Climate smart agriculture – Renewable energy

Overview

Renewable energy is generated from sources that can be restored indefinitely, while complementing, reducing or replacing conventional fossil fuel energy sources which lower carbon dioxide (CO₂) emissions. Adaptation to changing climates is increased by diversifying from traditional, centralized energy sources.

Wind, solar and small-scale hydro systems have zero greenhouse gas (GHG) emissions while generating power. This energy can be sold to supply the provincial power grid that is operated by the Alberta Electric System Operator. For more information on how to generate your own electricity, visit the Alberta Utilities Commission Micro-generation page.

Biomass sources of energy are considered GHG neutral because the CO₂ generated by producing the energy is offset by the growing crop. Table 1 below outlines various sources of energy and rates of emissions in Alberta relative to fossil fuel sources (coal and natural gas).

Table 1. Estimated emissions by technology in Alberta

Renewable energies

Wind energy

Wind turbines capture wind energy and convert it to electricity. Systems range from small ‘off-grid’ to utility-scale towers that contribute to the provincial power grid. Average annual wind speeds of greater than 15 kilometres per hour are required.

Alberta has abundant wind energy resources. The Canadian Wind Energy Association (CANWEA) reported that, as of December 2019, over 1,685 megawatts (MW) connected to the grid, or enough to serve 431,862 homes in Alberta. Most of the province’s wind turbines are located in southern Alberta near Pincher Creek.

Solar energy

Solar power is energy from the sun that is converted into thermal or electrical energy. Solar energy is the cleanest and most abundant renewable energy source available. Southern Alberta is one of the regions in Canada with the highest solar potential.

Types of solar installations used to generate heat or electricity:

• Passive systems: collect and store solar energy and distribute it by natural processes such as convection and radiation. For example, houses constructed with large double- or triple-paned windows that get direct sunlight to capture and magnify the sun’s warmth.
• Active systems: use the same principles as passive systems except that they use a fluid (such as water) to absorb the heat. A solar collector positioned on the roof of a building heats the fluid and then pumps it through a system of pipes to heat the whole building. Canadian agricultural businesses using solar systems include dairy, swine and poultry producers.
• Photovoltaic (PV) systems: involve photovoltaic cells, or solar panels and are slightly more involved than passive or active solar energy systems. They convert sunlight to electricity by using thin sheets of silicon. These thin sheets are inexpensive and can be easily added to roof structures. The added benefit is that a solar PV system is the best choice to integrate with your whole farm or home while connected to the provincial energy grid. This connectivity ensures a consistent power supply while channelling surplus solar energy back to the grid. This provides homeowners the opportunity to offset their electrical bills substantially, while also earning a credit for surplus generation.

Farmers across Alberta have installed solar panels of varying sizes to generate energy for use in barns, feedlots, irrigation systems, greenhouses and other applications. A number of agricultural solar installation case studies can be found on Solar Alberta’s website.

Geothermal energy

Geothermal energy provides heating in winter, cooling in summer and year-round hot water. Pumps move heat between the earth and buildings as needed. Installation costs are about twice as much as conventional, but operating costs are about two-thirds less than traditional systems. They are considered to be the most energy-efficient, environmentally clean and cost-effective heating systems available.

Research from the University of Alberta has identified potential to develop this resource on a commercial scale with more than 6,100 megawatts of thermal power capacity potential and more than 1,150 megawatts of technically recoverable electrical power capacity potential across several municipal districts in western Alberta.

Rural installations of ground-source heat pumps can take advantage of open area by laying out systems horizontally (trenching) rather than vertically (drilling). Trenching costs tend to be substantially more affordable than drilling costs. The industry can also use existing oil and gas wells to assist in the extraction of geothermal energy.

Hydro energy

Hydroelectric power systems use free-flowing water to produce electricity. Most are run-of-stream systems that divert water through a pipe or channel. Water is directed through a turbine and then allowed to flow back to the river or creek. Installations can be sited, built and operated with minimal environmental impact.

Biomass energy

Biomass resources are any plant-derived organic matter available on a renewable basis. This includes forestry and agricultural crops, in addition to animal, food-processing and municipal wastes. Biomass is converted into energy by incineration (complete combustion), gasification or pyrolysis (absence of air and presence of extreme heat).

Agriculture operations producing feedstock can benefit by using biomass on-farm or selling it to producers of bio-energy products. Feedstock can include wood, straw and switchgrass. Table 2 below outlines the heat content per unit mass of a range of biomass feedstock relative to fossil fuels.

Table 2. Heat content* per unit mass of various fuels ¹

Biogas – anaerobic digestion

Anaerobic digestion is a naturally occurring process that can be harnessed to transform organic waste into a mix of methane (CH₄) gas and CO₂ (usually referred to as ‘biogas’). Generated by the anaerobic (no oxygen) digestion of organic material such as manures and municipal wastes, biogas can be burned to produce heat, electricity or both.

Liquid manure works best for anaerobic digestion. However, semi-solid can also be used. The installation and operation of an anaerobic digester requires considerable monetary and manpower investments. The feasibility of anaerobic digesters depends on type of livestock, type of manure management system, heat and electricity requirements. The cost and continuity of feedstock supply requires careful evaluation.

Biofuels

Biofuels include biogas, bioethanol, biodiesel and other chemicals made from biomass resources. Biofuels can be used as a supplement or an alternative to fossil fuel to produce electricity, heat /or transportation fuel. In the short-term, biofuels can be used as blending agents to reduce CO₂ emissions from fossil-based fuels. In the long-term, technological advances are expected to allow greater use of biofuels in vehicles.

Bioethanol

Bioethanol (fuel alcohol) is made from starch (grain crops, corn), sugar (sugar beet or sugar cane), and although still in the preliminary stages, from cellulose (wood, straw, grass or municipal solid waste). Bioethanol is widely used in Brazil and the USA today. Ethanol-blended fuels such as E85 (85% ethanol and 15% gasoline) can reduce net GHG emissions by as much as 37%, and E10 (10% ethanol and 90% gasoline) can reduce net GHG emissions by almost 4%.

Biodiesel

Biodiesel is manufactured from most vegetable oils such as canola or soybean, animal fats, recycled grease, as well as low quality oilseeds and tall oil produced from wood pulp waste. Biodiesel can be blended with conventional diesel fuel or used ‘straight’ (100% biodiesel). It is typically added to petroleum diesel in 20% blends (B20) for diesel engines and is a direct fuel substitute for #2 petroleum diesel. Biodiesel used as a fuel or additive requires little or no engine modification and bio-diesel fuelled engines deliver similar mileage, torque and horsepower. Compared to fossil fuels, it degrades quickly in the environment and is nontoxic.

The Canadian Renewable Fuel Regulations require fuel producers and importers to have an average renewable fuel content of at least:

• 5% based on the volume of gasoline and
• 2% based on the volume of diesel fuel and heating distillate oil

The combination of improved technological efficiencies, scientific advances, increased environmental awareness and environmental protection regulations have turned biomass conversion into a cleaner, more efficient process. The biomass energy market may provide farms with another stream of income.

Related

• Agricultural carbon offsets
• Renewable fuels
• Energy, utilities and surface rights
• Waste to energy facilities
• Alberta Utilities Commission