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The world’s largest untapped energy source: Excess heat

There is a greener and safer route out of the energy crisis. In the newest edition of Danfoss Impact, the untapped potential of excess heat is being addressed together with solutions, which can help utilize wasted energy from excess heat.
24 February 2023

In Europe, decision-makers are still struggling to close the gap between energy supply and demand left by the cut-off from Russian gas. Countries are taking reactive emergency measures, such as firing up old coal-fired power stations, as well as signing new nuclear and liquefied natural gas (LNG) leases.

Sadly, decision-makers overlook that there is a readily available, greener, cheaper and safer alternative, namely, smarter use of the energy we already have. One way to do that is by using the vast amounts of energy that are currently wasted across sectors.

Wasted energy often comes in the form of excess heat and is a byproduct of most industrial and commercial processes; factories, data centers, wastewater facilities and supermarkets all produce vast amounts of excess heat. In the European Union (EU) alone, excess heat amounts to 2,860 TWh/y, almost corresponding to the EU’s total energy demand for heat and hot water in residential and service sector buildings. Much of this excess heat could instead be captured and used.

We already have the solutions available today – what we need now is the political will to make it happen. The greenest, cheapest, and safest energy is the energy we don’t use.

Let’s get started.

Key takeaways:

Only got 2 minutes? These are the key takeaways:


Excess heat is the world’s largest untapped source of energy

In the EU alone, excess heat amounts to 2,860 TWh/y, almost corresponding to the EU’s total energy demand for heat and hot water in residential and service sector buildings. Much of this excess heat could instead be captured and reused.


The solutions already exist

Heat recovery technologies exist that can use excess heat from industries, wastewater facilities, data centers, supermarkets, metro stations and commercial buildings. Excess heat can be reused to supply a factory with heat and warm water or exported to neighbouring homes and industries through a district energy system. This paper presents concrete policy measures to accelerate the use of excess heat across sectors, benefitting citizens and businesses with lower energy costs and accelerating the green transition.


Reusing excess heat is energy efficiency in its purest form

A global push for higher efficiency can help avoid almost 30 million barrels of oil per day (that corresponds to triple Russia’s average production in 2021) and 650 bcm of natural gas per year – around four times what the EU imported from Russia in 2021.

Discover the white paper

You should consider reading

District energy
District heating
Energy efficiency
Energy efficiency in buildings
Energy efficiency in industry
Heat storage
Surplus heat


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