What district energy actually is
Three parts, one idea: make the heat somewhere else, and pipe it.
Instead of every building burning its own fuel in its own basement, a district energy system makes heat (and often chilled water, and sometimes electricity) at one or more central plants and distributes it through buried pipes to many buildings. Each building gets a heat exchanger instead of a boiler.
CEEDC's working definition, the one that decides what counts in the numbers on this page: a system that supplies thermal energy for space conditioning and water heating to more than one building. Campus systems — universities, hospitals, military bases — count. Industrial heat used inside the plant gate does not, because that energy is doing something other than conditioning space and heating water.
Every district energy system has these three parts plus an operational structure for control and, where customers are billed, an administrative one. Source: CEEDC, District Energy in Canada (2023).
Fuel switching at scale. Changing one plant from gas to biomass, sewage heat or a big industrial heat pump decarbonises every connected building at once. Doing that building by building means hundreds of separate retrofits.
Things that only work big. Deep-lake cooling, sewage heat recovery and municipal waste heat are not viable for a single house. Spread across 180 buildings they are.
Nothing in the basement. No boiler, no flue, no fuel storage, no combustion inspection — floor space and maintenance handed back to the building.
Pipe is expensive. Thermal network piping runs on the order of $1,000 per foot installed. You need enough heat demand per metre of trench to pay for it, which is why district energy clusters in dense downtowns and campuses.
You have to dig. Retrofitting a network into an existing street is disruptive and slow, so most growth happens in new development or on land already under one owner.
It is a long commitment. Systems are financed over decades — CEEDC found the average commissioning year skews old, and Canada's oldest system has been running since 1880.
The generations, and why "5G" is contested
The industry counts district heating in generations. As of 2024 the IEA's own committee says one of the labels should be retired.
Generations are shorthand for how hot the water in the pipe is — and that one number drives almost everything else. Hotter networks lose more heat through the pipe wall, need more robust pipe, and can only be fed by sources hot enough to reach that temperature. Cooler networks lose less, can be built from cheaper plastic pipe, and open up sources that were previously useless: waste heat at 25 °C, a lake, a sewer.
In February 2024 the IEA's District Heating and Cooling technology programme published a deliberately simplified ladder, defined purely on network characteristics, so that the terminology means the same thing in everyone's slides. Tap a row to expand it.
Source: IEA DHC, District heating network generation definitions, February 2024, drawing on Lund et al. (2014, 2021), Sulzer et al. (2021) and Werner (2022). The committee notes plainly that a later generation is not necessarily better for climate mitigation — that depends on emissions, exergy and life-cycle cost for the specific case.
What's in the pipe, and how many pipes there are
Steam, hot water or chilled water — and whether the network bothers to bring it back.
Steam. The original carrier. Enormous heat capacity per kilogram, moves without pumping, and reaches any building temperature you like — but runs hot, leaks readily, needs licensed high-pressure operators, and loses a lot of heat to the ground. CEEDC's data shows steam systems need noticeably more staff than hot water ones, because provincial boiler and pressure-vessel rules demand closer supervision.
Hot water. The modern default. Lower temperature, lower losses, cheaper pipe, and — crucially — it can be fed by heat pumps, solar thermal and waste heat, which cannot make steam economically.
Chilled water. The cooling side. Supply is typically 4–8 °C; Canadian systems reporting it cluster tightly around 6 °C.
Single-pipe. Flow goes out and is consumed, not returned — classic steam district heating, where the condensate is sometimes dumped rather than piped back. Cheap to build, wasteful to run: you throw away both the water and the heat still in it. Only 9 Canadian systems reported their condensate return rate at all, and those ranged from 45% to 90%.
Two-pipe. Supply and return. Every modern hot-water and chilled-water network. The difference between the two temperatures — the ΔT — is what actually determines how much energy each litre delivers, which is why a low return temperature is something operators chase.
Four-pipe and ambient loops. Heating and cooling delivered simultaneously on separate pairs, or — in a thermal source network — a single uninsulated ambient loop that each building's heat pump draws from or rejects into, so one building's cooling becomes another's heating.
