What is the community heating strategy?
The community heating strategy refers to systems that provide heating and cooling to buildings across Ottawa with minimal or no use of fossil fuels. As a result, these systems do not result in significant amounts of carbon emissions. In this Strategy, the City of Ottawa is focusing on systems that serve large buildings, clusters of buildings, and new developments.
There are low carbon heating options for smaller buildings also, and information on those can be found here on the Better Homes Ottawa website.
Why is low carbon heating important?
The City of Ottawa’s Energy Evolution Strategy proposes that just over 50% of required greenhouse gas (GHG) emissions reductions required by 2050 will need to come from changing the way that new and existing buildings are heated. The Community Heating Strategy aims to address infrastructure and utility changes that will be required to facilitate mass changes in the way that buildings and communities are heated within Ottawa. When considering these changes, it is important to consider energy efficiency opportunities as well, to ensure the energy demand of buildings and communities is as low as possible.
What is a community energy plan?
Community Energy Planning is a process that considers energy early in the land-use and infrastructure planning process and identifies opportunities to integrate local energy solutions at a building or neighbourhood-scale. The Community Energy Plan describes the early stage analysis, community energy targets and implementation plan for achieving these targets. As part of the High Performance Development Standard Community Energy Plans will be required for Draft Plan of Subdivision applications, and new local plans. This process supports new communities or areas undergoing significant redevelopment in planning for low carbon community building heating solutions.
Geothermal energy refers to energy in the form of heat found underneath the Earth’s surface. Geothermal energy can be used to heat and cool smaller buildings, like homes (often referred to as geo-exchange) or to provide heating and cooling for larger communities. Geothermal systems deploy heat pump technology to exchange heat to and from the ground, produces almost no greenhouse gas emissions in the process.
In 2021, the City of Ottawa contracted a study of the open-loop geothermal resource potential within Ottawa. It is important to note that this study only looked at open-loop geothermal resource potential. Most areas in Ottawa have a strong closed-loop geothermal resource potential. This interactive map shows the open-loop geothermal resource potential within Ottawa.
Wastewater Energy Transfer (WET)
Wastewater Energy Transfer (WET) refers to the capture and use of heat found within sewer systems. Using heat exchanger technology, energy can be drawn from wastewater to provide low carbon heating and cooling solutions for individual buildings, new developments, and even whole communities.
An example of a WET system was deployed in Vancouver, through the False Creek Neighbourhood Energy Utility. This system captures heat from the wastewater from showers, dishwashers and other sources and recycles it back into the buildings.
In 2021, the City of Ottawa undertook a study to explore the potential for wastewater energy transfer systems in Ottawa. The study examined various options for WET technologies and their respective opportunities for deployment within the City of Ottawa.
The interactive map below shows the sewer lines in the City of Ottawa with sufficient flow rates to potentially support commercial scale wastewater energy transfer systems (that which is defined as Technology 3 in the study).
Technologies 1 and 2 can be deployed in more locations because they can use lower flow rates. The City of Ottawa has historical measured flow data for some locations. The City also has flow data sensors that can be deployed upon request for a fee. To submit a request for historic flow data or to deploy flow measuring technologies in a specific location, please email: firstname.lastname@example.org
Some enterprises produce waste heat which if captured can be used for building heating. These opportunities are typically unique but may prove to be highly feasible.
An example is the use of waste heat from the Kruger Paper mill in Gatineau being used to heat the Zibi development at Chaudière Falls. Although waste heat sources can be lucrative, care should be taken to ensure that prospective sources of waste heat will continue to be available over the long term.
Low Carbon District Energy
District energy systems distribute thermal energy to multiple buildings in an area or neighbourhood. Low carbon systems do so by utilizing energy sources which produce low or no greenhouse gas emissions.
These systems typically consist of a heating and cooling centre and a network of thermal pipes connected to a group of buildings. The source of thermal energy can be from a variety of sources. In order to be low carbon, it is expected that either geothermal or WET technologies will be the most common sources.
Low carbon district energy systems are beneficial for several reasons, including:
- They can enable solutions that may not be economical on smaller scale
- One system can be used to replace many individual gas appliances
- They can enable capturing surplus/waste heat from one building to be shared with another
Experience in North American cities suggest that district energy becomes feasible when roughly 1,000,000 square feet of building space is seeking heating and cooling. This is subject to analysis of heating and cooling loads and the architecture of the area seeking an energy system. Typically, district energy systems benefit from economies of scale and being able to exchange energy between locations which need heating or cooling at different times.
Relating this to the community level, district energy systems have good potential to support sustainable thermal supply by growing beyond the area where they are initially established to service existing buildings which are currently employing a combustion-based heating system.
Ottawa has several District Energy System in place and under development today, although not all of them are low carbon. Newer systems are often planned as low carbon from the outset, while older systems require upgrades to transition to low carbon heating fuels. Examples of district energy systems can be found below.
Federal District System
This system, which has been operational since 1918, serves areas of downtown and Tunney's Pasture, primarily serving Federal Government buildings, including the Parliament Buildings. The system provides heat for 80 buildings, and cooling for 67 buildings. The original system is powered by fossil natural gas.
Significant plans are underway to transition to low carbon by 2030. More details can be found on the National Capital District Energy website.
The Zibi Community Utility District Energy System – an equal partnership between Hydro Ottawa and Zibi – currently provides net-zero carbon heating and cooling for all Zibi tenants, residents and visitors in the 34-acre riverfront city. Low-grade waste industrial heat is recovered from the neighbouring Kruger tissue mill and injected into the system. In summer, heat is rejected directly or via chillers into the Ottawa River to efficiently produce chilled water to cool the buildings. The plant, which came online in December 2021, currently services three residential buildings and three office buildings totalling 615,00 square feet.
Carleton University’s buildings are served by a district energy system, using steam generated at a central heating plant. The central heating plant is powered by fossil natural gas. In 2018, the process to install a 4.6-megawatt cogeneration system began, with the aim of providing both heat and electricity to the campus.
Carleton University’s Energy Master Plan outlines the institution’s plans to achieve carbon neutrality by 2050, as electric boilers will provide low temperature hot water to buildings across the campus.
University of Ottawa
The University of Ottawa’s downtown campus is served by a district heating and cooling loop. The University aims to be a carbon neutral campus by 2040.