PV design, and the calculation everything turns on.

If you learn one thing properly out of all of this, learn to size a string across the site's full temperature range. It is the most common examination question, the most common field error, and the most expensive mistake in residential PV.

What design content covers

1. Solar resource. Irradiance against insolation, peak sun hours and why it is a useful fiction, orientation and tilt, and shading assessed across the year rather than at the moment of the site visit. Where Canadian data comes from and how to read it.
2. Module behaviour. The IV curve and the power curve. Open-circuit voltage, short-circuit current, maximum power point. Temperature coefficients, and the fact that a module performs better cold — which is good for yield and the reason strings fail in winter.
3. String sizing. Series and parallel configuration. Matching the string's voltage range to the inverter's input window at both temperature extremes. Maximum string length set by the coldest expected temperature; minimum set by the hottest. A fully worked example →
4. Inverters. String, microinverter and optimiser architectures, and the cases for each. DC-to-AC ratio and why deliberate oversizing is sometimes correct. Efficiency curves, and why peak efficiency is not the number that matters.
5. Conductors and protection. Sizing for ampacity with the deratings that apply, voltage drop across a long DC run, overcurrent protection, and the labelling a PV system requires under the Canadian Electrical Code.
6. Mechanical design. Racking selection and span, attachment, wind and snow loading, thermal expansion, and the roof-penetration detail that produces callbacks years later.
7. Yield estimation. Turning an array size into an annual energy figure with realistic loss assumptions — soiling, temperature, mismatch, wiring, inverter — and understanding why an optimistic estimate is a commercial problem rather than a technical one.

Taught against the Canadian Electrical Code

The design content is taught against the CEC, which is the code that governs the work here. Where a requirement is provincial, or a utility's rather than the code's, we say which — because generalising across jurisdictions is how people arrive on site with the wrong answer. The NABCEP examination itself is a North American examination and leans on the US code; we teach both contexts and are explicit about which is which, rather than letting a candidate discover the difference in the exam room.

The one calculation to drill

Temperature-corrected open-circuit voltage, and the string length it permits. Voltage rises as temperature falls. A string that measures comfortably within the inverter's window in October can exceed its maximum input on a clear January morning, and the inverter is then damaged by a design decision made months earlier. Get this right and a large fraction of both the examination and the job is handled.

Where it is taught

Day two of the four-day Fast-Track, and the design modules of the forty-hour self-paced course. Drilled in the question bank, which is weighted toward this domain for exactly this reason. If you are stuck on one specific calculation, an hour one-to-one at $150 CAD is usually faster than another forty hours of video.

Common questions