14-08-2026
The Devsol 740 W HDT module is a high-wattage heterojunction panel manufactured in India by Nexus Solar Energy Pvt Ltd. Heterojunction cells have the lowest temperature coefficient of any commercial silicon technology, around -0.24 to -0.26 %/°C, which is why HJT holds output better than TopCon or Mono PERC on hot Indian rooftops and ground mounts.
What is an HJT solar panel?
HJT - heterojunction, sometimes written SHJ, and sold by Devsol as HDT - puts thin layers of amorphous silicon on both faces of a crystalline silicon wafer. Those layers passivate the surface extremely well, which does three things: it lifts efficiency, it flattens the temperature response, and it very nearly removes light-induced degradation.
HJT is also bifacial by construction. The rear face is not an add-on; it is inherent to the cell design.
Why HJT suits Indian conditions specifically
| Behaviour | What it means on an Indian site |
|---|---|
| Temperature coefficient -0.24 to -0.26 %/°C | Holds output through May and June, when panels run 55-70°C and consumption peaks |
| About 5-6% loss at 45°C, against about 7-8% for TopCon | Roughly 2-3% more annual energy in hot climates |
| Degradation 0.25-0.30% a year | Around 89-92% of rated output still available at year 25 |
| Bifaciality 85-95% | Meaningful extra yield on ground mounts, elevated structures and light-coloured roofs |
| Near-zero light-induced degradation | No significant first-week output drop |
These are technology-level characteristics of heterojunction cells. For the figures that apply to the exact module you are quoted, ask for its datasheet.
Where a 740 W module helps, and where it does not
Helps: ground-mounted arrays, industrial sheds, elevated structures, and any site where you are paying for structure, cable and labour per module. Fewer, larger modules cut mounting hardware, string count and installation hours.
Does not help: small residential roofs with obstructions. A 740 W module is physically large and heavy. On a cut-up roof, a smaller module often fits more capacity than a bigger one does.
That is a sizing decision, not a brand decision, and any honest installer will tell you the same.
Certification
Devsol modules hold BIS registration R-93046086, issued 29 April 2026 and valid to 28 April 2028, under IS 14286 (Part 1/Sec 1):2023 / IEC 61215-1-1:2021 and IS/IEC 61730-1:2023 and IS/IEC 61730-2:2023, for crystalline silicon terrestrial PV modules. Covered models run Nex-200 to Nex-750 in the -IN0825 series.
Two things worth knowing as a buyer, whichever brand you end up with:
- A BIS licence covers named models, not a wattage range. Ask for the annexure and match the exact model code.
- If your project requires ALMM-listed modules, verify the specific model on the MNRE list before ordering. Check the model number, not the brand name.
The rest of the Devsol module range
Alongside the 740 W HDT module, the published Devsol range includes a 610 Wp TopCon glass-to-glass module, a 590 Wp TopCon 16BB module and a 590 Wp Mono 10BB module. Technology choice should follow the site: full technology comparison.
Questions to ask before buying any high-wattage panel
- What is the temperature coefficient of Pmax?
- What is the stated annual degradation, and the guaranteed output at year 25?
- Is the module bifacial, and does my mounting actually allow rear-side gain?
- What is the exact model code, and is it on the BIS annexure?
- What are the product and performance warranty terms, in writing?
Frequently asked questions
What is an HJT solar panel?
A heterojunction module: crystalline silicon with amorphous silicon layers on both faces. It has the lowest temperature coefficient of any commercial silicon technology and is bifacial by design.
Is HJT better than TopCon for Indian summers?
Yes on temperature behaviour. At around 45°C operating, HJT loses about 5-6% of rated output against about 7-8% for TopCon.
Does a bigger panel always mean a better system?
No. High-wattage modules reduce structure and labour on ground mounts and large roofs, but on small or obstructed roofs a smaller module often fits more total capacity.
Are Devsol panels BIS registered?
Yes. BIS registration R-93046086, valid to 28 April 2028, covering models Nex-200 to Nex-750 in the -IN0825 series.
Who manufactures Devsol panels?
Nexus Solar Energy Pvt Ltd, Chola Industrial Area, Bulandshahr, Uttar Pradesh.
See also: Devsol solar panel manufacturing and how to compare solar panel brands.