Equipment choices still matter, but usually through performance and design flexibility more than upfront dollars. In recent quote data, about 97% of solar panels offered to homeowners fall in the 400 to 460 watt range per panel.
That's why you'll often see 18 to 30 panels on a typical home depending on your target offset and roof area. Higher-wattage panels can reduce panel count and sometimes simplify racking and wiring, but the better question is whether the chosen panel fits your roof geometry.
Inverters are a common hidden lever in both price and performance. String inverters are typically the lowest-cost route when you have a single, unshaded roof plane. Microinverters and DC-optimized systems can cost a few thousand dollars more.
They can be worth it when the roof is chopped up into multiple planes, has partial shading, or you want panel-level monitoring. When you compare solar panel quotes, ask each installer to explain why the inverter approach fits your roof.
Roof design and solar panel angle orientation can quietly swing your economics. In most of the U.S., arrays facing close to true south generally maximize annual production, but east and west-facing roofs can still make excellent financial sense.
Tilt is similar: the perfect tilt depends on latitude and whether you care more about summer or winter output, but in practice many successful residential systems are mounted flush to the roof pitch.
The bigger red flags are shading from trees, chimneys, dormers and a roof that's near end-of-life. If you might need a roof replacement in the next decade, it's often cheaper to do it before solar to avoid paying for a remove-and-reinstall later.