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Connection Impact Assessment (CIA)

​​​​​​​​​A CIA is a more detailed assessment of a project's impact to the grid. The results include a technical report outlining project feasibility, technical specifications needed for the project and the impacts the project would have on the distribution grid.

A complete CIA application consists of the following items, which can be found here:

  • Completed and signed CIA Form
  • Payment in full by cheque payable to "Hydro One Networks Inc." (see Connection Impact Assessment Fee Schedule below)
  • Signed Study Agreement
  • Single Line Diagram (SLD)
  • Distribution Operating Map (DOM)

All technical submissions (Form B, single line diagrams, etc.) for projects greater than 10 kW must be signed and sealed by a licensed Ontario Professional Engineer (P.ENG).



**New CIA fee effective January 1, 2017​


(As of 
January 1, 2016)
Previous Category
Project Sizes
CIA Type
*Threshold Allocations

CAE Small DG & Net Metering​
Small Capacity Allocation Exempt (CAE), Net Metering
Must be 3-phase generation facility and either:

*a) >10 kW and ≤30 kW and connecting to less than 15 kV

*b) >10 kW and ≤100 kW and connecting to ≥15 kV

January 1, 2016

January 1, 2016
Must not be a microFIT facility or​​ option a) or b) above, and:

c) >10 kW and ≤500 kW

d) ≤250kW connected on distribution system voltage <15 kV​

e) ≤500 kW connected on distribution system voltage ≥15 kV

January 1, 2017
Greater than CAE Small DG & Net Metering
Small (non-CAE), Mid-Sized, Large
f) ≤10 MW but >25 0 kW connected on distribution system voltage <15 kV

g) >500 kW but ≤10 MW connected on distribution system voltage ≥15 kV

h) >10MW

January 1, 2017


  • *The "Threshold Allocation Assessment (TAA)" process has been changed to the "Threshold Allocation (TA)" process. TA applicants now receive an Agreement Letter from Hydro One acknowledging capacity based on Bus Type as opposed to previous classifications based on "Inverter Based" and "Load Displacement". The fee for a Threshold Allocation (TA) is $500, the fee does not vary according to project size
  • **Criteria a) and b) in the CIA Fees Table above, including cost, became effective January 1, 2016 for qualifying CAE Small DG & Net Metering CIA applications.​
  • ***New CIA fee effective January 1, 2017​.
  • ​The Ontario Energy Board approved an increase in Delivery rates effective May 1, 2015. Revised CIA fees were included in the approval. The new rates are reflected in the CIA Fees Table.
  • Refund policy: Cost not spent will be refunded if the CIA is withdrawn before completion.
  • CIA revisions will be charged 50% of the CIA costs listed in the table above.
  • An additional $10,000 will be required for projects that involve another LDC (does not apply to Net Metering projects).
  • Please note that the costs listed above do not include applicable taxes (HST).
  • Please also note the costs are only for the CIA application. Hydro One will perform the CIA study and send a completed CIA report to the customer outlining any additional costs to connect their facility to Hydro One's Distribution System.

For questions, email DxGenerationConnections@HydroOne.com or call 1-877-447-4412 (option #2).
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