Your inverter converts the DC electricity your solar panels produce into AC electricity your home uses. It's the brain of your solar system. There are two types: string inverters and microinverters. We install microinverters exclusively. Here's why.
How string inverters work
A string inverter connects all your panels in series — like old-fashioned Christmas lights. All DC power flows from the panels to a single inverter box (usually mounted in your garage or basement), which converts everything to AC at once.
The problem: When panels are connected in series, the weakest panel limits the entire string. If one panel is shaded by a chimney, covered in snow, dirty, or underperforming, every panel on that string drops to match it. One shaded panel can reduce your entire system's output by 20–30%.
How microinverters work
A microinverter is a small inverter attached to each individual panel. Each panel operates independently — converting DC to AC right at the panel. If one panel is shaded or underperforming, the others are completely unaffected.
We install the APsystems DS3, a dual-module microinverter that handles two panels per unit. It's one of the most reliable microinverters on the market with a 25-year warranty.
Why microinverters win in Alberta
Snow handling: Alberta gets snow. With a string inverter, one snow-covered panel drags down every panel on the string. With microinverters, the uncovered panels keep producing at full capacity while the snow melts off the covered ones. Over a winter, this difference adds up to 5–15% more production.
Shade tolerance: Most residential roofs have some shading — chimneys, vents, plumbing stacks, nearby trees. Microinverters handle partial shading without system-wide losses. String inverters can lose disproportionate production from minor shading.
Panel-level monitoring: The APsystems monitoring platform shows you exactly how each panel is performing in real time. If a panel underperforms, you know immediately which one and why. With a string inverter, you only see total system output — if production drops, you don't know if it's one panel or ten.
Safety: Microinverters convert to AC at the panel, so there's no high-voltage DC running through your roof and walls. String inverters carry 300–600V DC from the roof to the inverter. In a fire scenario, firefighters are trained to be cautious around DC voltage on rooftops. Microinverters eliminate this risk.
Expandability: Want to add more panels later? With microinverters, you just add panels with their own microinverters. With a string inverter, adding panels may require replacing the entire inverter if it's maxed out.
The case for string inverters
String inverters cost less upfront — typically $1,000–$2,000 less on a residential system. They also have fewer components on the roof, which theoretically means fewer potential failure points. For a perfectly unshaded, south-facing roof with no obstructions, a string inverter can perform comparably.
However, most Alberta homes don't have perfect roofs. And the cost difference has narrowed significantly as microinverter prices have dropped.
The comparison
| Factor | String Inverter | Microinverters (APsystems DS3) |
|---|---|---|
| Shade handling | Entire string affected | Only shaded panel affected |
| Snow performance | Reduced by weakest panel | Unaffected panels keep producing |
| Monitoring | System-level only | Panel-level real time |
| Safety | High-voltage DC on roof | AC only — no DC risk |
| Warranty | 10–15 years typical | 25 years (APsystems DS3) |
| Expandability | May require inverter replacement | Add panels anytime |
| Upfront cost | Lower | Slightly higher |
| Lifetime production | Lower (shade/snow losses) | Higher (independent optimization) |
Our recommendation
For Alberta homes, microinverters are the clear winner. The combination of snow, partial shading from rooftop obstructions, and the value of panel-level monitoring makes them the better long-term investment. The slight upfront cost premium is recovered through higher lifetime production.
We install the APsystems DS3 on every system. 25-year warranty. Panel-level monitoring included. No subcontractors.