Fuels and equipment
What Canadian plants actually burn, pump or recover — and what the industry is buying next.
Boilers — gas, oil, biomass. Still the backbone: natural gas appears in most Canadian systems. Oil and diesel usually appear alongside gas rather than alone, because they serve as backup and peaking capacity.
Cogeneration (CHP). An engine or turbine makes electricity, and the heat that would otherwise go up the stack is captured for the network. CEEDC counts these separately; at least 82 district energy systems in the harmonised database include cogeneration.
Heat pumps. Increasingly the whole point. An industrial heat pump lifts low-grade heat — sewage, a lake, a data centre, ambient air — up to network temperature, and only works if the network temperature is low enough. This is the mechanism connecting sections 02 and 04.
Electric boilers. Simple, cheap to install, expensive to run; useful for peaking and for soaking up cheap or surplus electricity.
Thermal storage. A big insulated tank that decouples when heat is made from when it is used. Rare in Canada so far: of 31 systems asked, only 5 use it.
Free cooling. Deep lake or sea water cold enough to cool buildings directly, with no chiller — Toronto's Deep Lake Water Cooling is the flagship.
Canada by the numbers
Everything below is computed from CEEDC's public file, with the sample size on every figure — because coverage varies enormously field by field.
CEEDC's public download does not reproduce the totals in CEEDC's published report: respondent-confidential values were withheld from the public file, so file totals come out lower on a smaller n. Both are correct — they answer different questions. This page never mixes them, and never presents a file-derived total as the report's figure.
How much of this do we actually know?
The most important chart on the page, and the one nobody puts on a slide.
Every system in the inventory
All 254 district energy systems CEEDC records — operating, planned and decommissioned. Click a point or a row for the full record.
What's being built now
CEEDC's inventory closed in 2023. Two things have happened since: the systems it already listed as planned, and the ones that opened after it went to press.
How this page was built
Two versions — the short one, and the one with the field names in it.
Everything on this page comes from one national inventory, kept by the Canadian Energy and Emissions Data Centre at Simon Fraser University and paid for by Natural Resources Canada. CEEDC emails a questionnaire to district energy operators across Canada, checks the answers, and publishes both a report and a downloadable database. We used the database they publish, and their 2023 report for the figures the database doesn't contain.
Three things are worth knowing before you trust a number here.
One: most systems didn't answer. CEEDC knows about 238 operating systems. In the 2023 round, 38 of them filled in the survey — about one in five. Roughly 160 have detailed information from any year. So a chart saying "45 systems do X" is telling you about the ones that replied, not about Canada.
Two: the data isn't all from the same year. Each system's entry records the year its numbers refer to, and those run from 2014 to 2023. A third of the entries are from 2017. "The 2023 inventory" is really a decade of snapshots stacked together, which is CEEDC's own stated caveat, not a criticism.
Three: the public file is smaller than the report. Some operators' figures are confidential, so they're in CEEDC's analysis but not in the file anyone can download. That means our totals are lower than the published ones. We show both, side by side, rather than picking whichever looks better.
Where a number could not be verified, it is left blank rather than estimated. Where a system reported "no", that is shown differently from a system that simply never answered.
Source. CEEDC Innovative Energy Facilities database, district energy subset — CEEDC_IEF_district energy.xlsx (254 rows, de == True) and CEEDC_IEF_public.xlsx (3,644 rows, the full IEF superset used here only as a map context layer). Both are public downloads exposed inside CEEDC's own Tableau dashboard. Sheet layout: row 1 units, row 2 field names, row 3+ data. Dashboard last updated 2024-01-24; report published December 2023.
Status split. status ∈ {Operating (238), Planned (13), Decommissioned (3)}. Every aggregate on this page is computed over Operating only unless the chart says otherwise; the 238 matches the report's headline count exactly.
Tri-state flags. de_hs / de_hw / de_cw and every *_used fuel column are Yes / No / empty. The empties are preserved as null, not coerced to false — 99 operating systems have de_cw empty and 98 have it explicitly "No", and collapsing those would invent 99 confirmed no-cooling systems. Charts show "unreported" as its own category.
