Back to Homepage


Natural gas emergency generators: A reliable and safe alternative


May 27, 2024    4 min.

Power outages, natural disasters, fires, business continuity, etc.—the usefulness of emergency generators is well established, and severe weather events in recent years have only highlighted how important they can be. As of 2016, emergency generators can be powered by natural gas from a distribution system. Natural gas is therefore a reliable alternative fuel for which no on-site tank is required. In this article, we’ll provide an overview of the key steps involved in installing this type of equipment according to best practices and standards.

What is an emergency generator?

An emergency generator is a machine that ensures essential functions such as property protection, firefighting and building evacuation. It is used to power devices such as:

  • fire pumps
  • emergency elevators
  • emergency lighting
  • alarms and alarm panels

There are also backup generators that provide backup power to equipment and processes that are not essential to the safety of building users. For this type of generator, the regulatory requirements are less stringent since their use is not directly related to public safety. For example, a generator is considered either emergency or backup, depending on how it is used. It is therefore important to clearly define generator use, to ensure that applicable legal obligations are met.

Regulatory framework

The installation of a generator requires a multidisciplinary team working to several codes and standards. The first step in the process is to identify the main use of the building under Article 3.1.2 of the National Building Code. After this crucial step, articles 3.2.6 and 3.2.7 define the applicability of the gas as an energy source. Depending on the type of plant and application, the following three codes may apply:

  • CSA Code B149.1-20: “Natural Gas and Propane Installation Code.”1
  • CSA Code C282-19: “Emergency Building Power Supply”2 (reference in French).
  • CSA Code Z32-21: “Electrical safety and essential electrical systems in health care facilities.”3

CSA Code B149.1 outlines the general requirements for the installation of natural gas and propane equipment. For emergency generators, the piping leading to the emergency generator must be independent of any other equipment, be equipped with a manual shutoff valve and not be equipped with an overpressure shutoff device. The idea here is to be able to stop all equipment in the event of a fire without interrupting the natural gas supply to the emergency generator.

CSA Code C282 sets out the requirements for equipment designed to supply electrical power. The code states that emergency generators must be capable of being powered from a utility grid, without a two-hour reserve of fuel on site, provided that the reliability of the power supply can be demonstrated to the RBQ4 (reference in French).

It is important to note that a different code applies to B2 facilities, hence the importance of determining the category of the establishment as defined in the Québec Construction Code. In this case, code CSA Z32 applies.

Clear benchmarks

In this notice, the RBQ states that regardless of the fuel source, zero risk does not exist and that reliability is not just a matter of numbers, but a set of concerted actions that will optimize gas availability and safety for beneficiaries in an emergency. In addition, the RBQ does not want to receive individual applications for each natural gas emergency generator to be installed. In its July 2016 notice, the RBQ provided guidance to improve the safety of such an approach and required Énergir and impacted Énergir customers and their design engineers to follow certain requirements and processes for the installation of natural gas emergency generators. This approach is based on the fact that natural gas distribution companies in Québec rigorously apply sound management, maintenance and implementation practices for the gas distribution system. However, in order to install a natural gas emergency generator, the RBQ has put in place a few additional obligations specific to natural gas distributors:

Obligations for natural gas distributors

In order to ensure reliability, in addition to meeting “grid” standards, Énergir must:

  • Ensure that its distribution is independent of the hazards of the electrical distribution grid.
  • Ensure that natural gas used to power an emergency generator meets the quality criteria for distribution.
  • Maintain an inventory of emergency generators that rely on its network. This inventory could be used as a decision-making tool in an emergency, as needed.
  • Maintains statistics on the reliability index of its global system and by main region5 (reference in French).
  • Check that the grid segment and the metering/regulator assemblies are compatible with the addition of the emergency generator.
  • For each successful application, issue a customized letter to inform the applicant of the reliability of its network for the applicable region.

Obligations for the customer, their design engineer and their contractors

A customer can ask their design engineer to verify whether a natural gas emergency generator can be installed. Here are the steps to follow:

  1. Consult the natural gas integration guide (French only), emergency generator section for complete installation details.
  2. Submit an application to Énergir using the specially designed form. This form may be obtained from an Énergir representative.
  3. Ensure that Énergir sends the reliability letter, signed by an engineer.
  4. Check with the municipal fire department for any additional requirements.
  5. Take the necessary steps to ensure that the emergency generator meets the code requirements:
    1. Properly identified supply line from the outside
    2. Exterior location near the service line, designed to make it easy to identify the valves used to stop other equipment
    3. Gas line supplying the generator rated for two hours of fire resistance
    4. Valve-opening sensor switches (capable of switching off the gas supply to the generator) provided and connected in a way that triggers an alarm
  6. Indicate in the Emergency Response Plan (ERP) the map of the pipes supplying an emergency generator with natural gas and the location of the valve installed on the generator.
  7. The customer or building manager will need to keep a copy of the letters and correspondence on the subject in the event of consultation.
Diagram of a typical layout


Consult the natural gas integration guide for buildings (French only), emergency generator section, now. Find out about the requirements and procedures for installation and use.


With an average reliability index of 99.99988%, Énergir’s system provides a reassuring and extremely safe alternative for customers who want a backup generator without having to manage a propane or diesel tank on site. The growing popularity of natural gas emergency generators is a sure sign that they are beneficial for users. However, it is essential to regularly verify that installation complies with the requirements we’ve set out above, to ensure the safety of people and property in an emergency. If you have any questions or are considering installing a natural gas emergency generator, consult the natural gas integration guide (French only), emergency generator section, available in the Engineers section under the Tools and resources tab, or get in touch with us at with your customer’s Énergir representative.

André-Olivier Piché.
Senior Advisor, Energy expertise

Philippe Deveaux.
Assistant Advisor, Energy Expertise


Continue reading