Biodigestors in Ontario: Addressing Economic and Logistic Challenges
North London Anaerobic Digestion (AD) facility treats source segregated food waste from local authorities and commercial waste producers. Food waste is depackaged, macerated and then digested anaerobically in large sealed tanks. CC4.0
An Article by Nettie Wallace and Ushnik Mukherjee
Imagine turning manure and food waste into renewable energy and nutrient-rich fertilizer. This is the promise of biodigesters, a technology that has the potential to transform waste management, reduce emissions, and provide alternatives to mineral fertilizers that are both environmentally and economically sustainable. Despite their incredible potential, the widespread adoption of biodigesters, especially on farms, is hampered by economic and logistical hurdles. In the SOLUTIONSCAPES project, researchers are investigating how we can overcome these challenges to harness the full benefits of this technology for Ontario.
Biodigesters offer a multifaceted solution by turning manure and food waste into biogas and digestate. The biogas can be used as a renewable energy source, while the digestate can replace mineral fertilizers, reducing environmental impacts. This technology could significantly contribute to climate-smart agriculture by managing waste more sustainably and improving soil health.
However, setting up a biodigester requires a substantial initial investment, which is often prohibitive for small to medium-sized farms. Typically, a farm needs a minimum of 3,000 cows to justify the cost of building and maintaining an anaerobic digester. This economic barrier means that only larger farms, or those that can co-digest high energy yield organics like food waste, can afford to install and operate biodigesters.
Federal and provincial/state-level low carbon and renewable fuel standard programs provide subsidies to promote biodigester adoption. However, these incentives primarily benefit larger farms with a consistent supply of feedstock. Smaller farms, despite having the potential to contribute significantly to waste management and renewable energy production, are often left out due to the scale of investment required. While the economics of larger biodigesters are more attractive, there is a need for a holistic policy that encourages the uptake of such systems while considering social, environmental, and economic factors.
In the SOLUTIONSCAPES project, we are assessing the trade-offs between social, environmental, and economic priorities. For example, we are considering the impact of biodigesters on air quality from increased transport of feedstock and flaring onsite. We are exploring whether there be nutrient leaching that would affect water quality, and how much greenhouse gas emissions will be produced. This analysis will help us optimize the spatial distribution of biodigesters across the landscape.
Biodigesters hold great promise for managing farm and food waste sustainably, but their widespread adoption is currently hindered by economic and logistical barriers. Our study hopes to understand whether changes to local infrastructure and the policy framework could unlock the potential of biodigesters for farms of all sizes. The future of waste management in agriculture lies in creating integrated solutions that address the diverse needs of the farming community and the environment.