Signify Innovations India Ltd (formerly Philips Lighting) and Okaya Power Group have emerged as frontrunners for an estimated $28 billion order to supply solar home systems, said two people aware of the development.

Billed as the world’s largest such tender, Croatia’s Solvis d.o.o. and New Delhi-based Gautam Solar Pvt. Ltd have also submitted bids to state-run Energy Efficiency Services Ltd (EESL) for supplying as many as 47 million home power systems.

EESL—a joint venture between NTPC Ltd, Rural Electrification Corp. Ltd, Power Finance Corp. Ltd and Power Grid Corp. of India Ltd—is conducting the price discovery exercise for the member nations of the International Solar Alliance (ISA). The first phase will be for 9.3 million home power systems—each comprising a solar panel, battery, LED bulbs, fan and charging ports for radio, TV and USB.

“A total of four bids had come, in which Philips and Okaya Power are the frontrunners. The technical evaluation is going on,” one of the two people cited above said, asking not to be named.

EESL would seek to replicate a price discovery exercise it had conducted earlier by aggregating demand from ISA member nations for solar-powered agricultural pumps. This led to the prices of such pumps falling by half. Tenders such as these are also expected to attract global manufacturers that are exploring a China-plus-one strategy for production.

The price discovered from the solar home system tendering process will be offered to all ISA member nations for acceptance and serve as the reference point for such large global orders.

An EESL spokesperson confirmed in an emailed response the bids from Signify Innovations India, Solvis, Gautam Solar and Okaya Power.

“Details of these kinds of tenders are confidential. Therefore, we can neither confirm nor deny that we’re part of this tender. For any information of this process, we suggest you follow up with EESL,” a Signify Innovations India spokesperson said in an emailed response to a query.

An external spokesperson for Okaya declined to comment.

“EESL is helping us finalise the bid,” an ISA spokesperson said in an emailed response.

Solvis and Gautam Solar couldn’t be contacted.