Manufacturing · Medak, Telangana

We start at the fin, not at the finished collector

Greentek is one of India's top five manufacturers of solar flat plate collectors — and one of very few that makes its own absorber fins. Fin, collector and tank are produced on one site in Telangana, to our own specification, under BIS licence.

In short: Greentek manufactures solar flat plate collectors, absorber fins and hot water storage tanks at its 30,000 sq ft factory in Telangana. Output runs to 20,000 absorber fins and the equivalent of 2,00,000 LPD of collector and tank capacity every month, BIS-licensed to IS 12933 under ISO 9001:2015 and ISO 14001:2015.

20,000Absorber fins / month
2,00,000LPD capacity / month
30,000sq ft factory
IS 12933BIS licence
1997Manufacturing since

Backward integration

What makes in-house fin manufacturing unusual?

The absorber fin is the part of a flat plate collector that actually captures heat — a selectively coated copper sheet bonded to the riser tube. Most Indian collector manufacturers buy fins in and assemble around them. Greentek makes the fin, which means the collector's efficiency, cost and lead time are governed by our own line rather than by a supplier's.

  1. Absorber fin

    Copper sheet, selectively coated, bonded to riser tube. 20,000 units/month. Nine fins make one 125 LPD collector.

  2. Collector

    Fins assembled into an aluminium-section box with rockwool insulation, toughened glazing and copper header — powder coated and pressure tested.

  3. Storage tank

    SS 304, TIG welded, PUF insulated, with a sacrificial anode as standard — and SS 316 vessels with immersed heat exchangers where the duty calls for it.

  4. Complete system

    Array, storage, hydraulics, controls and backup integration engineered and commissioned as one plant.

Because every stage sits inside the company, a large institutional order is a production schedule rather than a procurement risk — and a specification change (a different pressure rating, a non-standard tank, an SS 316 vessel) is a manufacturing instruction rather than a negotiation with a third party.

Exploded construction diagram of a Greentek solar flat plate collector, showing toughened glazing, selectively coated copper absorber with nine risers on a copper header, rockwool insulation and a powder-coated aluminium section box.
The collector, layer by layer. The absorber fin — the copper sheet under selective coating — is the part that actually captures the heat, and the part Greentek manufactures rather than buys.
Greentek flat plate collectors installed on a rooftop — three glazed FPC panels feeding two horizontal PUF-insulated storage tanks.
The finished article, installed — Greentek-built collectors and tanks on a terrace.

Plant & facilities

Where does Greentek manufacture?

Manufacturing

Telangana

A 30,000 sq ft factory at Shivampet Mandal, Medak district, running an automated production line for absorber fins, solar collectors and hot water storage tanks — the whole thermal chain on one site.

North India

Noida, Uttar Pradesh

Greentek Northern India Pvt Ltd, a subsidiary with warehousing, serving project delivery and dealer supply across the northern states.

Product specification

Greentek flat plate collector — technical specification

The Greentek FPC uses a selectively coated copper absorber of 1.9 m² with 96% solar absorptivity and 16% emissivity, nine copper risers at 110 mm spacing on a 25 mm header, rockwool insulation and 4 mm toughened glazing in a powder-coated aluminium box, rated to 3 kg/cm² working pressure.
Collector box
2025 × 1025 × 95 mm
Box material
Aluminium section, 1.4 mm
Bottom sheet
24 SWG
Finish
Powder coated
Insulation
Rockwool
Insulation thickness
50 mm base / 25 mm sides
Thermal conductivity
0.681 mW/cm·°C
Absorber material
Copper
Absorber area
1.9 m²
Selective coating
Nalsun
Solar absorptivity
96%
Emissivity
16%
Header tube
Copper, 25 mm dia
Riser tube
Copper, 12.5 mm dia
Risers / fins
9 at 110 mm spacing
Flange
Brass, 42 mm dia
Glazing
4 mm, transmissivity > 83%
Working pressure
3 kg/cm²

Grommets EPDM · rubber glass beading · stainless steel hardware. Manufactured under BIS licence to IS 12933.

Product specification

Evacuated tube collector — technical specification

Greentek ETC systems use double-walled borosilicate 3.3 tubes with a graded Cu/Al-N/AlN selective coating, holding vacuum below 5×10⁻³ Pa for absorptance above 92% and emittance under 8% at 80 °C. Available as integrated domestic systems from 100 to 500 LPD and as industrial modular arrays above that.
Tube material
Borosilicate 3.3 glass
Outer diameter
47 / 58 mm
Inner tube diameter
37 / 47 mm
Tube length
1500 / 1800 / 2100 mm
Glass thickness
1.6 mm
Selective coating
Graded Cu/Al-N/AlN
Vacuum
< 5 × 10⁻³ Pa
Absorptance (AM 1.5)
> 92%
Emittance at 80 °C
< 8%
Stagnation temperature
> 200 °C
Heat loss
< 0.8 W/m²
Maximum strength
0.8 MPa

Quality & approvals

How is quality controlled?

Manufacturing runs under ISO 9001:2015 and ISO 14001:2015 management systems, with collectors produced under BIS licence to IS 12933, the Indian Standard governing solar flat plate collectors. Greentek is registered with the MNRE, NEDCAP, NSIC and as an SSI unit.
  • BIS — IS 12933
  • ISO 9001:2015
  • ISO 14001:2015
  • MNRE registered
  • NEDCAP registered
  • NSIC registered
  • SSI registered

Pressure testing

Collectors are pressure tested against the 3 kg/cm² working rating before despatch; tanks are tested to their design rating.

Coating verification

Selective coating checked for absorptivity and emissivity — the two numbers that determine whether a collector performs as specified in year five, not just year one.

Traceability

Batch records tie a delivered collector back to its production run, which is what makes matching spares possible a decade after commissioning.

OEM & trade supply

Supplying other manufacturers, EPCs and dealers

Greentek sells components, not only finished systems. Absorber fins go to other collector manufacturers; bare collectors and tanks go to EPC contractors and dealers, on Greentek specification or built to a customer's drawing.

20,000 / month

Absorber fins

Selectively coated copper fins supplied loose. Nine fins per 125 LPD collector — roughly 2,200 collectors' worth of fin output every month.

Built to spec

Bare collectors

Complete FPC units for integrators to brand and install, or manufactured to a customer's own drawing and specification.

Standard & custom

Tanks & pressure vessels

SS 304 TIG-welded and PUF-insulated storage as standard; SS 316, horizontal cylindrical vessels with manholes, and tanks with immersed heat exchangers to order.

Talk to the plant, not a reseller

Component enquiries, OEM supply, tender documentation and certificates — straight from the manufacturer.

Enquire about supplySee complete systems