GREW Solar has signed a five-year partnership with California-based Caelux Corporation to produce 4 gigawatts of hybrid-tandem solar modules, with commercial production targeted for 2028. The agreement will combine Caelux’s perovskite technology with GREW’s n-type TOPCon solar technology for modules designed to achieve efficiencies of more than 29 per cent.
The partnership, announced on Wednesday, will use Caelux’s energy-producing glass as a second generation layer above the silicon cell. GREW said the technology will be incorporated into its large-format G12R series and other hybrid-tandem modules. The companies are targeting modules that meet the eligibility requirements of India’s Approved List of Module Manufacturers, or ALMM.
Hybrid-tandem modules generate electricity through two energy-producing layers rather than relying only on a conventional silicon layer. According to Caelux, its proprietary technology converts the top glass of a solar module into an additional power-generating surface. The company says this can increase energy density by up to 30 per cent and improve the levelised cost of electricity by 20 per cent or more.
The planned production is part of Caelux’s wider commercialisation pipeline. The company said its contracted volume with solar module manufacturers globally will reach 19 GW after the GREW agreement. The partnership therefore links an Indian manufacturer’s expansion plans with a technology platform that is being positioned for higher-output solar generation.
GREW currently operates a 6.5 GW solar photovoltaic module manufacturing facility in Dudu, Rajasthan. The company plans to increase its module manufacturing capacity to 11 GW. It is also establishing an 8 GW solar photovoltaic cell manufacturing facility in Narmadapuram, Madhya Pradesh, while its 8 GW wafer and ingot production lines are under construction.
These facilities place the partnership within a broader expansion of GREW’s manufacturing chain. The company’s stated plans cover modules, cells, wafers and ingots, while the Caelux agreement focuses on adding a second energy-producing layer to the module itself. The production target for 2028 means the commercial availability of the hybrid-tandem modules remains a future milestone rather than an immediate change in the company’s current output.
The ALMM requirement is significant for the proposed Indian production. Modules included on the approved list are eligible for use in projects covered by the relevant government procurement and support framework. The companies have said the planned advanced perovskite-plus-silicon modules will meet those eligibility requirements, but the announcement does not provide details on the approval process, investment value, plant location or the expected annual production schedule within the 4 GW agreement.
For India’s solar manufacturing ecosystem, the announcement brings together domestic capacity expansion and a technology aimed at producing more electricity from the same module footprint. The available details do not establish how the modules will be priced, when pilot production will begin or how quickly they will be deployed in operating solar projects.
The next stated milestone is commercial production in 2028. Until then, the partnership’s progress will depend on the development and manufacturing of the perovskite-plus-silicon modules and their compliance with ALMM eligibility requirements.
