Monocrystalline vs Polycrystalline vs TOPCon: Which Solar Panel Type for Bangalore Homes (2026)
Direct answer: Choose monocrystalline. Mono panels make more power from the same roof, and in 2026 they are almost the only panels being made: the industry’s technology roadmap (ITRPV) found no polycrystalline wafers on the market in 2025. The real choice for a Bangalore home today is between mono types, mainly TOPCon and mono PERC, and whether the panel is DCR (Indian cells) so you keep the PM Surya Ghar subsidy of up to ₹78,000.
If your quotes still say “mono vs poly”, the comparison is out of date. This guide explains the difference, what replaced polycrystalline, how heat and mounting affect output on a Karnataka roof, and what to check on the quote.
Monocrystalline vs polycrystalline at a glance
| Monocrystalline | Polycrystalline | |
|---|---|---|
| How the cell is made | Cut from a single silicon crystal (Czochralski process) | Cast from many silicon crystals melted together |
| Look on the roof | Uniform black | Blue and speckled |
| Output from the same roof | Higher, because each panel makes more watts per square metre | Lower; needs more panels and more roof for the same kW |
| Where the market is in 2026 | Almost all panels made today, as mono PERC, TOPCon or HJT | Effectively gone from mainstream production |
| Fit for a Karnataka home | The default choice | Only if a quote clearly beats mono on price and still meets the subsidy rules |
Market status: ITRPV 17th edition (VDMA, June 2026).
What replaced polycrystalline: panel types in 2026
Almost every panel sold now is monocrystalline. What differs is the cell design on top of the mono wafer. In 2025, TOPCon made up about 75% of crystalline cell production, PERC about 14% and HJT about 5%, according to ITRPV.
| Panel type | What it is | Typical module efficiency (2025) | Fit for a Bangalore home |
|---|---|---|---|
| TOPCon (n-type mono) | A mono cell with a thin passivating oxide layer; now the most-made cell in the world | About 23.5% | Strong choice when the price gap over PERC is small |
| Mono PERC (p-type) | The older mono design with a reflective rear layer; being phased out | About 21.7% | Still a sound panel; check degradation and warranty |
| HJT (heterojunction) | A mono cell layered with thin amorphous silicon | About 23.5% | Good heat performance; less common and usually dearer |
| Bifacial | Glass or clear back, so the rear side also collects reflected light | Rated on the front side; rear gain depends on mounting | Pays off on a raised structure over a light surface |
| Half-cut | Cells cut in half to cut resistive losses and soften partial shade | A feature, not a cell type | Most modern mono panels already have it |
| Polycrystalline | Multi-crystal cells, the older technology | Not tracked; no longer in mainstream production | Rarely the right buy now |
Efficiency and share figures: ITRPV 17th edition (2026), typical mass-production modules. Your panel’s datasheet is what counts.
The type matters less than the datasheet. Two TOPCon panels can differ more than a good PERC and an average TOPCon, so compare the numbers side by side. Our guide to the best solar panels for home lists the eight checks.
Heat: the number that matters on a Karnataka roof
Panels are rated at a 25°C cell temperature, but a panel on a sunny terrace runs far hotter. Every degree above 25°C costs a fixed share of output, given as the temperature coefficient. MNRE’s PM Surya Ghar specification asks for −0.4%/°C or better. Here is what that means for a 540 W panel at an example cell temperature of 65°C:
| Temperature coefficient | Output lost at 65°C cell temperature | A 540 W panel then gives about |
|---|---|---|
| −0.40%/°C (MNRE’s limit) | 16% | 454 W |
| −0.35%/°C | 14% | 464 W |
| −0.30%/°C | 12% | 475 W |
Worked example using the coefficient alone; real output also depends on sunlight, wiring and inverter losses.
A better coefficient is worth a few percent of output every hot afternoon for 25 years. For how panels age in Indian weather, read solar panel lifespan and warranty.
Bifacial panels, raised structures and white roofs
A bifacial panel only gains when light reaches its back. That depends on height and on the surface beneath. The best local evidence so far is a field comparison TerraEnerG published for two 5 kW plants on the same street in a Bengaluru villa community, with the same Adani 620 Wp TOPCon bifacial panels and the same inverter:
| Flush mount | Raised structure | |
|---|---|---|
| Height above roof | About 100 mm | About 3.5 to 5.5 ft |
| Surface beneath | Puff sheet roof | Concrete with ordinary white paint |
| Tilt | About 8° | About 13° |
| Generation, 1 to 26 Oct 2026 | 550.3 kWh | 633.0 kWh (+15%) |
Source: TerraEnerG case study, raised vs flush bifacial, updated 27 October 2026 (inverter app data).
