Back to Homepage

6938

Renewable natural gas – A valuable asset in the fight against GHGs

April 25, 2022    4 min.

What is RNG?

Renewable natural gas is a 100% renewable natural gas that helps reduce greenhouse gas emissions (GHGs) in two ways: first by replacing a fossil energy by a renewable energy, then by avoiding the methane emissions from landfilled organic residual waste

 

Advantages of renewable natural gas in a decarbonization context

With the expected rise in the price of carbon in the medium to long term, the implementation of a decarbonization strategy, combined with energy efficiency and RNG, will enable Énergir customers to considerably reduce their carbon footprint from consuming natural gas.

The increased injection of RNG for consumption in Québec is a key initiative of Énergir, since RNG has many advantages:

  • For customers, RNG is a form of renewable energy that improves the supply of low carbon energy and helps them reduce their GHG emissions without needing to invest in new equipment.
  • For society, RNG permits decarbonization at a competitiveAccording to RNG prices foreseen by Énergir during this period, based on Énergir’s RNG supply contracts up to 2030. social cost for several market segments compared with other renewable energies. Also, the RNG sector helps to recover organic waste and to capture and reduce GHG emissions from several other sectors (especially municipal and agricultural), when seen from a circular economy perspective. RNG is also a new renewable energy produced locally that encourages regional economic development.

Why resort to a life cycle analysis?

The life cycle of fossil natural gas and renewable natural gas raises several questions and concerns among our stakeholders, customers and investors.

To better understand and better control its supply chain, Énergir asked the International Reference Center for the Life Cycle of Products, Processes and Services (CIRAIG) to produce an environmental profile of the natural gas distributed in Québec, based on a life cycle approach.

This study covers:

  1. the environmental impacts of our supply chain (and, more specifically, the impact of GHG emissions);
  2. a comparison of the environmental impacts (and, more specifically, the GHG emissions) of our supply chain with those of petroleum products for various uses;
  3. the reduction potential of the environmental impacts of our supply chain (and, more specifically, the GHG emissions) by a change in supply practices.

A life cycle study is therefore a useful tool in environmental decision-making that can take into account all the steps in the life cycle of a product or service.

 

What is a life cycle analysis?

It is analysis that helps quantify the potential environmental impacts associated with the life cycle of a product.

Life cycle, RNG, analysis

 

The life cycle of renewable natural gas

The lifecycle of renewable natural gas mainly depends on the source of the residual organic wastes that are the inputs in its production process.

  • CIRAIG has studied the climate impacts from the production of RNG from animal manure, wastewater, landfill sites and residual organic wastes.
  • RNG has several environmental advantages:
    • At the production stage: The production of RNG helps recover the biogenic methane emissions generated during the usual activities in the sectors where the organic wastes originate, since they serve as inputs to the biomethanization process. The production of RNG, for example, helps:​
        • capture and recover the biogas produced by landfill sites;
        • avoid the production of chemical fertilizers that emit fossil CO2 by the substitution of digestat, a by-product of the biomethanization process;
        • avoid the biogenic methane emissions emanating from the usual management of animal manure and wastewater.

      In other words, one of the advantages of RNG production is its ability to avoid releasing biogenic methane into the atmosphere. That methane is the source of energy that is captured and converted into RNG!

    • At the combustion stage: The CO2 emissions generated by the combustion of RNG are considered biogenic emissions by the experts on the Intergovernmental Panel on Climate Change (IPCCC) and thus do not contribute to climate change.

RNG: Potentially carbon neutral, even carbon negative

While RNG is a renewable source of energy, just like the hydroelectricity produced in Québec, its production and distribution produce GHG emissions.

On the other hand, as the CIRAIG analysis shows, the sources of RNG are not all equivalent when it comes to reducing GHG emissions over the whole life cycle. However, the activity sectors where the organic wastes originate (agriculture, municipalities, sludge from water treatment) may generate significant GHG reductions. Depending on the source of RNG, the GHG emissions avoided may be higher than the emissions generated and, consequently, the RNG may be carbon neutral, even carbon negative. RNG produced from animal manure is able to generate the most significant reduction in the carbon footprint.

Advantages of renewable natural gas in a decarbonization context

Three major conclusions can be drawn from the CIRAIG analysis:

  • Over its entire life cycle, RNG can generate considerable emission reductions and encourage local production, when seen from a circular economy perspective.
  • The distribution of RNG thus helps reduce the carbon footprint of Énergir’s supply chain.
  • Of all the energies studied by CIRAIG, the possibility that RNG is carbon negative makes it the one that can generate the greatest reductions in GHGs – including hydroelectricity!

Increased availability to fight climate change

Against a backdrop of the global approach to decarbonization, RNG represents an excellent way to reduce GHG emissions, in concert with other initiatives such improving energy efficiency, for example. That is why Énergir is continuing to invest in this sector and to increase the volume of RNG in its network. Customers can now have access to RNG if they so wish and thereby contribute to meeting their own GHG reduction targets. In time, that is, by 2030, Énergir aims to have RNG represent at least 10% of its annual volume delivered for consumption, which is equivalent to an annual reduction in emissions of one million tonnes eq. CO2.

 

Philippe Lanthier
Practice Leader, Climate Change

Continue reading