Renewables and energy efficiency – better together than in isolation

Renewables and energy efficiency must work together to maximise their contribution to global energy decarbonisation.
Published: Thu 24 Aug 2017

With energy-related emissions representing around two-thirds of greenhouse gas emissions, the development of renewables and alongside that energy efficiency are key in contributing to the more sustainable use of energy and in turn to meeting the carbon reduction goals.

A recent study from the International Renewable Energy Agency (IRENA) found emerging evidence that combining energy efficiency with renewables deployment has synergies that result in a higher share of renewables and faster reduction in energy intensity.

The reasoning for this is that the accelerated deployment of renewables can increase energy efficiency, while the accelerated deployment of energy efficiency means energy demand is reduced so the same amount of renewable energy results in a higher share of renewables.

IRENA has now further investigated this issue, focusing in on the five largest energy using countries of the G20, namely China, Germany, India, Japan and the United States. Together, these five countries represent two-thirds of the G20’s total primary energy supply and around half of global energy demand.

So, what are the findings?


First and most importantly in a Paris Agreement context, renewable energy and energy efficiency can potentially achieve 90% of the carbon reductions required to limit global temperature rise to a maximum of 2°C above pre-industrial levels. (The remaining 10% would come via fossil fuel switching and carbon capture and storage.)

CO2 emission reduction potential by technology (Source IRENA)

A combined approach offers the most timely and feasible route to decarbonising the global energy system, with both renewable energy and energy efficiency offering roughly the same amount of mitigation potential to 2030 when working in synergy. Working in isolation, they do not achieve as beneficial results.

In general, the effect that energy efficiency has on the share of renewables is found to be greater than the effect renewables has on energy intensity.

Another finding is that all countries can benefit from these synergies and while the cost competitiveness of technologies varies between countries, all would see overall savings to their energy systems.

In China, for example, which showed the greatest savings of the five study countries, these could amount to US$182bn in 2030. In Germany, which showed the least, the 2030 savings are estimated at US$11.3bn.

A further finding is that all countries have significant untapped and economically attractive renewable energy and energy efficiency deployment potential, particularly the latter.

More solar PV, wind, geothermal, bioenergy and solar thermal can be deployed across all sectors in all countries than current plans outline.

Energy efficiency improvement

Energy efficiency can be improved in all sectors, especially by process and heat integration, efficient motor systems, industrial heat pumps, improved building envelopes, efficient lighting and appliances, heat pumps for heating and cooling, electric mobility, efficient gas power plants, and a shift from coal- to gas-fired power plants.

However, greater understanding is required of which countries and regions require which additional technologies to meet the decarbonisation targets.

Presciently, when the Sustainable Energy for All (SE4All) initiative was launched in 2010, alongside the universal access goal, targets were also set for renewable energy growth and energy efficiency improvements.

Now embodied as part of Sustainable Development Goal 7, the targeted improvement in energy efficiency is a doubling in the rate by 2030. However, according to the IRENA report this is a challenge for developed countries – and even more so for developing countries due to the rapidly rising demand. Indeed, in the cases of China and India, this rising demand could result in a deterioration in energy efficiency improvement rates.

Energy system-wide approach

The IRENA study specifies that a system-wide perspective is needed of the synergies between renewables and energy efficiency.

Among the recommendations is a call to develop well-designed initiatives to realise the synergies of the respective technologies across all sectors of the energy system.

The deployment of renewables and energy efficiency technologies should be accelerated in the industrial and transport sectors, In addition, more ambitious technology solutions, including integrated renewable, energy efficiency solutions, should be explored for buildings. As urbanisation increases, cities, and by extension, buildings, will play a growing role in achieving energy and climate goals.

Finally, as the study covers the timeframe up to 2030, longer term planning is needed to 2050 and beyond.

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