy efficiency policies in developing economies account for 60% of the reduction in global energy consumption in 2040, but only in the European Union, Japan, and Korea do energy efficiency gains fully offset the increase in energy demand.

In the Sustainable Development Scenario (SDS), the systematic pursuit of economically viable opportunities to improve efficiency keeps the increase in global final energy consumption to around 250 Mtoe in the period to 2040, compared with nearly 2 900 Mtoe in the New Policies Scenario (NPS). In the SDS, energy intensity declines by 3.4% a year, compared with 2.3% in the NPS from 2017 to 2040.

In the SDS, thanks to strong efficiency policies including performance standards and building codes, energy consumption in the buildings sector falls by around 190 Mtoe over the outlook period. Even though growth in industrial energy demand slows in the NPS, growth in the SDS slows even further, to an annual average of 0.5%. Finally transport demand in the SDS decreases by 6%, despite a large increase in demand for mobility.

This year’s analysis includes an update of our the Efficient World Scenario (EWS), demonstrating once more that tackling the barriers to energy efficiency investment can unleash this potential and bring significant gains for energy security, economic development and the environment.

In the new EWS, a 3% annual rate of improvement means that the primary energy intensity of GDP is halved by 2040. This is a considerable step up from the average rate of intensity improvement of 2.3% seen in the NPS. It has major impacts on energy consumption of every end-use sector.

To explore the Efficient World Scenario in more detail, visit Energy Efficiency 2018.


Annual average change in energy intensity by region and scenario, 1990-2030


The United Nations Agenda for Sustainable Development (2030 Agenda) includes targets to improve energy efficiency (Sustainable Development Goal 7.3). Global energy intensity, defined as the ratio of primary energy supply to GDP, is the indicator used to track progress on global energy efficiency. The original target was an annual reduction of 2.6% although the world has fallen short of this goal since it was announced: the annual reduction in 2017 was only 1.7%. This shortfall means that the required rate of intensity improvement has risen to 2.7% for the remaining years to 2030.

Electricity consumption in advanced economies, 2000-2017


Improvements in fuel efficiency of the global car fleet are the single largest contributor to moderating oil demand growth in cars in the NPS. These measures avoid around 9 mb/d of oil demand in 2040. Not all these savings are dependent on technological advances: for example, bringing the fuel efficiency of the global car fleet in line with that of cars in the European Union today (7.3 litres/100 km) would reduce global oil consumption by almost 6 mb/d.


In advanced economies, new sources of electricity demand growth such as digitalization and electrification of heat and mobility have been outpaced by savings from energy efficiency. In the absence of energy efficiency improvements, electricity demand in advanced economies would have grown at 1.6% per year since 2010, instead of 0.3%. Energy efficiency measures adopted since 2000 saved almost 1 800 TWh in 2017 or the equivalent of around 20% of overall current electricity use.