Central Electronics Limited (CEL), a public sector enterprise, has invited online technical and financial bids from eligible bidders for the supply of 1 ton of solar photovoltaic (PV) ribbons.

Solar ribbons are copper conductors installed in solar PV panels. These ribbons play an important role in determining the solar cell’s efficiency as they carry the current generated in the solar cell to the PV bus bar.

The date of opening of the bids has been set for May 4, 2020.  The tender stated that the bids submitted by the supplier would be valid for a minimum period of 90 days from this date.

CEL stated that the ribbons must be 5 mm in width and 0.3 mm in thickness with a base material of high conductive annealed ETP copper ~99.90 Cu. The resistance of the PV ribbon must not be more than 15 ohm/km at 20 degrees Celsius. The coating must consist of 60% tin and 40% lead on each side of the strip and must be at least 15-20 microns thick.

The photovoltaics manufacturer also specified that the ribbons must be packed in 5 kg 10-S spools and that the spools should be shrink-wrapped or vacuum-packed into cardboard boxes with EP foam inserts. The ribbons must be smooth and uniform, and any branches or streaks of exposed copper are not acceptable.

It stated that only original equipment manufacturers (OEMs) are allowed to submit quotations, along with their authorized representatives. Vendors who are technically qualified but are unapproved are expected to provide 5 kg samples of PV ribbon that meet CEL specifications for approval.

The ribbons will also go through a testing process, as per the tender documents. Solderability and uniformity of the tin-lead coating must be checked for approved vendors. The material must withstand a minimum of 10 bends before failure or breakage. Reels that do not meet the quality standards will be rejected. Samples provided by unapproved vendors will also be put through the same testing process. Upon clearance, the vendor will be marked as an approved supplier of PV ribbon, and following this, CEL’s purchase department will place an order for the remainder of the quantity.

CEL has provided two payment options. The first option allowed for payment within 45 days from the consignment note. The second option states that suppliers could provide a letter of credit that can be encashed within 45 days of the consignment date.

Previously, Mercom reported that Central Electronics Limited floated a tender for 3 MW of multicrystalline solar modules. Each of these modules must be rated for a minimum of 325 Watts peak (Wp) with 72 cells. The bidder will be responsible for the design, manufacture, assembly, testing, and supply of solar PV modules.

Recently, CEL also issued a tender for a 535 kW grid-connected solar project at the National Institute of Biotic Stresses Management (NIBSM) Campus at Baronda in the Raipur district of Chhattisgarh.

Earlier, the government of India invited an expression of interest (EoI) for the proposed disinvestment of 100% shareholding in Central Electronics Limited.