Thermal Energy Storage (TES) for building heating (excluding TABS)

What is thermal energy storage for heating?

Thermal energy storage (TES) is a system that stores heat for later use in building heating. This service falls under the Heating domain within the Smart Readiness Indicator (SRI), the European measurement tool that shows how well a building is prepared for smart technology.

The service concerns storage separate from thermally active building elements (TABS), such as floor heating that serves as storage mass. It refers to dedicated storage devices, for example a hot water tank or a buffer tank linked to the heating system.

What functionality levels exist?

The SRI methodology defines four levels for this service, numbered 0 to 3. Each level represents a higher degree of control and adaptability of the storage system.

• Level 0: continuous storage operation, without time or demand control.
• Level 1: time-controlled storage operation, for example based on a fixed daily schedule.
• Level 2: storage operation based on load forecasting, where the system anticipates expected heat demand.
• Level 3: heat storage suitable for flexible control via grid signals, such as demand-side management (DSM).

A higher level means the storage system can better respond to external signals, such as price or load signals from the electricity grid.

How does this service count toward the SRI score?

This service is part of method B, the extended assessment method of the SRI with 54 smart-ready services. Method A, the simplified variant with 27 services, does not include this specific service.

The functionality level of this service contributes to the score on seven impact criteria, including energy efficiency and flexibility for the electricity grid. Each criterion counts via a fixed weighting factor within the Heating domain.

A building's final score is expressed as a percentage and assigned to one of seven classes, from below 20 percent to 90 to 100 percent.