Synergies between renewable energy and energy efficiency

Energy-related emissions represent two-thirds of greenhouse gas (GHG) emissions. Immediate action is needed to start putting the world on a path to net-zero emissions, as per the Paris Agreement.

Renewable energy and energy efficiency will work in synergy to drive global energy decarbonisation. When pursued together, they result in higher shares of renewable energy, a faster reduction in energy intensity, and lower energy system costs. This also brings environmental and social benefits, such as less air pollution.

This working paper by the International Renewable Energy Agency (IRENA) considers how renewables and energy efficiency can work together to contribute to global energy decarbonisation by 2050. It also looks on how this synergy affects energy system and technology cost, and the effect it has on air pollution and avoidance of adverse health effects caused by these pollutants.

The paper looks in detail at the five largest energy users – China, Germany, India, Japan and the United States – up to 2030. Together, these five countries represent two-thirds of the G20’s primary energy supply and around half of global energy demand.

Global energy-related carbon dioxide (CO2) emissions could be reduced by 70 percent until 2050, with a net positive economic outlook, according to Perspectives for the Energy Transition: Investment Needs for a Low-Carbon Energy System, a joint study by IRENA and the International Energy Agency (IEA). Renewables would account for about half of total emission reductions, with another 45 percent coming from increased energy efficiency and electrification.

Maximising such synergies requires a greater understanding of the potential that exists at the country, sector and technology levels. It also calls for a system-wide perspective, taking account of inter-linkages between technologies and sectors.

IRENA’s working paper proposes actions to strengthen synergies as a step towards a sustainable and affordable energy future. The annex provides in-depth technical findings for the five countries.

The paper also forms parts of IRENA’s global renewable energy roadmap analysis. For more information please visit


  • Emissions & Mitigation
  • Energy


  • Air pollution
  • Decarbonisation
  • energy
  • Energy costs
  • Energy efficiency
  • Energy intensity
  • Health
  • renewable energy
  • Renewables