Solar panels
UTL modules from 40 W panels for a single light up to 735 W half-cut modules for large rooftop and commercial systems, in mono PERC, N-type TOPCon and bifacial. What the numbers on a datasheet mean, and the one check that decides whether you get the subsidy.
Updated 11 September 2026
Reading a panel datasheet
- Maximum power (Pmax) is the rating in watts at standard test conditions: 1000 W/m² of sunlight at a cell temperature of 25 °C. Punjab rooftops in May run far hotter than that, so real midday output is lower, and our calculator allows for it.
- Module efficiency is the share of sunlight turned into electricity. Higher efficiency means more watts per square foot of roof, which matters when the roof is small.
- Voc and Isc are the open-circuit voltage and short-circuit current. The installer uses them to match the panel strings to the inverter.
- A positive power tolerance means the panel won’t produce less than its rating at test conditions.
- UTL lists a 25-year performance warranty on its panels, and the product warranty for defects is separate. Check both on the datasheet for the model you buy.
The check that decides the subsidy
PM Surya Ghar only pays for systems built with DCR modules from the ALMM list, meaning panels made in India with Indian-made cells. The inspector checks the model, and if it isn’t on the list the subsidy is lost and can’t be recovered after installation. Ask for the exact model number on your quote and check it against the current ALMM list before the panels go up.
Panels alone, or a complete system?
If you are replacing panels or adding to an existing system, match the voltage and current to your inverter or charge controller. If you are starting from scratch, buy a matched system, with the panels, inverter, mounting structure and wiring designed together. That avoids the mismatches that waste generation.
Questions we are asked
Mono PERC, TOPCon or polycrystalline?
For rooftop systems, a mono module. N-type TOPCon panels turn a little more sunlight into power than mono PERC and lose less output as they heat up, which counts on a Punjab roof in May. Bifacial versions also collect light reflected up from the roof surface. Small polycrystalline panels still make sense for lighting kits and small off-grid loads, where cost matters more than space.
How much roof does a panel need?
A 72-cell module of 390 to 400 W is roughly 2 m long and 1 m wide. For a complete system, allow about 100 sq ft of shade-free roof per kW, including the gaps between rows for access and to avoid shading.
Do the panels need to be DCR and ALMM-listed?
For the PM Surya Ghar subsidy, yes. A subsidised home system needs DCR panels, made with Indian-made cells, of a model on the government’s ALMM list. We confirm both for the exact model on your quote before installation.