Comparisons
Monocrystalline or polycrystalline panels
Choose monocrystalline. It converts more of the same roof area and the price gap has narrowed to the point where poly rarely wins on cost per watt. Poly only makes sense where roof space is genuinely unlimited and the cheapest possible per-watt figure is the only consideration.
Last reviewed
The difference that actually matters
Monocrystalline cells are cut from a single silicon crystal and convert a higher share of the light hitting them, so the same wattage takes less roof. Polycrystalline is made from cast fragments, is slightly less efficient, and historically cost less. Manufacturing has moved so far toward mono that the price advantage has largely disappeared.
Why efficiency matters on a Pakistani roof
Most houses here have finite usable slab — parapets, water tanks, stairwell housings and shading all eat into it. Higher efficiency means more kW fits in the space you actually have, which for a constrained roof is the difference between covering your load and covering most of it. On an unconstrained roof, the advantage is worth less.
Heat behaviour, which is not a marketing point here
All panels lose output as they heat, and Pakistani rooftops get very hot. The temperature coefficient on the datasheet tells you how much per degree, and it varies more between manufacturers than between mono and poly. On a roof that reaches high surface temperatures for months, that number deserves more attention than the cell type does.
What to compare instead
Warranty terms, the guaranteed output at year twenty-five, the temperature coefficient, and whether the manufacturer has any presence in Pakistan for a warranty claim. Those four separate good panels from poor ones far more reliably than the mono-versus-poly label, which is now close to settled.
Are monocrystalline panels better than polycrystalline?
Do bifacial panels make sense on a house?
Rarely. Bifacial panels harvest light reflected onto their rear face, which needs a bright surface below and a mounting height that lets light get under them. On a typical flat slab with panels close to the roof, the extra yield is small and the extra cost is not. They earn their keep on ground mounts over light surfaces.
How much output do panels lose over time?
Most manufacturers warrant a guaranteed percentage of original output at year twenty-five — usually in the low eighties. Real degradation is gradual and modest. What people mistake for degradation is almost always dust, which costs far more output in a Pakistani year than ageing does and is fixed with a wash.
Does panel brand matter much?
It matters for the warranty, not the physics. Two panels of the same wattage and similar temperature coefficient produce similar energy. Where brands differ is whether a twenty-five-year warranty means anything — a manufacturer with no presence here is a warranty you cannot claim against, which makes it a marketing line rather than a term.
Rather have it done?
Solar installation covers the survey, the panels, the mounting structure, DC and AC wiring, protection and commissioning. A 3kW on-grid system in Islamabad starts near PKR 350,000 complete, and the figure that matters is the one that includes structure and wiring rather than panels alone.
Solar panel supply and installation in Islamabad — prices and scope