KIEHU project

Duration: 1 January 2026 – 31 December 2027
Funding: Metropolia: €58 517 (30%) , EU and state funding €136 541 (70%)
Total budget: €195 058
Partners: Metropolia University of Applied Sciences (Coordinator) and Aalto University
Parallel project: ReHeat – Regenerating Local Waste Heat for Sustainable Growth and Business

Purpose of the KIEHU Project

KIEHU develops technically and economically viable solutions for using circular economy materials from the construction and infrastructure sectors as local heat storage. By turning demolition and side streams (e.g. concrete‑based materials and biochar) into heat storages, the project supports the green transition, improves energy efficiency and reduces emissions.

Why This Project Is Needed

Building heating uses around a quarter of Finland’s total energy. At the same time, heating costs and price volatility have increased, creating cost pressure and risk of energy poverty for many property owners. Regional heat storage is still rare, even though it could cut peak demand and reduce reliance on fossil peak‑load plants.

In parallel, construction and infrastructure produce substantial material flows that are not fully utilised. KIEHU brings these two needs together: it develops heat storage solutions that use circular construction materials and support demand response in renewable energy systems.

Objectives

KIEHU’s main objective is to accelerate the green energy transition and circular economy by creating new heat storage concepts and business models in two types of urban areas:

1. A new residential area at the edge of a district heating network
2. An existing apartment building area in the heating network

Key goals are to:

• identify suitable circular materials for short‑ and long‑term heat storage and assess their potential in local energy systems
• develop analysis methods and simulations to support investments and business decisions
• create concrete, profitable and emission‑reducing circular economy models
• build business platforms and pilot new energy partnerships, energy communities and waste‑heat‑based services
• strengthen cooperation and knowledge sharing between SMEs, housing companies, energy actors, construction and demolition firms, circular economy companies, cities and RDI organisations.

Target Groups

The project targets:

• demolition, design and building‑reuse companies and other construction sector firms
• property owners (municipal SMEs, municipalities, public sector actors)
• companies building fixed or mobile heat storages
• micro and SMEs that produce or utilise waste heat (e.g. retail, bakeries, laundries, data centres, heat pump and HVAC firms, energy optimisation companies)
• housing companies and property management firms.

Impact and Added Value

In the Helsinki region, many buildings rely on district heating and face rapidly rising energy costs. Large‑scale heat storages are being built by major energy companies, but small, local storages are still missing—despite the availability of local waste heat and circular materials.

KIEHU creates:

• practical concepts for local, circular material‑based heat storages
• decision‑support tools for cities, housing companies, energy companies and SMEs
• new business opportunities and value chains around heat storage and waste heat use.

The project directly supports climate targets and the green transition by enabling low‑carbon, circular and more resilient local energy systems.