Addressing the Heating Challenge: Developing National Decarbonisation Roadmaps

Kapil Narula

Post Doctoral Researcher, Institute for Environmental Sciences (ISE), University of Geneva

22 January 2021  |   #21.03  |    The views expressed in this post are those of the author and may not reflect those of UNU-CRIS.  

Developments in EU climate policy

In December 2019, the European Green Deal was unveiled with an aim to achieve net zero greenhouse gas (GHG) emissions by 2050 for the European Union (EU). To translate this political commitment into action and to establish a legally binding target for the achievement of this goal, the European Commission (EC) proposed the European Climate Law in March 2020. Paving the road to become the first climate-neutral continent, in December 2020, EU leaders agreed to enhance the target of reducing GHG emissions by at least 55% from 1990 levels (increased from 40% in 2014), by 2030. This is aligned with the Paris Agreement objective to limit global temperature rise below 2°C and preferably within 1.5°C, compared to pre-industrial levels. As a part of the 2030 Climate Target Plan the EC will suggest revisions to various policy instruments aimed at additional emission reductions (expected by June 2021). As a part of the European Climate Law, the EC has also proposed the adoption of a 2030-2050 EU-wide trajectory for GHG reduction and a progress review every five years commencing in September 2023. 

Importance of decarbonising the heating sector

In 2015, nearly 72% of the total global GHG emissions  were attributed to energy use. The global Total Final Consumption (TFC) of energy (in 2015) was around 9,500 million tonnes oil equivalent (Mtoe). Its share by different end uses is shown in Fig. 1. Heating contributed to more than 50% of energy end use. Approximately half of the heat was used to provide Space Heating (SH) and Domestic Hot Water (DHW) for buildings. The remaining was used in industrial processes and other sectors.  

Fig. 1. Share of TFC of energy by end use in 2015

Unlike the electricity sector in countries like Iceland, Switzerland, Sweden, and Norway, where more than 95% of power is generated from non-fossil sources, energy for heating is predominantly derived from fossil fuels. As shown in Fig. 2, renewable sources for heat contributed less than 10% to the global heat supply in 2015.  

Fig. 2. Share of primary energy sources for heat in 2015

It is evident from the above assessment, that the goal of climate neutrality for Europe necessitates an overall transition to renewable energy sources and a demand reduction for heating.  

The low impact of energy policies on heat demand reduction 

Effective energy polices can become drivers for change. EU Member States have adopted various policies, both at the regional and national levels. These policies aim to lower heat demand by a) upgrading buildings to improve energy efficiency b) improving technical efficiency of heating systems c) adopting centralised heating systems and District Heating (DH) and d) replacing fossil fuels with zero carbon sources. However, despite a strong policy push since the past two decades, progress towards decarbonised heating has been painstakingly slow and inadequate.  

While efficiency improvements have led to large energy savings, they have been complemented by a substantial growth in population and activity. Consequently - as Fig.3 indicates - over the past 20 years, residential heat consumption has merely seen a 10% decrease instead of a sharp decline. This implies, unless energy policies for heating are revamped, it is highly unlikely to achieve net zero GHG emissions in the next 30 years.  

Fig. 3. Residential heat consumption in the EU (28 MS)

Challenges and way ahead

High-energy demand from old buildings is due to poor insulation. This can be improved by undertaking building envelope retrofits. However, this process is capital intensive, inconvenient for residents, and there remain capacity constraints. Due to these hurdles, the existing renovation rate for buildings in the EU is less than 1% per year, against the required rate of about 2-3%. Furthermore, although strict regulations are in place to ensure that new buildings score well on energy efficiency, there is a ‘performance gap’ between the expected and actual energy use. In effect, despite energy policies comprising energy codes for buildings, renovation subsidies, and technology standards, the reduction of heat demand in buildings has been challenging.  

Unlike process heat, which requires a temperature of 100-250 degree Celsius in the food, textile and chemical industries, SH and DHW can be supplied to buildings by renewable heat sources (solar, thermal, and geothermal energy) at less than 70 degree Celsius. Electrification of heating is another emerging trend. In addition, technological advancement in heat pumps have enabled the utilisation of ambient heat from water, ground, and air. Cities are also promoting DH (District Heating) networks especially in areas of high heat density. DH is advantageous in integrating multiple renewable sources of heat such as large heat pumps, which can upcycle heat from wastewater treatment plants, use centralised biomass boilers, integrate waste heat from incinerators and allow use of Combined Heat and Power (CHP) plants. Thermal heat storage, coupling of heat, gas, and electricity grids, and delivering heat through low temperature DH systems provides system flexibility and is likely to play a key role in a carbon-neutral heating system.  

Need for national heat decarbonisation roadmaps

At the broader level, EU policy making is good for target setting and building momentum for national policies. EU’s energy policies such as the updated directive on energy efficiency in buildings, provide guidance. Energy saving targets are translated into actions through the National Energy and Climate Plans (NECPs) by the MSs (Member States).  

It is proposed, each MS supplements these NECPs with national heat decarbonisation roadmaps, providing a much-needed focus on decarbonised heating. Such a roadmap should provide detailed statistics on heat demand and supply, outline the scenarios of heat demand in the future, assess the potential of renewable heat sources, examine the cost effectiveness of different technologies to supply renewable heat, and analyse the impact of various parameters on the choice of heating technology and energy carrier. Such an assessment should include both, the temporal and spatial aspects of heating. The impact of existing energy policies for heating should be regularly assessed. A gap analysis between the current and desired trajectory should be undertaken at 5-year-long intervals. This gap needs to be addressed by the adoption of complementary policies.  

Heat Roadmap Europe project provides a starting point to such an assessment by undertaking modelling and mapping of heat demand and supply for 14 Member States. Acting on such an approach, countries like the UK (United Kingdom) and Austria are finalising their national heat strategies.  


Decarbonising the building sector is challenging. The renovation of buildings needs to be prioritized for long-term heat demand reduction; followed by a transition to renewable heat supply sources. National heat decarbonisation roadmaps focussed on the technical and policy aspects of decarbonised heat, should be developed, and implemented by the MSs to pave the path for net zero emissions heating in the next few decades.