Clear answer, explained.
Grid connection for a commercial solar system in Ontario is managed through the local distribution company (LDC) under requirements set by the IESO. The process begins with a pre-application to the LDC to confirm available interconnection capacity. Where available capacity is within the LDC's headroom, the formal application proceeds. Where capacity is limited, the LDC may require infrastructure upgrades before the system can connect — affecting project timeline and cost.
The formal process covers engineering review of the proposed system design, permit submission and municipal approval, construction of the solar array and associated electrical work, ESA inspection, and final utility sign-off with metering activation. In Ontario, net metering or net billing arrangements govern how exported electricity is credited on the facility's bill.
GI manages the full interconnection process — coordination with the IESO, the LDC, and the ESA — as part of every project. The 8–16 week interconnection timeline runs in parallel with construction where possible, so it does not extend overall project delivery in most cases.
What this means in practice.
- Commercial solar in Ontario connects through the facility's existing electrical service under IESO interconnection requirements
- The LDC manages the interconnection application for systems connecting at the distribution level
- Available LDC interconnection capacity is confirmed at pre-application — limited capacity may require grid upgrades
- The formal process covers engineering review, permits, construction, ESA inspection, and utility sign-off
- Interconnection typically runs 8–16 weeks from application to approval
- The interconnection timeline runs in parallel with construction in most cases — not extending overall project delivery
Best-fit environments.
- You are planning a commercial solar project and want to understand the grid connection process before committing
- Your utility has indicated interconnection capacity may be limited and you want to understand the implications
- You are planning project timeline and need to understand how long interconnection takes relative to construction
- You want to understand how net metering or net billing works for a commercial solar system in Ontario
