How the Solar Interconnection Process Works in Ontario and Beyond

Introduction: Why Interconnection Matters

Installing solar panels is a major win for your energy bills and the environment but before they can start generating power, they must be safely connected to the electrical grid. That process is called interconnection, and it’s a mandatory step across all Canadian provinces.

In this article, we’ll walk you through how solar interconnection works in Ontario (with tips for other provinces), how long approvals typically take, and what you should absolutely avoid if you want a smooth project.

Section 1: What Is Solar Interconnection?

Solar interconnection is the process of formally connecting your rooftop solar system to the utility grid. It ensures that your system:

• Can safely export excess electricity back to the grid
  
• Qualifies for programs like net metering
  
• Meets local and provincial utility safety standards
  

This process is handled differently in each province, but in most cases, you (or your installer) must submit technical documents to the utility and wait for approval before flipping the switch.

Section 2: Ontario’s Interconnection Process (Step-by-Step)

Ontario’s solar interconnection is managed by local distribution companies (LDCs) such as Hydro One, Alectra, or Toronto Hydro. Here’s what a typical interconnection process looks like:

Step 1: Pre-Consultation (Optional but Recommended)

Some utilities allow or require a pre-consultation to confirm your project is feasible. This is especially important if your neighborhood has high solar penetration.

Step 2: Connection Impact Assessment (CIA)

If your system is above 10 kW (common in commercial or rural homes), you may need a Connection Impact Assessment to evaluate grid impact. This takes about 30 to 60 days and costs extra.

Step 3: Submit an Application for Net Metering

For residential projects, your installer will submit:

• Single-line diagram of your system
  
• ESA (Electrical Safety Authority) design plan
  
• Component spec sheets
  
• Net metering application
  

Once received, the LDC will review your documents and issue a conditional approval.

Step 4: Installation and ESA Inspection

Once you get conditional approval, you can begin installation. After that:

• The ESA performs a site inspection
  
• They issue a Connection Authorization if it passes
  

Step 5: Final Utility Connection

The utility gives you a connection agreement and installs a bi-directional meter that tracks energy in both directions. You can now start generating and exporting electricity.

Section 3: What to Expect Outside Ontario

While Ontario has one of the most detailed solar interconnection processes, other provinces have similar structures with a few key differences:

Province	Utility	Net Metering Program	Approval Timeline
British Columbia	BC Hydro	Yes	2–4 weeks
Alberta	ENMAX, EPCOR	Yes (regulated differently)	Varies
Quebec	Hydro-Québec	Yes	4–6 weeks
Nova Scotia	NS Power	Yes	3–5 weeks

Each utility has its own forms, documents, and approval processes—so always double-check with your installer or utility before starting.

Section 4: Common Interconnection Delays and How to Avoid Them

Several issues can delay or derail your interconnection:

• Incorrect paperwork: Incomplete or outdated documents are the #1 cause of rejection.
  
• ESA inspection delays: Book your inspection early, especially in spring and summer.
  
• Lack of load capacity: Some neighborhoods are too full to accept more solar—check in advance.
  
• Unlicensed installers: Only certified professionals can submit interconnection documents.
  

Pro Tip: Work with installers who handle utility paperwork and ESA coordination. This alone can shave off weeks of waiting time.

Section 5: What Not to Do Before Final Approval

It’s tempting to turn on your solar system as soon as it’s installed—but doing so before final approval is a serious violation that can:

• Void your net metering eligibility
  
• Trigger utility penalties
  
• Damage your system if the grid isn’t ready
  

Always wait until your utility installs the bi-directional meter and issues an official Permission to Operate (PTO).

Conclusion: Plan Early, Avoid Surprises

The solar interconnection process may seem technical, but with the right installer and a clear roadmap, it’s totally manageable.

Whether you’re in Ontario, BC, or beyond, make sure you understand your local utility’s requirements and timelines so you can avoid costly delays.