Oil sands facilities, both mining and in situ, use hot water or steam to extract bitumen. Heating the water requires energy: usually from either the combustion of natural gas or petroleum coke in boilers. But typically only a portion of the heat generated is used in this process. The rest dissipates into the surroundings.
In some cases, oil sands operators can make better use of this waste heat through process called cogeneration. Cogeneration is when both heat and electricity are generated at the same time from the same fuel source.
In the case of the oil sands, cogeneration usually means that in addition to generating the steam needed to extract the bitumen, excess heat from combustion is used to spin turbines that then produce electricity.
Oil sands operations require a steady source of reliable electricity. Cogeneration plants are designed to meet on-site demand. As well, for sites that are connected to the electricity grid, excess power can be sold back to the province..
Cogeneration can also provide significant environmental benefits. It generally increases energy efficiency through the effective utilization of waste heat. As well, fewer greenhouse gas emissions (GHGs) are created when cleaner-burning natural gas is used to replace existing fuel sources like coal or petroleum coke.
Benefits of cogeneration:
- Reduces GHG emissions by utilizing heat that would otherwise be a waste byproduct of combustion.
- Also reduces GHG emissions when natural gas is used to replace coal or petroleum coke as fuel sources.
- Reduces the risk of facility shutdown due to power disruption.
- Reduces operating cost by generating electricity for on-site needs.
- Generates electricity that benefits a province's residents.
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