Yale Carden, M.AIRAH

GeoExchange Australia / University of Wollongong
The evolution of district thermal energy systems and their role in the transition to a net zero built environment

Renewable thermal energy is the demand side equivalent of renewable electrical energy. In terms of their evolution, both forms of energy are mostly on parallel paths. They both have the objective of reducing emissions, they both experience lower demand on a per unit basis, they both look to use local and renewable sources of energy, and they both utilise tools such as storage and digitalisation.

The one area where these otherwise parallel paths diverge is with decentralisation and centralisation. Renewable electrical energy, in the form of rooftop solar, is an almost perfect example of decentralising the supply of electrical energy. In the thermal energy sector, centralisation in the form of district heating and cooling is trending as the benefits of sharing and diversifying thermal energy across heating and cooling options are realised. Enhanced accessibility, both technically and financially, is also a feature.

This presentation will explore the evolution of centralised thermal energy systems, from first-generation high temperature district heating systems, to fifth-generation systems that utilise lower temperatures and provide both heating and cooling. Such fifth-generation systems offer an integration of renewable electrical energy (supply) and renewable thermal energy (demand) such that decarbonisation and electrification feature as part of the transition towards a net zero built environment.

Yale Carden is the Founder and Managing Director of GeoExchange Australia and an Honorary Fellow with the Sustainable Buildings Research Centre (SBRC) at the University of Wollongong. He has 25 years of experience in the sustainability sector, the past 15 of which have been specifically in renewable thermal energy and heat pump systems. In his commercial and academic work he advises the public and private sector across the Asia Pacific and South America.

Yale was recently engaged by GNS to conduct a preliminary feasibility study for a district thermal energy system for the proposed Taupo East Development in Taupo, New Zealand. This work forms the basis of this presentation.