New IECC research shows solar power with battery storage can deliver round-the-clock renewable electricity in India at Rs 5.15 per unit, undercutting SECI’s latest RTC auction tariff and rivaling new coal power costs.
Combining photovoltaic generation with energy storage systems can produce reliable 24-hour green electricity at a projected rate of Rs 5.15 per kilowatt-hour, according to research from the India Energy and Climate Centre at the University of California, Berkeley. This calculated figure falls under the Rs 5.25 to Rs 5.26 per unit tariffs established during a recent 1,000-megawatt procurement run by the Solar Energy Corporation of India.
The research, which examined ten years of hourly meteorological information across ten Indian states, showed that a facility combining 3 gigawatts of solar generation capacity with 12 gigawatt-hours of battery storage can satisfy supply requirements in Rajasthan. The competitive tender designed by the state agency requires participants to emulate traditional base-load generation by delivering higher energy levels during morning, evening, and nighttime periods while tapering output during peak mid-day sunshine hours.
Under the specific terms of the solicitation, power suppliers must provide a minimum of 90 percent of contracted energy during six designated peak hours selected by buyers, 70 percent during remaining off-peak non-solar hours, and 50 to 60 percent during peak daylight times. Performance is evaluated at 15-minute intervals, with non-compliance penalised at 1.5 times the agreed contract rate. Expanding the project scale to 3.5 gigawatts of solar capacity alongside 12 gigawatt-hours of battery storage would fully prevent financial penalties over the decade-long dataset at an estimated rate of Rs 5.28 per unit.
The most economical design yielded a cost of Rs 5.15 per unit, with penalty fees representing roughly 0.5 percent of overall earnings. Regional atmospheric conditions in northwestern areas like Jammu and Kashmir, Rajasthan, and Gujarat allow developers to fulfill yearly output requirements using a 3-gigawatt solar and 12-gigawatt-hour storage setup, whereas other regions would need roughly 3.5 gigawatts of solar array capacity to meet identical benchmarks.
Umed Paliwal, director of modeling and analytics at the research center and principal author of the report, noted that the nation's consistent annual solar conditions make it ideally suited for electrochemical storage. He explained that the primary technical goal involves transferring excess daytime generation to meet late-day and overnight consumption demands using established, cost-effective battery technology.
The underlying public auction drew participation from 16 commercial entities, resulting in capacity allocations for seven winning bidders at rates spanning Rs 5.25 to Rs 5.26 per unit. Santosh Sarangi, secretary in the Union Ministry of New and Renewable Energy, remarked at a recent sector event that the bidding process proved solar-plus-storage projects can deliver dependable power at viable market prices despite initial assumptions that rates would run higher.
Nikit Abhyankar, co-faculty director at the research center and co-author of the paper, highlighted that the tight margin among winning bids indicates the Rs 5.25 result represents a consistent price point. The study further noted that seven long-term coal power purchase agreements executed in 2025 featured starting rates between Rs 5.38 and Rs 6.30 per unit, whereas the recent renewable energy contracts maintain a locked price of Rs 5.25 per unit across a 25-year operational lifetime.
Originally reported by Down To Earth on Aug 20, 2026.
