Energy efficiency can bolster regional or national energy security. By reducing overall energy demand, efficiency can reduce reliance on imports of oil, gas and coal. Energy efficiency can therefore play a crucial role in ensuring both long- and short-term energy security in a cost-effective manner.

Energy efficiency also reduces the likelihood of supply interruptions; the only energy source that cannot be interrupted is the energy that is not used. Also, in the event of a disruption, efficiency measures can work with emergency conservation measures to reduce demand. This was demonstrated effectively in the wake of the Great East Japan Earthquake of 2011.1

Energy efficiency reduces the amount and cost of energy imports

In IEA countries and other major economies, efficiency gains since 2000 avoided the need for over 11 EJ or 20% more fossil fuel imports in 2017, of which avoided oil imports in IEA countries alone were worth over USD 30 billion. Lower imports also bring broader macroeconomic benefits, including an improved balance of payments and increased competitiveness.

Reduction in fossil energy imports in IEA countries and major emerging economies due to efficiency improvements since 2000 by fuel

Reduction in fossil energy imports in IEA countries and major emerging economies due to efficiency improvements since 2000 by fuel

Note: Countries covered are IEA countries plus China, India, Brazil, Indonesia, Russian Federation, South Africa and Argentina.

Among the IEA member countries most dependent on imports of oil and gas, Japan’s import savings from energy efficiency are the largest. This reflects Japan’s dependence on oil and gas imports and its long history of rigorous efficiency policies, especially fuel efficiency standards for passenger vehicles and heavy duty vehicles. Oil savings in Japan were equivalent to more than 20% of its oil imports in 2016 and nearly three times greater than oil savings in Germany, which has the second-largest oil import savings. Although gas import savings in the United Kingdom were slightly smaller than in Japan in absolute terms, they were much larger relative to total imports, reaching over 80% in 2016. This reflects the fact that the United Kingdom uses local resources to meet more than 50% of its domestic gas demand.

Reductions in energy imports in 2016 from efficiency improvements since 2000 in the largest IEA member country importers

Reductions in energy imports in 2016 from efficiency improvements since 2000 in the largest IEA member country importers

Reducing energy imports (or increasing exports) through efficiency can also benefit a country economically, particularly where energy is a large contributor to trade balances, by improving national accounts and reducing the need for costly supply and storage infrastructure. Reductions in electricity demand resulting from efficiency can also limit requirements for new electricity generation, transmission and distribution infrastructure, particularly during a transition from fossil fuels to renewables-based generation.

Energy efficiency has substantially reduced European gas imports

The impact of energy efficiency improvements on gas imports has been particularly striking in the European Union, which accounted for more than half of imports by IEA member countries in 2016, and where domestic production has been declining in recent years. In 2016, the primary sources of gas imports to the European Union were Russia, Norway and Algeria.2

Energy efficiency gains since 2000 in Germany and the United Kingdom – the two largest EU gas markets – have been the main factor behind lower gas use and the reduced need for imports. Between 2000 and 2015, overall gas demand fell by 11% in Germany and 29% in the United Kingdom. This decline more than offset the impact of factors that drove up gas demand, including increases in population, number of households, economic growth and changes in fuel mix.

Had the efficiency of gas demand in the residential, industrial and services sectors not improved since 2000, gas consumption in 2015 would have been 21% higher in Germany and 27% higher in the United Kingdom. The savings from these two countries alone are equivalent to nearly a quarter of the European Union’s entire gas imports from Russia in 2015.

In both countries, the bulk of the savings came from efficiency improvements in the residential sector, particularly in space heating. Between 2000 and 2015, the amount of gas needed for space heating per unit of floor area fell by 44% in Germany, saving 11.5 billion cubic metres (bcm), and by 28% in the United Kingdom saving 7.5 bcm.

Decomposition of gas demand, 2000-15##efficiency2017##

Decomposition of gas demand, 2000-15

Notes: Residential factors combine changes in residential floor area, population, the number of households and the fuel mix. For the United Kingdom, electricity generation refers to the shift from gas-fired generation to other fuels and technologies.

Efficiency helped contribute to emergency response in Japan

Energy efficiency and conservation efforts played a major role in Japan’s response to the energy emergency that resulted from the Great East Japan Earthquake in 2011. The magnitude 9 earthquake and the subsequent tsunami on 11 March 2011 caused widespread devastation and significant loss of life in north-east Japan. This natural disaster also triggered a serious accident at the Fukushima Daiichi nuclear power plant – level 7, the most severe on the international nuclear event scale. Significant off-site radiation was released from fuel meltdowns in the three reactors in operation at the time at the six-unit facility. As a result of the accident and investigations into its causes, the remaining 48 operational nuclear reactors in Japan were gradually taken offline during regularly scheduled maintenance outages, leading to a shortfall in electricity supply in the country.4

To rectify the supply shortfall and compensate for the loss of Japan’s nuclear capacity, power generation from coal, oil and gas-fired plants was increased, and energy savings measures were implemented. Energy savings measures initially focused on emergency conservation, called “Setsuden” (saving electricity), in the service area of the Tokyo Electric Power Company (TEPCO), which was most directly affected by the nuclear shutdown. These were successful in avoiding blackouts over the summer peak time in 2011 and 2012.

Japanese energy conservation measures following the Great East Japan earthquake and Fukushima nuclear disaster5

Year Description of measures
2011 For 10 weekdays between 14 March and 28 March, planned power outages were executed across the TEPCO service area, which was heavily affected by the nuclear shutdown.
In August, large electricity users in the TEPCO area were forced to limit electricity use in accordance with the Electricity Business Act.
From July to September, large companies and factories were required to cut electricity use by 15% compared with the previous year.
2012 During summer and winter, consumers were required to save electricity through the continuation of the mandatory requirement to meet numerical targets for electricity savings.
2013 In May 2013, a partial amendment was implemented to the Act on the Rational Use of Energy allowing for the adoption of peak demand shift, giving large electricity consumers, particularly in industry, incentives to shift times of peak demand.
2013-15 Unlike the requirements in 2011 and 2012, savings were not governed by numerical targets.
  1. IEA, Saving Electricity in a Hurry, 2005. Available online:

  2. Eurostat (2017), Eurostat Energy Database, Eurostat, Brussels,

  3. IEA, Energy Efficiency Market Report, 2017.

  4. IEA (2017b), CO2 Emissions from Combustion 2017, OECD/IEA, Paris,

  5. Yoshikawa (2017), Energy Efficiency and Conservation Policies after the Great East Japan Earthquake in Japan.