Toronto Enwave District Energy System
Within Canada, district energy systems are already being utilized for heating and cooling in various cities across the country including Vancouver, BC and Toronto, ON. The Toronto Enwave system consists of three steam-generating plants and one cooling plant which are connected to approximately 40 kilometres of pipe buried underneath the city. The original heating system was developed in the 1970s and now relies on efficient natural gas-fired boilers to produce steam. Much of this steam is used in the northern part of the system for customer heating before being returned to the steam plant in the form of condensate (warm water). This system is reliable while providing rate stability and environmental benefits, including less pollution and greenhouse gas emissions.
In 2004, Enwave added a deep-lake water cooling system to provide customers with an alternative way to cool their homes and offices. The system works by taking cold water from deep beneath the surface of Lake Ontario and pumping it through the St. John’s Pumping Station. At the Station, the cold lake water is pumped through a heat exchanger so the energy from the cold lake water chills another closed loop of water. The chilled water is then distributed throughout the network of pipes to cool buildings. Rather than pump the lake water back into the lake, it is sent to wastewater treatment plants where it is cleaned and redistributed as potable drinking water. Compared to conventional air conditioning, the deep-lake water cooling system reduces electricity use and emissions normally associated with traditional heating and cooling systems. Overall, the cooling system is a clean, renewable and reliable way to cool buildings.
Enwave, Facilities, 2013. At http://enwavetoronto.com/facilities.html
Enwave, Histories, 2013. At http://enwavetoronto.com/history.html
Enwave, Deep lake water cooling, 2013. At http://enwavetoronto.com/district_cooling_system.html