Fuel sets, not a primary fuel. The workbook has no primary-fuel column. CEEDC's dashboard derives one inside its Tableau .hyper extract, which is not published, so rather than guess at their priority order this page keeps the complete fuel set per system and reports single-fuel and multi-fuel counts separately, mirroring the report's own Table 8 structure.
IEA generation assignment. Applied to de_hw_supply only. Thresholds from IEA DHC (Feb 2024): >100 °C → 2G, >70–100 °C → 3G, ≤70 °C → 4G. Exactly 70 °C is assigned to 4G, since the 4G rule ("maximum forward flow temperature of 70 °C") is more specific than the 3G range ("between 100 °C and 70 °C") and names 70 °C as the physical DHW-disinfection threshold. 1G is never inferred from a temperature — IEA defines it by carrier (steam, independent of temperature), so the steam-network count is reported separately with its own n rather than folded into this ladder. Systems with de_hw_supply ≥ 150 °C are flagged as suspect (likely a steam temperature entered in the hot-water field) and drawn distinctly rather than dropped. Systems with supply ≤ 30 °C are flagged as thermal source networks.
Implied capacity factor = de_*_production ÷ (de_*_capacity × 8760), computed only where both are present and non-zero. Values above 100% are flagged in meta.json, not silently clipped. CEEDC's own averages run 13–20%; their stated reasons are short seasons, redundancy, planned expansion and retired-but-retained capital.
Known source quirks, all handled in the pipeline and listed in meta.json: the Metadata sheet's "Detail" column is offset from its "Field" column by 4 rows from row 60 onward (so geo_used reads as "Solid Biomass" and waste_used as "Spent Pulping Liquor" if taken at face value — the fuel labels here are the corrected mapping, cross-checked against the legend CEEDC's dashboard renders); the Metadata sheet documents an npri field the data sheet lacks and omits the operator field it has; municipality_type ships in mixed case; facility and city names carry stray double and trailing spaces.
Geometry. Province outlines are unioned from the repo's existing per-province FSA polygons (geo_json/*.json) and simplified to 0.03°. Yukon has no geo_json file, so its outline is reprojected from the national FSA file with the same inverse-Lambert used by Python/canada_boundary.py. All 254 facilities carry coordinates in the source and all fall inside Canada; none are geocoded here.
Pipeline: Python/district_energy_etl.py · Docs: docs/DISTRICT_ENERGY.md · QA counts and the file-vs-report delta: districtenergy_json/meta.json.
Sources & limitations
Inventory: Canadian Energy and Emissions Data Centre (CEEDC), Simon Fraser University — Innovative Energy Facilities database, district energy subset, via the District Energy Inventory dashboard. CEEDC is funded through government and industry sponsorship; this survey is funded primarily by CanmetENERGY-Ottawa, Natural Resources Canada.
Report: Griffin, B. (2023). District Energy in Canada. CEEDC, Simon Fraser University, prepared for CanmetENERGY-Ottawa, NRCan, December 2023.
Generation definitions: IEA DHC (2024). District heating network generation definitions, February 2024.
Building-stock context: NRCan Comprehensive Energy Use Database, 2023 — also browsable in this suite's CEUD Explorer.
What this data cannot tell you. Whether district energy saves energy or emissions relative to the alternative — CEEDC says so directly: the available survey data are insufficient for that analysis, provincial aggregates for heating and cooling supplied are hard to estimate, and many systems show energy per unit floor area above provincial averages. What the costs and benefits are. Whether there is a demand-density threshold below which it stops making sense.
What we assumed. That the 238 systems flagged Operating are currently operating, at whatever date each row's year_reported refers to. That coordinates in the source are correct — they were range-checked against Canada's bounding box but not verified individually. That the IEA's temperature thresholds can be applied to a single reported supply temperature, when a real network's forward temperature varies with outdoor conditions.
What would change the answer. A higher response rate — CEEDC is explicit that as more systems are added, the averages come down, because newly identified systems are generally smaller. Temperature data for more than 27 systems, which would turn the generation section from illustrative into representative. A refreshed survey: this inventory predates the largest district energy conversion in Canadian history, which is in section 08.