Opinion - 19/August/2020

Why do we favour renewables over energy efficiency?

It is beyond discussion that the global climate emergency calls for solutions to reduce greenhouse gas emissions and requires decarbonisation. Often, the spotlight is aimed at renewable energy as the solution, but in fact, we can achieve 44% of the required global reductions by capturing the potential of energy efficiency, argues Lars Knaack of Novenco

The views expressed are those of the author and do not necessarily reflect the position of FORESIGHT Climate & Energy

Investing in existing technologies enables us to become carbon-neutral more cost-effectively and faster than if we solely focus on expanding renewable energy


Imagine if we could achieve the majority of the carbon-emission reduction targets with solutions already at hand. The socio-economic savings by investing in energy efficiency is a route that deserves more attention. If we invest in already-known technologies, we can introduce renewables at a higher pace and in a more cost-efficient way to achieve carbon neutrality.

All fingers point to scaling-up sustainability and developing green cities, sustainable products and lifecycle assessments, plus renewables with improved energy-efficiency as a prerequisite for this development.

Urban areas account for two-thirds of global energy demand and 70% of carbon dioxide emissions. One of the obvious ways to bring down urban energy consumption levels is to invest in energy-efficient heating and cooling in buildings and to electrify transport. If all urban areas and cities in Europe, China and the US invested in energy-efficient buildings, to provide a significant reduction of the energy need for heating and cooling, they would make a significant contribution to keeping global warming within the 1.5°C target.

In Denmark alone, energy-efficient building technologies are expected to reduce CO2 emissions by two million tonnes by 2030, based on an investment of DKK 23 billion (€3 billion).



Cities are in need of a vast number of fans to secure fresh and clean air in tunnels and parking basements, as fire prevention fans, and for heating and cooling in buildings. But today’s current building stock uses outdated technology, including inefficient centrifugal and axial fans with non-optimised aerodynamic design.

New solutions are already available. Some of the latest fans have efficiency levels as high as 92%, where older fans only hit somewhere between 50 to 80%. If we replace these older models with new high-efficiency solutions, it is a quick and financially expedient route. The payback time for new fans is short – one-to-three years, depending on operation hours of the fan – which also reduces the need for investment in renewables afterwards.

New fan solutions are also designed and produced with recyclability in mind, and up to 98% of each unit can be recycled. Additionally, the use of high-tech frequency drives that can run a motor at variable speeds enables intelligent building ventilation, helping to save energy and improve system efficiency.

As they are technologies that have been continually developed and refined, they meet the highest emission and efficiency targets. Replacing old fans would lead to lower heat generation as newer products give off less heat gain and have lower sound levels.




To bring about this change, we have to embed good intentions into the specific product specifications driven by ambitious EU legislation and by companies taking on the responsibility.

This is the only way we can ensure that the goals for high energy efficiency levels are put into practice in the production and supply chain. If green legislation is not ambitious enough and is not embedded in the processes and procedures at a company, city or country level, we will simply not reach the global climate targets.

The potential of investing in energy-efficient and sustainable solutions is evident, but there is a need for legislation to overcome the barrier which the higher cost for raw and recycled materials poses.

The legislation should support green initiatives and products, so the cost difference is only minimal – because, in the end, the initial cost drives the decision to buy new products for the majority of owners and developers.

Do you have a thoughtful response to the opinion expressed here? Do you have an opinion regarding an aspect of the global energy transition you would like to share with other FORESIGHT readers? If so, please send a short pitch of 200 words and a sentence explaining why you are the right person to deliver this opinion to opinion@foresightdk.com.


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