The Alberta Utilities Commission on Feb. 22 approved Exshaw Oil Corp. to transmit to the grid power out of a relatively new 10.7-MW, natural gas-fired plant located 16 kilometers southwest of Spirit River.
The plant would interconnect to the ATCO Electric Ltd. 25-kV distribution system. The commission in 2014 had approved an exemption for the plant related to a normal need for commission approval prior to constructing or operating a power plant. The exemption was granted on the condition that the power plant would generate electric energy solely for Exshaw’s own use and would not export electric energy onto the Alberta Interconnected Electric System.
In an August 2015 application, Exshaw stated that it planned to export energy from the power plant to the ATCO Electric distribution system and to import energy from the distribution system via the interconnection.
The power plant consists of four 2,666-kW natural gas-fired generators and has a total capability of 10.7 MW. It began operations in late 2014 to provide electricity to a sour gas processing plant owned and operated by Exshaw.
Exshaw explained that when it first sought the commission’s approval to construct the power plant it requested an exemption because it was unable to provide an interconnection proposal at that time. After the power plant commenced operations, Exshaw and ATCO Electric continued to discuss options in order to develop a long-term interconnection solution that would allow the sour gas processing plant to be served by energy imported from the ATCO Electric distribution system and would allow the power plant to export energy on to the Alberta Interconnected Electric System during peak power price and peak transmission loading periods.
In April 2015, ATCO Electric proposed an interconnection between the power plant and its distribution system to Exshaw. This proposal contained certain constraints on imports and exports. Specifically, the export capability is constrained to 6,500 kW and the import capability is constrained to 500 kW due to voltage limits in the surrounding distribution system.