Read it carefully. The flush plant was shaded after about 3 pm, and the raised one also had a steeper tilt and a white surface, so the 15% is a combined effect. Before the shade arrived on 10 October, the gap was about 10%. It is one month of data from two homes, not a lab test. Still, it shows the pattern: bifacial panels earn their keep when raised over a light surface, not when laid flat on a dark roof. A raised structure costs more and must be designed for wind load, so it is a roof-by-roof decision. Our rooftop solar requirements checklist covers roof space and load.
DCR matters more than the cell type
For a home claiming PM Surya Ghar, MNRE requires panels made in India with Indian-made cells. Non-DCR panels in any form make the installation ineligible for the subsidy of ₹30,000 per kW for the first 2 kW and ₹18,000 for the third, capped at ₹78,000. KERC’s August 2026 tariff order used average module prices of ₹22.3 per Wp for DCR and ₹13.8 per Wp for non-DCR, excluding GST. The full comparison is in DCR vs non-DCR solar panels.
What your quote should name
- Panel maker, exact model and wattage, and the cell type (TOPCon, PERC or HJT)
- DCR status, with the maker’s DCR certificate, and the ALMM listing
- Temperature coefficient, first-year and yearly degradation, and the output warranty
- Whether the panels are bifacial, and the structure height if they are
- Panel count and roof area; MNRE estimates 10 to 12 sq m of shadow-free roof per kW (see how many panels a Bangalore home needs)
Before you sign, run through our 12 questions to ask your installer, and see the rooftop solar cost guide for Bangalore for full system prices after subsidy.
The right panel for your roof
Eltron runs a 3D shadow analysis, recommends the panel type and mounting for your roof, and names the exact DCR panel on an itemised quote, with 0% EMI options, subsidy help and 5 years of free maintenance.
FAQ: mono, poly and TOPCon panels
What is the difference between monocrystalline and polycrystalline solar panels?
Monocrystalline cells are cut from a single silicon crystal, look uniformly black and produce more watts from the same roof area. Polycrystalline cells are cast from many crystals, look blue and speckled, and produce less per panel. Polycrystalline has effectively left mainstream production: the 2026 ITRPV technology roadmap found only monocrystalline wafers on the market in 2025.
Which is better for a home in Bangalore, monocrystalline or polycrystalline?
Monocrystalline. It gives more output per square metre of terrace and is what nearly every maker now produces, as mono PERC, TOPCon or HJT. For a PM Surya Ghar subsidy, the panel must also be DCR (made with Indian cells) and on MNRE’s approved list, which matters more than the cell type.
Is TOPCon better than mono PERC?
On paper, usually yes. The ITRPV roadmap puts typical 2025 module efficiency at about 23.5% for TOPCon against 21.7% for PERC, and TOPCon now makes up about 75% of cell production. Compare the actual datasheets on your quote: the temperature coefficient, first-year and yearly degradation, and warranty.
Are bifacial panels worth it on a home roof?
They can be, if the panels sit on a raised structure over a light-coloured surface. In a Bengaluru field comparison published by TerraEnerG, a raised 5 kW bifacial plant made 15% more than a flush-mounted one from 1 to 26 October 2026, about 10% before the flush plant was shaded. Flush on a dark roof, the rear side gains little.
Does heat in Karnataka reduce solar panel output?
Yes. Panels lose a fixed share of output for every degree above 25°C, shown as the temperature coefficient on the datasheet. MNRE’s PM Surya Ghar specification asks for −0.4%/°C or better; a panel at −0.30%/°C loses noticeably less on a hot afternoon.
Are polycrystalline panels cheaper in 2026?
There is no reliable 2026 price list for polycrystalline panels in India because they are now rare. The price gap that matters today is DCR against non-DCR: KERC’s August 2026 order used ₹22.3 per Wp for DCR modules and ₹13.8 per Wp for non-DCR, excluding GST. Subsidy homes need DCR panels.
Sources
- International Technology Roadmap for Photovoltaics (ITRPV), 17th edition, VDMA, 2026 (wafer and cell market shares, module efficiencies for 2025)
- MNRE, Guidelines for PM-Surya Ghar: Muft Bijli Yojana (DCR rule, subsidy structure, module temperature coefficient specification)
- KERC order dated 25 August 2026 on tariff for distributed solar PV (module price benchmarks)
- TerraEnerG, “Raised vs Flush Mount with Bifacial Panels” case study, updated 27 October 2026
- MNRE rooftop solar FAQ (10 to 12 sq m of shadow-free area per kW)
Updated 5 November 2026. Technology and prices change; your final equipment and subsidy eligibility are confirmed after survey and at application.
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