Powering Ottawa’s future with lower-carbon design

When you flip a light switch, turn up the heat or charge your electric vehicle, you depend on Hydro Ottawa to deliver safe, reliable power. But as our city grows and the transition to clean energy accelerates, how we build the infrastructure behind that power matters just as much as delivering it.

Our first substation built using lower-carbon design

Historically, Hydro Ottawa built a new municipal transformer station roughly every five to seven years, but now we are on track to energize a new one nearly every year through 2030. That is why we are proud to introduce the new Piperville municipal transformer station (MTS)  — our first lower-carbon substation that proves we do not have to choose between meeting the city's growing energy demands or reducing our carbon footprint. We can do both.

Built to serve customers in southeast Ottawa, Piperville was designed to minimize environmental impact without compromising power quality. This state-of-the-art facility provides 90 megawatts of power, matching that of our largest existing substation, while achieving a 12.3 per cent reduction in embodied carbon emissions when measured against Cambrian MTS, our baseline reference.

What are embodied carbon emissions?

When we think about the environmental impact of major electrical infrastructure, our minds may naturally jump to the operational footprint — the greenhouse gas emissions generated from running equipment. But a substation's total carbon footprint actually stems from multiple stages across its entire lifecycle, one of which are the emissions created from the materials and physical construction processes of a new facility before it is even turned on.

This is known as embodied carbon.

For a utility company like Hydro Ottawa, embodied carbon represents the primary slice of lifecycle emissions we can directly control through our choices in engineering, design and procurement - unlike operational or downstream emissions. For this reason we specifically targeted embodied carbon when designing the Piperville station, evaluating currently available lower-carbon solutions across the areas where embodied emissions are created: the physical building, the exterior yard foundation and the power equipment.

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Piperville by the numbers
To measure the environmental performance of Piperville, Hydro Ottawa established our 2022 Cambrian MTS, which features a similar footprint and capacity, as the official baseline reference.

By making deliberate lower-carbon design choices, we eliminated approximately 618 tonnes of CO2e. Here is how those carbon savings break down:

• Building design (508 tonnes reduced): By making the main building smaller with a more compact layout and utilizing an efficient half-depth basement design, we significantly reduced the amount of raw materials needed for construction.  
   
• Station yard foundation (202 tonnes reduced): Using sustainable, lower-carbon concrete mixtures for the site's massive exterior foundation, we reduced structural emissions while safely supporting heavy electrical equipment.
   
• Power equipment (92-tonne increase successfully offset): Although procuring the required high-capacity electrical equipment, including Piperville’s two massive 230 kV transformers, resulted in a 92-tonne increase in emissions, the combined carbon savings achieved across our building and yard designs successfully offset this impact.

As new lower-carbon solutions and technologies become available, we expect to achieve progressively greater carbon reductions.  

Community benefits

While Piperville sets a new environmental benchmark, its main job is delivering the energy our community relies on every day. Here is how the new station directly benefits Ottawa residents and local businesses in southeast Ottawa:

• Enhancing grid resilience: Piperville provides increased system redundancy to mitigate the impacts of major weather events — reducing outage frequency and speeding up restoration times.
   
• Powering regional growth: The station provides the added electrical capacity required to support the region's rapid growth — powering new residential developments, local commercial expansion and major municipal transit electrification, such as Ottawa’s growing fleet of zero-emission electric buses.
   
• Future-ready grid: Designed with long-term energy needs in mind, Piperville lays the foundation to integrate clean energy innovations, including customer rooftop solar generation and battery energy storage systems, directly into our local grid.
   

A new standard for sustainable infrastructure

Piperville is not a single one-off project — it is our repeatable roadmap for the future.

As we continue to build out the distribution system to meet the growing energy needs of Ottawa and Casselman, Hydro Ottawa will develop all new municipal transformer stations as lower-carbon facilities, a commitment that is already embedded into the design and construction of our upcoming stations, including the Hydro Road and Mer-Bleue stations scheduled for 2027, as well as Greenbank and Old Second Line in 2028.

With Piperville leading the way as our very first proof of concept, this lower-carbon design marks an exciting step in our journey toward building a stronger, modernized grid that supports a clean, sustainable energy future for all of Ottawa.

Safety moment: staying safe around substations 

Hydro Ottawa operates over 80 substations across the city. These facilities contain a wide variety of high voltage electrical equipment. For your safety, never climb a substation fence or enter the property. If a ball, toy or personal item ends up inside the fenced area, leave it there and contact Hydro Ottawa at 613-738-6400. We'll send trained personnel to retrieve it for you safely.