A Brief History of Enwave

Sept 1964

Toronto Hydro begins supplying district heating from its newly constructed steam plant at Pearl Street.

May 1968

Provincial Air Pollution Control Service approves a small expansion to Pearl Street Steam Plant and City Council authorizes the construction of a new steam plant by a consortium of hospitals at Walton Street.

Nov 1969

City Council commissions a study to chart the potential expansion of district heating in downtown Toronto.

Oct 1970

Commissioning of Walton Street Steam Plant.

May 1974

Recommendations of District Heating Study adopted by Council:

  • Integration of the six steam distribution networks operating in Toronto to be managed by a new corporation
  • Construction of a combined refuse-fired and fossil-fuel fired steam plant remote from downtown to provide base load for integrated system
  • Decommissioning of Pearl Street Steam Plant
Nov 1976

All parties agree to integration but Toronto Terminal Railways Company withdraws less than one year later.

Apr 1979

City Council authorizes $2.7 million purchase of Gulf Oil site at Cherry Street and Lakeshore Boulevard as the site for the proposed refuse-fired steam plant.

Dec 1980

Toronto District Heating Corporation Act, 1980 receives third reading in legislature.

May 1981

Metro Council approves Waste Management Master Plan which includes City of Toronto proposal for a refuse-fired steam plant.

May 1982

Canada Mortgage and Housing Corporation presents results of a study of "Freecool" described as "the concept of pumping water from the bed of Lake Ontario through a hydraulic and heat transfer system to cool major downtown buildings". Study suggests that it is "technically and financially feasible" to displace 137,000 TR of electrically generated cooling capacity in downtown Toronto. Estimated cost of project approximately $680 million.

Nov 1982

Proclamation of Toronto District Heating Corporation Act. Steam networks of hospitals, Toronto Hydro and Queen's Park are amalgamated.

Feb 1984

Transfer of assets from Toronto Hydro to TDHC completed and new company begins operating.

1985 - 1987

Queen's Park plant decommissioned and TTR plant demolished with customers from the latter system being transferred to TDHC.


Installation of new low Nox boiler at the Walton Street Plant adds 18% more capacity to system.


Enwave opens Chilled Water Plant in the Metro Toronto Convention Centre South Building.


TDHC begins supplying steam for absorption cooling; the Queen's Park Plant is re-commissioned, adding 15% capacity to system.


Environmental Assessment for the Deep Lake Water Cooling project receives approval.


International District Energy Association (IDEA) recognizes TDHC as the 1999 System of the Year.


Restructuring of TDHC completed and company is reconstituted under Ontario Business Corporations Act with Borealis Penco and City of Toronto, each owning 50% of the new company respectively.


TDHC undergoes corporate make-over and is renamed Enwave.

Phase II of DLWC design work is completed expanding existing chilled water distribution system north on York Street to Wellington Street.


Three 5 km pipes are deployed and lowered into Lake Ontario in preparation for the Deep Lake Water Cooling system.


Enwave's Deep Lake Water Cooling system is launched on August 17, 2004 at the "Cooling the Core" celebration attended by actor and environmental activist Alec Baldwin and Ontario Energy Minister Dwight Duncan.