As part of Westhills’ overall strategy to achieve the goals of a sustainable, green community, SSL was formed to become a leader in the provision of heating and cooling through an innovative Community Energy System (CES).
Community Energy System
“District Energy” is defined as the centralized production of heating and/or cooling for a wider community. The concept has been around for a long time – over 100 years – with most district energy systems operating in high-density urban areas, like downtown cores, university campuses and industrial parks. These systems have traditionally used fossil fuels (e.g. natural gas) as a central energy source.
Technically speaking, the Westhills Community Energy System (CES) is also a district energy system. It services a residential community of primarily single-family homes, which is unique in this part of the world.
The CES uses a local, renewable GeoExchange energy source to provide over 1,500 people with the energy needed for space heating, cooling and hot water*.
Users connected to the CES have less reliance on conventional energy sources, thereby reducing their carbon footprint and supporting a system which is designed, built, owned and operated by local groups.
The Community Energy System can be broken into 3 main components:
- Energy sources providing heating and cooling capacity for the system.
- Distribution of thermal energy between energy sources and energy users.
- End use of thermal energy by community members for heating, cooling and hot water*.
1. Energy Sources
Constructed in 2008-09, the primary energy source for the CES is a GeoExchange bore field located underneath Goudy Field. This closed loop system consists of over 200 vertical wells, each drilled more than 400 feet deep.
After construction, a new playing field was built on top of the energy system and turned over to the community. The underground GeoExchange infrastructure does not require maintenance and will last for many decades.
The newly constructed Westhills Arena also forms part of the Community Energy System. In order to make ice, heat is removed from the arena to cool down the surface of the floor. This energy, which would normally be expelled to the atmosphere from the building as “waste heat,” is captured and injected into the CES so it can be used again by the community.
This system was built in partnership with the City of Langford and demonstrates the ability of the CES to harness multiple energy sources.
2. Energy Distribution
After thermal energy is extracted from the bore field by a central pump station, clean heat is transferred into a water-based distribution network. Each street in Westhills contains a pair of energy distribution mains, connecting all users to a common loop (similar to a water system).
Water is used to deliver heat to and from end users (homes, townhomes, condo) because of its unique ability to store heat. The water in our energy system is only used as a vehicle to deliver thermal energy; the water itself is not actually consumed by end users and is physically separate from the community drinking water system.
The distribution network consists of 2 mains in every street: a “warm” pipe and a “cool” pipe. The warm pipe contains water running at a higher temperature and is the main energy source for heating and hot water*. The cool pipe runs at a lower temperature and acts as a cooling sink to remove heat from each home.
3. Energy for the Community
Each home connects to the warm and cool distribution mains through a ground-source heat pump (sometimes called a water-source heat pump, or GeoExchange heat pump). The mains in the street act as the supply and return loops to each mechanical system. The heat pumps convert the energy of the CES into heating, cooling or even hot water* for their home.