This page presents cross‑cutting research with involvement of the IEA District Heating and Cooling Programme that goes beyond individual Annexes.

Thermal Networks: Empowering the Smart Transition to Net Zero

This flagship report, prepared by the IEA Thermal Networks Coordination Group (IEA TNCG) with 11 IEA Technology Collaboration Programmes, shows how modern district heating and cooling integrate renewables, waste heat, large heat pumps, storage and digitalisation to deliver deep decarbonisation and affordable comfort. It targets decision makers in government, utilities, industry and finance, offering clear messages on policies, planning tools and investments for a just and secure heat transition.

• ​Download: Thermal Networks: Empowering the Smart Transition to Net Zero (December 2025).

​Thermal Networks Case Studies: Impact Factsheets and Success Stories

The companion case study collection presents concise factsheets from several countries, covering solar district heating, geothermal systems, bioenergy with CCS, thermal storage, industrial surplus heat and large‑scale heat pumps. Each example summarises concept, investment, CO₂ impact and co‑benefits, providing practitioners and planners with ready‑to‑use input for projects and local heating and cooling plans.

• ​Download: Thermal Networks Case Studies: Impact Factsheets and Success Stories (December 2025).

District Heating Network Generation Definitions

This short guidance document from the IEA DHC Executive Committee offers a practical, temperature‑based definition of district heating network generations for use in communication, planning and benchmarking. It clarifies that systems previously labelled “5th generation” should be described as thermal source networks (TSNs) and treated as a subclass of 4th generation networks, and defines 1st–4th generations by carrier medium (steam vs. water) and typical supply temperature ranges.

• ​Download: IEA DHC District Heating Network Generation Definitions (February 2024).