Heating in buildings

Tracking Clean Energy Progress

🕐 Last updated Wednesday, 23 May 2018

Not on track

Sales of heat pumps and renewable heating equipment have continued to increase by around 5% per year since 2010, representing 10% of overall sales in 2017. Fossil-fuel equipment, however, still represents 50% of sales; less-efficient, conventional electric heating equipment represents another 25%. To meet the SDS target, the share of heat pumps, renewable heating and modern district heating needs to reach more than one-third of new sales by 2030.


Sales of heating technologies

Carbon-intensive and less efficient heating technologies still represent the vast majority of heating sales globally.

	Renewables	District heating and cooling	Heat pumps	Conventional electric equipment	Fossil fuel equipment
2010	6.527	9.995	2.128	24.493	56.858
2011	6.992	10.661	2.064	24.234	56.048
2012	6.399	13.491	3.947	21.961	54.203
2013	7.044	11.721	2.657	23.162	55.416
2014	7.552	14.409	2.356	22.267	53.416
2015	7.892	14.015	2.326	24.546	51.222
2016	8.030	12.136	2.554	24.890	52.390
2017	8.017	10.849	2.545	25.984	52.606
2025	11.629	10.017	5.823	31.424	41.106
2030	13.463	10.326	7.563	34.858	33.790
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Note: excludes traditional use of biomass.


Energy use for heating has remained stable since 2010, with heating energy intensities decreasing only by around 2.6% per year since 2010 – roughly the same rate as floor area growth.

Much of this is due to energy intensity improvements in major heating markets such as Canada, China, the European Union, Russia and the United States. But fossil fuels still supply most space heating and hot water production needs in buildings. As a result, direct emissions from heating in buildings have remained stable since 2010.

Energy performance of space heating and water heating

Heating energy intensities are decreasing, but at roughly the same rate as floor area growth.

	Eurasia	OECD Europe	OECD Americas	World	Africa	OECD Pacific	Middle East	China	India	Other Asia	Latin America
2000	0.0279	0.0149	0.0106	0.0119	0.0077	0.0082	0.0045	0.0062	0.0059	0.0030	0.0023
2001	0.0272	0.0156	0.0098	0.0116	0.0077	0.0079	0.0049	0.0057	0.0059	0.0030	0.0022
2002	0.0257	0.0149	0.0097	0.0111	0.0076	0.0082	0.0046	0.0054	0.0057	0.0029	0.0022
2003	0.0261	0.0153	0.0098	0.0112	0.0076	0.0078	0.0045	0.0053	0.0057	0.0029	0.0022
2004	0.0252	0.0151	0.0094	0.0109	0.0076	0.0076	0.0046	0.0054	0.0056	0.0028	0.0022
2005	0.0234	0.0149	0.0090	0.0104	0.0075	0.0077	0.0048	0.0052	0.0054	0.0027	0.0022
2006	0.0236	0.0146	0.0082	0.0100	0.0075	0.0072	0.0051	0.0051	0.0051	0.0027	0.0022
2007	0.0233	0.0132	0.0085	0.0097	0.0075	0.0070	0.0052	0.0049	0.0050	0.0027	0.0023
2008	0.0230	0.0139	0.0085	0.0097	0.0073	0.0066	0.0045	0.0046	0.0051	0.0026	0.0022
2009	0.0211	0.0134	0.0083	0.0093	0.0072	0.0066	0.0044	0.0044	0.0054	0.0026	0.0021
2010	0.0210	0.0143	0.0081	0.0094	0.0068	0.0067	0.0042	0.0045	0.0050	0.0026	0.0022
2011	0.0215	0.0122	0.0081	0.0088	0.0069	0.0065	0.0041	0.0044	0.0046	0.0025	0.0022
2012	0.0206	0.0127	0.0073	0.0086	0.0069	0.0064	0.0038	0.0044	0.0046	0.0025	0.0022
2013	0.0196	0.0129	0.0082	0.0087	0.0069	0.0063	0.0038	0.0045	0.0045	0.0025	0.0022
2014	0.0198	0.0111	0.0085	0.0084	0.0069	0.0059	0.0038	0.0045	0.0044	0.0025	0.0023
2015	0.0194	0.0113	0.0080	0.0082	0.0068	0.0059	0.0039	0.0046	0.0043	0.0025	0.0023
2016	0.0191	0.0111	0.0079	0.0080	0.0067	0.0059	0.0040	0.0042	0.0041	0.0025	0.0022
2017	0.0188	0.0108	0.0078	0.0078	0.0066	0.0058	0.0039	0.0042	0.0040	0.0025	0.0022
2020	0.0174	0.0099	0.0072	0.0071	0.0063	0.0053	0.0036	0.0041	0.0035	0.0023	0.0021
2025	0.0156	0.0088	0.0064	0.0060	0.0056	0.0046	0.0033	0.0038	0.0028	0.0021	0.0020
2030	0.0140	0.0077	0.0057	0.0051	0.0049	0.0040	0.0031	0.0034	0.0023	0.0019	0.0018
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Fossil-fuel based and conventional electric equipment (e.g. electric resistance heaters and electric water heaters, either instantaneous or with a storage tank) continue to dominate the global buildings market, accounting for more than 80% globally of buildings heating equipment stock (excluding traditional use of biomass).

