From Organic Waste to Biogas
How greenhouses help make renewable energy more sustainable
June 2, 2023 By Tom Ferencevic
What Is the status of the industry?
Fifteen years after the Ontario government first announced incentives for renewable energy, Canada still counts fewer than 300 biogas plants. If wastewater treatment plants are excluded from this statistic, fewer than 100 facilities are in operation. Though incentive programs have come and gone, biogas simply hasn’t lived up to its supposed potential. This is not from lack of effort on the part of technology providers, all of whom have their roots in successful European companies. So, how can we explain this failure, and how can we transform it into becoming a thriving industry?
What is biogas? What are the benefits?
Biogas is the fuel produced from the natural decomposition of organic matter. It is composed of 60 per cent biomethane, a very potent greenhouse gas when released into the atmosphere. But if this decomposition occurs in a closed vessel and the biogas is captured, it can be used as a natural fuel source. By using various methods, the biogas can be separated from other gases to make renewable natural gas fit for the natural gas pipeline or for use in natural gas-powered vehicles. Alternatively, the gas can be passed through a CHP (combined heat and power generator) to make electricity.
There are many benefits of biogas: it recovers organic waste and makes the most of our resources, fights climate change, supports local economies through energy production and job creation, and returns nutrients and organic matter to the land. Also, compared to other renewable energy sources, biogas can be seen as a baseload producer, since facilities run consistently 24 hours a day, seven days a week. This offsets the variability of wind and solar, which produce inconsistently or periodically.
A successful project
The key elements required for a successful biogas project include having appropriately zoned land, permitting for the receiving and handling of various types of organic waste (agricultural or non-agricultural), permitting for renewable energy production, feedstock availability, and access to the electrical or natural gas grid. Biogas facilities also require skilled operators. Even though a good design will reduce the amount of work an operator has to do, the job still needs their full attention. Therefore, considering staffing costs in the economic model can help ensure a project’s success.
While having land, proper permitting, and access to the energy grid are factors that can be met fairly easily by most farms and greenhouse operations, securing adequate and appropriate feedstock can be more of a challenge.
Dairy farms have the advantage of producing manure, which then serves as feedstock. Food waste produces more energy per tonne than manure and also generates revenue from tipping fees, but comes with its own set of biological and operational challenges. Despite sources claiming more than 35.5 million tonnes of food are wasted in Canada yearly, this food is only sometimes available in biogas facilities. Unless food is de-packaged or source-separated, the contamination with non-digestible materials makes it impossible to place in a digester. Also, most food waste occurs in urban centres, while the majority of biogas operations are located at a distance from large cities, meaning trucking costs have to be factored into the business case. Additionally, since biogas facilities operate 24 hours a day, seven days a week, having reliable, long-term contracts delivering consistent waste is essential to a successful operation.
From a sustainability standpoint, greenhouse operations stand to benefit a great deal from biogas. In addition, as hefty energy consumers, the appeal of generating electricity or natural gas on-site has tremendous appeal.
Biogas produced in an anaerobic digester is used in one of two ways: to power a combined heat and power generator (CHP) and convert the gas to electricity or to be cleaned and converted to renewable natural gas (RNG).
The advantage of a CHP is that excess heat can be recovered from the engine and directed to the greenhouse to reduce heating costs. The difficulty is that the CHP produces mostly electricity and smaller quantities of heat, which doesn’t match up with a greenhouse’s requirements primarily for heat and, to a lesser extent, light. Biogas plants don’t produce enough heat for large greenhouses (over 10 acres), but they can help small- to medium-sized greenhouses.
Regarding RNG production, biogas upgrading units are twice the cost of CHP units, making the business case more difficult. But rates are in flux, and the general trend for renewable natural gas rates seems to be rising. Effectively, large-scale deployment of biogas in greenhouse operations has not materialized because the energy produced needs to offset more of their own energy use. Therefore, the investment cost is not justified, nor is the complexity of adding on what is effectively a separate business.
The patchwork of rules and regulations
The main thing that is missing to make biogas technologies profitable for the greenhouse sector is incentives from the government. Existing programs are frequently revoked with changes in government. This lack of commitment to the cause of climate change has resulted in a patchwork of rules and regulations that do not adequately support the renewable energy industry.
Recently, the Ontario government reduced the barrier to environmental permitting for farms to receive off-farm organic waste in quantities relative to the manure they produce. This barrier reduction favours the building of biogas plants in dairy operations. On the other hand, the federal government has been offering grants and investment tax credits for renewable energy projects. These are more helpful for the biogas industry’s overall development and result from the federal government’s climate change policy.
The federal government wants more renewable energy resources and is trying to put pollution pricing into place to encourage development in this area, but they also want to keep the peace with the general population by keeping natural gas or electricity rates low.
How can we make it work?
As the oil and gas industry is subsidized, investment tax credits and subsidies are also required for renewable energy projects. The goal moving forward should be to level the playing field. However, until recently, the price of renewable energy has only been adequate to justify renewable energy projects for agricultural producers if they produce or have access to large quantities of organic waste. One way to address this problem is to use energy crops in biogas facilities.
The scale of the European industry was achieved through the government’s incentives for energy crops as feedstock. This decision was initially criticized for removing arable land from food production. But given the current political situation in Europe and the potential disruption of foreign fuel supplies, growing fuel crops and having access to local energy production suddenly seems more of a priority.
Other than localizing energy production, there are other advantages to using energy crops, such as corn silage, to produce renewable energy. One such advantage is a reduction in capital expenditures. For example, building a facility that produces 1000 m3/hr of biogas from energy crops would cost between $15 million to $20 million, as opposed to a more complex facility for food waste, which would require an investment of between $20 million to $25 million.
Canada’s population is quickly growing, and urban areas are expanding. The pressures on farmland are not new and are not looking to ease up anytime soon. Putting government incentives in place for energy crops may help to protect farmland from development. In addition, keeping land in production keeps the option open for returning that land to food production in the future, if required.
Biogas is a valuable investment. It contributes to increased sustainability in small- to medium-sized greenhouse operations, diversifying farm operations, and contributing an interesting element to an individual farm’s succession plan. All while making the most use out of our waste streams and protecting the environment. If it were economical for greenhouses to grow energy crops for biogas production, this would create an ecosystem for sustainability and growth in the biogas market.
Tom Ferencevic, CEO of Fitec and an environmental scientist at Fitec Environmental Technologies. Fitec is a Canadian company that provides environmental and biogas solutions all across North America.
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