Design of consumer thermal substations for the integration of distributed solar technologies in District Heating systems

Victor Sanchez and Roberto Garay of Tecnalia presented a new consumer substation at the 5th International Solar District Heating Conference. This concept of substation for the connection of Solar Thermal into District Heating networks will be developed within the RELaTED project.

Abstract

In most cases, building service designers choose between Solar thermal (ST) and District Heating (DH) technologies for their integration in buildings. By doing so, only a fraction of the buildings within a particular district is used for ST, while at the same time energy intensity in DH networks can be reduced. In some cases, building-integrated solar thermal systems are connected to DH networks by means of dedicated pipes. In all these cases, sub-optimal situations are reached with a lower fraction of renewable heat, reduced network strength and/or additional heat losses.

In this paper, a consumer substation concept is proposed with reversible heat flow and net metering, which avoids local thermal storage in the solar loop. Adaptations required for multi-dwelling buildings are presented.