In recent years, condensing gas boilers, with efficiencies often higher than 90%, have gradually displaced coal, oil and conventional gas boilers, whose efficiencies are frequently less than 80%. But progress is not fast enough to meet SDS ambitions, which call for the use of high-efficiency fossil fuel equipment at the very least (e.g. condensing boiler technologies) and require a drastic shift towards clean energy technologies such as heat pumps and solar thermal heating.

Solar thermal heat capacity has increased by 250% over the last decade, and heat pump sales are increasing in many markets. In Europe, heat pump sales increased by 20% in just two years, mainly driven by growth in air-source heat pumps.

Yet despite this progress in Europe and elsewhere, significantly greater attention is needed to increase sales of high-performance heat pumps and solar thermal heating in buildings.

District heating systems continue to play a large role in meeting heating demand (especially space heating) in many parts of China, Europe and Russia. The number of new connections (approximated here as “sales”) have grown by around 3.5% a year since 2010, driven in particular by China’s extensive district heat network.

But significant effort is still needed to reduce the carbon intensity of district heating. China’s reliance on coal for district heat is increasing emissions globally, but increased policy attention to high-polluting production of district heat in the last two years promises improvements in energy and carbon intensities through greater use of industrial excess heat recovery, natural gas and clean coal technologies.

In Japan, the number of ENE-FARM hydrogen fuel cell units deployed annually remained steady, with a cumulative installation of 236 000 units at the end of March 2018. Most of these units are installed in single family homes and continue to benefit from subsidy support, which will remain until 2020.


Tracking progress

Emissions related to heating in buildings have remained roughly constant since 2010. Sales of heat pumps and solar thermal technologies for heating in buildings are growing, but this is dwarfed by sales of fossil-fuel based heating equipment.

To date, only three countries explicitly mentioned heat pumps for water heating in residential or commercial buildings in their Nationally Determined Contributions submitted as part of the Paris Agreement. Twenty-two countries, mostly in the Caribbean, the Middle East and Sub-Saharan Africa, mentioned solar energy as part of their sustainable energy actions for heating and cooling buildings.

To meet the SDS goals, the share of heat pumps and solar thermal heating needs to triple to more than one-third of new heating equipment sales by 2030. Alongside building envelope improvements, deployment of these low-carbon, high-efficiency heating technologies will help increase heating intensity improvements to around 3.3% annually in the coming decade. Improvement will be much faster in heating-intensive countries in Europe and Eurasia.

Low-carbon district heating, potentially providing greater flexibility across energy value chains, can equally support decarbonisation of heating in buildings. But the carbon intensity of district heat – which has remained constant in recent years – needs to improve by around 1% per year.

This can be achieved through a combination of low-carbon generation technologies, better management of heat demand (for instance by deploying heat meters and improving building envelopes) and greater flexibility in district energy networks (for example, allowing for input of variable renewable energy and excess heat from industry).


