Data centers have traditionally been seen as a consumer of energy, not a source of sustainable energy production. STACK is changing this perception in Toronto by embracing alternative fuel sources and working with provincial energy regulators in Canada. Innovation is paving the way for a sustainable demand response to regional energy needs.

Power in Ontario

 In Ontario, Canada, low-carbon electricity generation has become the norm. In fact, based on recent 2020 data, about 93% of Ontario’s electricity was produced using zero-carbon emitting sources.

 Sustainable sources of electric power in the province continues to be a national priority in Canada, with ongoing incentives and government programs aimed at rewarding the responsible generation, transmission, and consumption of electric power throughout each province.

The Industrial Conservation Initiative (ICI) is an example of one of these government programs. This demand-response program is designed to push power back into the Ontario system when it is at its highest demand. Data centers in Toronto have a distinct opportunity to participate in the ICI by utilizing their already existing, and underutilized, backup generators. For most critical capacity data centers, backup generators are consistently maintained and tested but otherwise lay dormant. By adding in a layer of innovation and sustainability, a host of these backup generators are manufactured, or retrofitted, to accept Hydrotreated Vegetable Oil (HVO) fossil-free diesel as a primary or secondary fuel source.

Why Toronto, and Why Now?

 It’s difficult to truly understand the electric power consumption landscape in Ontario without considering the greater Toronto region—where STACK is making its mark with our upcoming 8MW TOR01A data center. Sitting on 19 acres, this repurposed facility is just six miles from downtown Toronto with future plans to expand this campus to a total of 56MW of critical capacity.

Our TOR01 data center will be tied into a municipal power grid that serves all of Toronto and the surrounding area. As sophisticated and well-planned as this grid is, the regional demand for power often creates spikes in usage, much like any municipality. This demand has led to creative solutions to address on-peak power development in Toronto, including socializing the Global Adjustment program to regulate energy rates. 

Getting a Grasp on Global Adjustment

 Every month, every electric power consumer in Ontario pays the Global Adjustment charge.

This charge is levied to pay for the cost of providing adequate power supply and a wide variety of government-sponsored programs aimed at ensuring electric power is sustainably generated and consumed. Some of these programs include:

  •   Conservation Programs
  •   Refurbishing and Building New Infrastructure
  •   Energy Storage Program
  •   Industrial Electricity Incentive Program

In sum, the Global Adjustment charge makes up for the gap between the wholesale market price of electricity and regulated rates, payments for building or refurbishing infrastructure, contracted rates, and cost of delivering conservation programs. Generally speaking, when the market price is lower, the more the consumers have to pay to cover the cost for power generation.

Demand Response

Ontario has advanced emissions standards and requirements that are similar to those found in California. Meeting emissions standards is vital while engaging in what is known as demand response—or reducing or shifting electricity usage during peak periods.

In support of these emissions standards, the STACK TOR01 data center will be able to run its backup generators when the Toronto grid system demand is peaking, also resulting in an economic benefit for everyone involved. Additionally, each generator on STACK’s Toronto campus is rated to accept HVO fossil-free diesel. The use of HVO-fueled generators as part of a strategic demand response program has three categorical benefits:

  1. Running generators reduces overall demand on the grid, thereby increasing grid reliability for all consumers.
  2. Customers realize cost savings from overall lower energy rates by avoiding Global Adjustment charges.
  3. Demand response optimization is made ‘greener’ by using a generator with a fossil-free fuel type.

The Future for Generator Manufacturers 

Critical capacity and other commercial electric power consumers are starting to partner with the major commercial power generator manufacturers to test and enhance these diesel-powered machines to be more sustainable. More than ever before, there is a heightened focus to build higher-efficiency, more carbon-neutral generators that can be used to meet the needs of continuous reliable power, demand response, and, in the case of the Ontario power market, Global Adjustment Reduction programs.

With the advent of HVO as a fuel source, fossil-free optionality now exists for the traditional diesel-fueled generator technology. One example is the Caterpillar C175 (included in the basis of design at the TOR01 facility), which allows the use of HVO as a fuel source with the addition of specialized hardware.

Today, Toronto; Tomorrow, the World

How STACK is operating in Ontario has implications for our clients, the everyday Canadian, and the data center industry as a whole. Our adoption of HVO-fueled power technology can be seen as a positive use-case for the industry and forward-thinking use of electricity in markets throughout the world.


Tin Fong
Senior Director of Energy & Sustainability
Brian Medina
Director, Strategy and Development