Can round-the-clock renewables become India’s new baseload? A look at REMC, SECI and the RTC 3.0 model

India’s clean energy transition is moving into a new phase, and it is no longer just about adding more solar or wind capacity. The next big question is whether renewable energy can replace coal as a dependable, all-day power source. This challenge goes beyond generation and enters the realm of availability, scheduling, grid stability, and storage. The answer lies in a fast-emerging category: round-the-clock, or RTC, renewables.

Round-the-clock power supply from renewables aims to deliver dispatchable electricity every hour of the day, using a portfolio of solar, wind, and energy storage. It is a model that demands performance, not just capacity. While traditional renewable energy projects contributed green megawatts, RTC projects aim to replace fossil fuel baseload by offering firm power on par with thermal stations. India’s efforts in this space are being shaped by institutions like the Solar Energy Corporation of India Limited and REMC Limited, both of which have introduced structured tenders to make RTC viable at scale.

This article explores how the RTC model is evolving, why SECI and REMC are at the center of it, and what India’s energy sector must overcome to turn renewable power into the country’s next baseload.

How round-the-clock renewables are redefining the energy supply model in India

The concept of round-the-clock renewables challenges the earlier perception that clean energy cannot meet demand beyond daylight hours or wind peaks. In practice, RTC projects combine different clean energy technologies, typically solar and wind, and use energy storage systems to fill in the gaps. The result is a dispatchable power product that can be scheduled in advance and delivered 24/7 to utilities or commercial buyers.

What sets this model apart is its focus on hourly availability rather than annual averages. In India, where power distribution companies are under pressure to manage demand curves and maintain reliability, RTC offers a way to buy renewable energy without sacrificing stability. Developers, however, must commit to meeting strict availability thresholds. For instance, REMC Limited’s 2025 tender required minimum availability of 75 percent in the first three years, rising to 85 percent thereafter, and time-block-wise availability of 50 percent across all 15-minute intervals.

This new framework shifts the burden of firming and integration from the grid to the developer. It also opens up a new class of power contracts that resemble baseload procurement in structure, tenure, and performance expectation.

How SECI and REMC tenders are driving India’s RTC 3.0 shift

The first round of RTC procurement in India began with Solar Energy Corporation of India Limited, which floated the earliest utility-scale tenders requiring developers to offer dispatchable clean energy. A landmark 400 megawatt RTC tender by SECI in 2020 set the ball rolling, with bids touching tariff levels of ₹2.90 per kilowatt hour. These tenders introduced the idea that hybrid and storage-backed renewables could be sold not just as energy, but as a firm service.

In 2025, REMC Limited raised the bar with its 1,000 megawatt RTC tender for Indian Railways’ traction load. The REMC Limited tender required developers to provide consistent, grid-connected renewable power, either with or without storage, under a 25-year power purchase agreement. Winning bidders, such as Ayana Renewable Power Private Limited backed by NTPC Green Energy Limited and ONGC Green Limited, had to meet time-block availability and maintain robust scheduling through e-reverse auction-based contracts.

What distinguishes this phase, often referred to as RTC 3.0, is the institutional maturity of the procurement process. Tenders are now aligned with real-time grid demands, and the buyers, such as Indian Railways or large state distribution companies, expect baseload-style delivery. These projects are long-tenor, performance-linked, and increasingly bankable.

Why RTC renewables are being seen as a potential replacement for coal baseload

India has historically relied on coal to provide reliable, 24-hour electricity to its industrial and residential load centers. Coal plants offer dispatchable capacity, which is why they have remained central to power planning. However, as the environmental costs and fuel logistics of coal become increasingly problematic, clean energy backed by storage offers a path forward.

Multiple studies have confirmed the feasibility of RTC-based clean energy. The National Renewable Energy Laboratory’s India Renewable Integration Study showed that the Indian grid can absorb over 100 gigawatts of solar and 60 gigawatts of wind power while maintaining system stability, even without significant investment in peaking plants. It also demonstrated that coal plants can provide enough flexibility to integrate higher renewable shares, provided grid codes and transmission plans are upgraded.

More recently, TransitionZero projected that India could deploy more than 50 gigawatts of RTC clean electricity by 2030 using cost-competitive portfolios. Their models estimate that such a shift could reduce power system costs by nearly ₹9,000 crore annually while enhancing reliability.

These findings reinforce the view that with the right planning, RTC renewables can serve as baseload in key parts of the Indian power system. But execution risks and financial viability remain.

What risks and structural challenges must be overcome to scale RTC projects?

Despite strong policy momentum, the path to RTC-as-baseload is not without friction. One major constraint is the cost of long-duration energy storage. Lithium-ion batteries, while cost-effective for 1–4 hour storage windows, become economically challenging when stretched beyond that. This forces developers to either overbuild capacity or integrate multiple technologies, such as solar during the day and wind at night, to meet availability targets.

Another challenge is transmission readiness. Many of the regions rich in renewable resources do not have the interstate transmission infrastructure to support round-the-clock delivery, particularly across multiple states or load centers. Even where capacity exists, curtailment risks due to grid congestion or weather variability create added uncertainty.

From a procurement standpoint, contract design is evolving, but financial institutions still require risk buffers before funding large RTC projects. Performance guarantees, grid connectivity, and payment security from state utilities remain areas of concern. Developers also face higher capital expenditure upfront, given the hybrid nature of these projects and the need to invest in forecasting, control systems, and availability-linked maintenance.

Until these issues are addressed systematically, RTC projects will likely remain limited to top-tier developers and high-credit buyers.

Why institutional investors and power buyers are leaning into RTC tenders

For power buyers, especially those with high load factors or regulatory clean energy obligations, RTC contracts offer a compelling alternative to conventional power. They guarantee a fixed tariff over a long period, ensure green compliance, and reduce exposure to fossil fuel volatility. Indian Railways, for instance, has used REMC Limited tenders to lock in RTC clean power for its traction operations in multiple states, supporting its 2030 net-zero goals.

From an investor standpoint, RTC projects are evolving into infrastructure-grade assets. With long-term power purchase agreements and regulated offtakers, they offer annuity-like returns. Several developers are also exploring asset monetization routes through green bonds or infrastructure investment trusts, unlocking liquidity for capital-intensive hybrid portfolios.

This shift is also prompting a reconfiguration of the developer landscape. Players capable of integrating solar, wind, and storage at scale such as Ayana Renewable Power Private Limited, ReNew Power, and JSW Energy are pulling ahead in RTC auctions. Mid-tier developers with limited access to capital or system integration capabilities are struggling to compete on tariff and bankability metrics.

The segmentation of the market based on execution capacity, storage access, and grid visibility is likely to accelerate in the coming years.

Can RTC power fully displace coal as India’s baseload in the coming decade?

The long-term view suggests it is possible, but not yet probable without major enabling reforms. RTC renewables will need policy support in the form of storage subsidies, transmission buildouts, and clearer market mechanisms for capacity and ancillary services. The Central Electricity Authority has begun planning for a 500 gigawatt non-fossil capacity target by 2030, of which a meaningful share is expected to come from RTC-type assets.

What happens next will depend on how quickly cost curves decline for energy storage, how regulatory frameworks evolve for hourly scheduling and deviation settlement, and whether state utilities commit to RTC procurement over legacy thermal contracts. In parallel, India’s ability to monetize these projects through infrastructure funds will shape how much capital flows into RTC development.

For now, RTC remains a fast-expanding niche. But with the right market signals, it could become the spine of India’s power system, replacing coal as the backbone of reliable supply in an increasingly electrified economy.