Innovation

One notable development in 2017 was a proposed collaborative effort by the IEA Technology Collaboration Programmes (TCPs) for Heat Pumping Technologies (HPT TCP), Energy Storage through Energy Conservation (ECES TCP) and other TCPs like District Heating and Cooling (DHC TCP). This collaboration seeks to develop a prototype “Climate Comfort Box” that would deliver high efficiencies with flexible storage at affordable prices in order to deliver on ambitions for affordable heating and cooling under Mission Innovation.

The IEA’s new Innovation Tracking Framework identifies key long-term “technology innovation gaps” across the energy mix that need to be filled in order to meet long-term clean energy transition goals. Each innovation gap highlights where R&D investment and other efforts need improvement.

Explore the technology innovation gaps identified for heating below:

Solar

Why is this RD&D challenge critical?

A key issue for space heating is inter-seasonal storage. Sun irradiance is highest during the summer when the heating demand is the lowest. Seasonal storage would allow for this energy to be used when needed.

Key RD&D focus areas over the next 5 years

Phase Change Materials (PCMs) have the ability to absorb and release energy (as latent heat) when changing between solid and liquid phases. Further improvement of these are necessary to enable the thermal energy stored to be maintained below the melting point of the original material. The idea is to be able to "release" the thermal energy when it is needed. This can potentially be used for space heating, cooking and drying of crops.

Key initiatives

The Grossman Group at MIT have made significant advances on the fundamental material's design level.

Key RD&D focus areas over the next 5 years

  • Education for planners, architects and builders on the benefits of BIST.
  • Development of absorbers/collectors with long lifetimes, easily installed and with appealing aesthetics.
  • Reduce costs - according to Maurer, Cappel and E.Kuhn, (2017) the highest potential when developing business models lies in models that do not include the traditional three-stage distribution but use synergies among the labour branches on-site.

Key initiatives

EU Horizon 2020 and Solar Heat Europe (ESTIF).

District heating

Why is this RD&D challenge critical?

  • The transition towards a low carbon electricity system requires a higher penetration of VRE.
  • Integration costs are expected to increase i.e. there is a need for improved flexibility. This can be achieved in part by coupling the heat and electricity systems as this would help balance the variability from VRE.
  • IRENA lists the following drivers for an increased share of REs; Environmental, System benefits (i.e. coupling with the electric grid and the waste sector), Synergies with the urban environment & Increased energy security.

Key RD&D focus areas over the next 5 years

The technology is mature but there are certain obstacles that need to be overcome to achieve more integrated systems:

  • Whereas power pools are composed of a number of countries, DH systems are usually national and therefore regulated by national and local rules, which may create obstacles for more integrated DHC-electric grid systems.
  • Large central power plants will run less hours in a decreasing price environment, resulting in a lack of incentives to invest in flexible capacity.
  • Due to tax exemptions for biomass local DH utilities tend to substitute gas-fired CHP plants rather than heat-only boilers.
  • Costs for distribution systems need to decrease for DHC to be competitive with decentralised generation.

Key initiatives

Flex4RES.

Why is this RD&D challenge critical?

  • Heat sources used in district systems operate more efficiently at low temperatures, particularly impacting many of the lower carbon options. This means that distribution temperatures must decrease in order to improve the technology and decarbonise district heating grids.
  • Today temperatures are around supply 86 C and return 47 C. The targets for 4GD systems are a supply temperature between 45-50 C and a return around 20 C.
  • Low temperature operation would enable utilisation of more industrial heat, geothermal and heat from cooling processes. It would further decrease heat losses in distribution networks, improve efficiency of district-size heat pumps or through flue gas condensation in condensing equipment.

Key RD&D focus areas over the next 5 years

Third pipe system Fourth Generation District Heating (4GHD-3P), apartment substations, longer thermal lengths.

Key initiatives

  • The EU launched the TEMPO programme (TEMPerature Optimisation for low Temperature District Heating) in Oct 2017 and it will run until September 2021.
  • Funded EU projects are carried out by: Smart Cities, Interreg, H2020, FP7, IEE, SAVE and FP5.
  • Other key initiatives: Halmstad University (Sweden) has accomplished distribution temperatures of 50 and 20 Celsius, and a prototype funded by TEMPO will be built.
  • 4DH initiative in Denmark.

Explore all 100+ innovation gaps across 38 key technologies and sectors here.