Solar Panel Selection Guide

Last reviewed: October 2026

Panels determine how much energy your roof can generate. Wattage matters, but so do physical size, voltage, technology and warranty.

Wattage and roof area

Higher-wattage panels generate more energy from the same roof area. A modern high-power panel is physically large — roughly 2.2–2.4 m by 1.1 m — so measure your usable roof area, allow for walkways, water tanks and shade, and count how many panels will actually fit.

Panel technology

• Monocrystalline (mono): the most common type for new systems, with good efficiency per square metre.
• N-type / TOPCon and similar newer designs: often offer better performance in heat and lower degradation; ask for the datasheet to compare.
• Bifacial: collect some light from the rear side and can give extra output with a reflective surface below, but need suitable mounting.

Electrical specifications that must match your inverter

• Open-circuit voltage (Voc): the series string voltage must stay below the inverter's maximum input voltage, even on cold mornings.
• Maximum power voltage (Vmp): the string should sit inside the inverter's MPPT range.
• Current (Imp / Isc): must be within the inverter's per-input current limits.

We check these numbers for you when you share your inverter model. See also the inverter guide.

Warranty

Panels usually carry a product warranty and a separate performance (power output) warranty. The terms differ by manufacturer, so ask for them in writing before you order.

Installation factors

• Orientation and tilt: in Pakistan, panels generally face south at a tilt close to the latitude for best annual output.
• Shade: even partial shade can reduce a whole string's output.
• Dust and cleaning: dust reduces output; plan for safe access to clean the panels.
• Mounting structure: choose corrosion-resistant, wind-rated structures — see solar accessories explained.

Next steps

Explore our solar panels and use the sizing guide to estimate how many you need.