Transmission and distribution connection availability testing

A key element in determining whether grid capacity is available for a specific project lies in connection availability testing.

For micro-scale projects, the local distribution companies (LDCs) conduct the connection tests. These are projects with a nameplate capacity no greater than 10 kilowatts (kW). The OPA monitors these projects so that the 1 MW capacity reserved for micro-scale projects can be maintained where capacity is still available.

For applications under generation procurement programs, each application is subjected to tests for both transmission and distribution availability. For the FIT program, these tests are referred to as the Transmission Availability Test (TAT) and a Distribution Availability Test (DAT). Other procurement programs utilize similar tests with various names. The TAT includes technical tests for connection availability on the transmission system. It considers the impact of the generation project on transmission system equipment related to the equipment rating and safety considerations. 

Some regions of the province have generation in excess of the local needs during normal operating conditions. Long-distance, inter-area transmission lines transfer the excess generation to load centres in other parts of the province. However, there are areas in the province where the required transfer levels are greater than the capability of the inter-area transmission facilities. These “area limits” are considered in the TAT process. Depending on the size of the proposed project, applications in these areas would not be offered a contract. Please refer to this map, which shows area capabilities and limits.

However, generation procurement projects that are 500 kW or smaller may be allowed in these areas, recognizing the size and nature of the programs. The OPA closely monitors the program uptake in these areas.

The DAT is conducted by the LDC. This test considers the connection availability on the distribution system. Distribution-connected applications are subjected to the DAT as well as the TAT, as they also have an impact on upstream transmission system equipment. It is possible for projects to pass the DAT but not the TAT, and vice versa.

For generation procurement, only complete and eligible applicants that pass all the applicable tests under TAT and DAT will be eligible to be offered a contract. Other parameters, such as procurement targets, may also affect whether a project is offered a contract. Please note that the TAT and DAT are connection screening process tests; formal connection assessments such as a System Impact Assessment and/or a Connection Impact Assessment would still be required for the connection of generation projects.

Applications for conservation BMG WER projects are not subject to TAT, DAT or area limit testing by the OPA. WER projects are tested for technical connection issues by LDCs and/or transmitters as necessary and required. These tests consider the project’s technical impact on the distribution or transmission system.

Applications for conservation BMG CHP projects are subjected to TAT, DAT and area limit testing. If a CCHP project application is found to be in an area with excess generation, then the OPA ‎will determine whether an incentive should be provided for such a project. Factors that will be considered include the size of the project, long-term cost-effectiveness, economic impact on the applicant and the local community, and contribution to the LDC conservation target.