Optimizing waste-heat recovery in Surrey’s district energy system

The city-owned district energy system Surrey City Energy provides energy for heating and hot water to buildings in Surrey’s growing city centre. Since 2015, the system has grown each year, reaching its current customer base of about 284,790 square metres of connected building floor area in 2020. This is forecast to grow to about 1.52 million square meters by 2030 to serve over 60,000 residents. The system uses low-carbon energy sources, including geothermal energy from Surrey City Hall and renewable natural gas.

The purpose of this initiative is to study the opportunity for Surrey City Energy to integrate cooling services or waste-heat recovery into buildings connected to the district energy network. Currently, buildings that operate cooling systems employ chiller-cooling tower systems and release waste heat into the atmosphere. Most of this low-grade waste heat is not being fully utilized when it could be redirected and optimized in the network to either provide heat to neighbouring buildings or offset fuel requirements for boiler systems.

The study will evaluate the potential energy recovered from specific building archetypes, assess technical constraints of heat recovery integration with the district energy system, and provide recommendations on ownership models to inform Surrey City Energy’s financial and capital planning and rate structures for its customers.

Innovative aspect(s):

• This project will foster innovation between building designers and district energy engineers during the design, installation and operation of heat recovery equipment in a manner that is compatible with the technical constraints (e.g., temperatures, flows and energy outputs) of the district energy system
• Similar technology with superior energy performance is common in regions like Japan and Europe, but B.C. currently lacks local supply and industry capacity; this study will lead to opportunities to transform the B.C. market for energy efficiency and lead the way to net-zero buildings

Replicability:

The results of this study will be shared with a working group of local municipalities that operate district energy systems and are challenged with similar issues in addressing the need for cooling in response to hotter temperatures and meeting renewable-energy targets in cost-competitive ways. The project will help inform changes to policies and technologies while spurring innovative partnerships between building designers and district energy providers.