In an interview on the sidelines of the Mercom India Renewables Summit 2025, Kartikeya Narain Sharma, Co-founder and Chief Strategy Officer at Sunsure Energy, spoke about the future of open access projects and the evolving battery energy storage landscape.

Sharma spoke about the diminishing importance of plain solar and wind power projects, and the growing demand for hybrid projects and round-the-clock (RTC) projects.

Please give us an overview of Sunsure Energy                  

Sunsure is one of India’s most preferred renewable energy companies, a partner of choice for the commercial and industrial (C&I) sector. We have about 600 MW of operating assets and are building another 7.5 GW across solar, wind, and battery storage projects. Sunsure is all about enabling the deployment of massive amounts of RTC renewable energy. We want to play an important part in India’s mission of becoming energy independent.

What is the future of open access projects, and how do you see them evolving?

Open access has emerged as one of the primary means for industries to meet their renewable energy targets.

Renewable energy, so far, under open access has largely been solar. Over the last three years, we’ve seen an increasing preference towards a mix of solar and wind, enabling a more RTC and deeper offset of conventional energy sources with the use of solar and wind.

Moving forward, we see that the industries are now finding significant value in these solutions. With the evolving landscape in the states, industries prefer to rely less on regulatory benefits, such as banking, and move more towards real-time renewable energy power.

We will see a large battery storage installation in the next year. While most of them will come from utilities, I think a significant chunk will start coming from the industrial sector as well.

With the growing demand for energy storage and hybrid projects, what is the future of plain solar and wind projects in India?

I think there is a certain scale for which a plain solar or a plain wind open access solution makes perfect sense. For demands up to 5 MW, I think a plain solar or a plain wind solution works extremely well as it’s quick, straightforward, and not very capital-intensive.

For nearly flat power demands of more than 10 MW from industries such as data centers, steel factories, or cement plants, stable power from an RTC load is preferred. I think a mix of solar and wind is the way to go.

What is more ideal for the C&I segment — energy storage or RTC power?

I think there is a big overlap between RTC power and energy storage. Energy storage is a way of making your otherwise already RTC power from solar and wind even more dependable. You can use solar and wind alongside storage to ensure that you have power during your peak demand time — when the grid power is the most expensive, you can meet that demand if you’ve got storage in the mix.

On the other hand, if you’re using solar and wind with some amount of banked power, you can still make a sizable impact. As long as there is a certain amount of banking on the state network, I think battery storage will still be a niche in RTC offerings in intrastate open access. But as that fades away, battery storage is going to become a key component of RTC power.

What is the viability of adding a battery energy storage system to existing renewable projects in India?

I think it becomes increasingly attractive every year. This year, for example, we are seeing a new trend. States are finding that solar power is fulfilling a lot of daytime demand, which is cheaper, leading them to reduce daytime tariffs and increase evening peak time tariffs. What’s happening now is in a state like Maharashtra, you’re looking at a ₹5 (~$0.05) gap between daytime grid tariffs and evening grid tariffs.

As this gap grows, battery storage is viable and can help you store some power in the daytime and use it in the evening. As technology evolves and with the commercialization of battery technology across the globe, it will only become increasingly attractive. I think battery storage is going to feature in the C&I space, of course, in a big way in open access, RTC solutions, and in behind-the-meter applications.

How are different state regulatory frameworks impacting open access projects despite the issuance of green open access regulations in India?

The green energy open access rules by the centre are a very progressive step forward. Power is a concurrent subject in India. Every state has the freedom and the responsibility to implement that within its regulations to deliver the intended benefit to the stakeholders.

The green energy open access rules came out maybe three years ago. In the last three years, industrialized states like Maharashtra, Karnataka, Gujarat, Haryana, and Rajasthan have aligned their regulations with green energy open access rules.

When you’re initiating such landmark reforms in the power sector, you start with a policy, then you form a regulation, and then you eventually create procedures. It is at the procedural level that we believe there is room for improvement.

I think within the realms and constraints of all these industrialized states, the states have the intent to create and implement the green energy open access rules. But I think it’s a work in progress.

Are Distribution Companies (DISCOMs) pushing for energy storage by limiting banking facilities?

If you look at Rajasthan, they have just introduced a new regulation on open access mandating a 5% minimum battery storage for any new open access project. As you increase the size of your project, you increase the amount of energy storage required. This kind of regulation is the first of its kind. We are already seeing that on a utility scale, there are no tenders now without battery storage. Almost every tender requires you to do battery storage.

The panacea for DISCOMs mandating power banking is the installation of battery storage. It is a challenge in certain states. For example, in Maharashtra, you can install a battery storage to discharge certain power at a higher price during the peak hours, and the customers will still make a saving.

The shift towards battery storage is very real. But right now, you feel the tremors. But I think it is going to shake the entire ecosystem up in the next couple of years.

I’m very excited to see that, because it’s eventually going to make a truly win-win situation for independent power producers and developers, for end customers, and the DSICOMs.

Ultimately, you cannot disregard the fact that it is the distribution companies that have set up the infrastructure, which is the very rail of our industry. Hence, we need to make sure that it’s a win-win-win situation.

How do you address land acquisition challenges in solar parks?

The hardest part of developing a renewable energy asset, whether it is solar, wind, or battery storage, is getting the right kind of connectivity, voltage, and the resource region.

It means that you want to get as much renewable resource where you’re putting the plant as possible, and that you’re able to do the land in the right kind of time frame.

Today, for our 7.5 GW pipeline, our target is to acquire about 30,000 acres of land across seven different states in India. We have already acquired about 10,000 acres. We have another 20,000 acres to go.

Different states have different issues, but the way to address those issues is to have the right kind of people on the ground, working with the communities, over a longer period.

You have to accept that it takes time. You have to admit that if you’re going to do 30,000 acres, it probably happens over six years and not two years. It’s probably going to need a team that you can trust, and it’s going to need more than simply a commercial mindset.

You need to have a community developer mindset, and we achieve this by ensuring that we don’t focus on one project in one place.

Typically, once we figure out a state, we help the communities. The kind of development work we do in communities sets an example for the next project sites. Our investment in the project site enhances the community in terms of employment, development, education, and sanitation.

In simpler terms, for a renewable energy project, the key raw materials are connectivity and land. You can’t expect a very large customer to trust that you’re going to deliver a project. It’s the chicken before the egg, and the chicken is the connectivity and land acquisition.

What are the future expansion plans of Sunsure?

We take a very long-term view of the Indian energy sector. We believe that India’s demand growth, both industrial and non-industrial, is going to continue to grow at a massive pace. We are going to outpace the global power demand.

As a company meeting this demand, we want to be sure that we’ll be able to contribute meaningfully to our target customers and the country.

India has a 500 GW goal by 2030. We are hoping to set up close to 10 GW of power by then, as a mix of solar, wind, and battery storage.

Out of these 10 GW, we already have about 7.5 GW in place, identified with connectivity, land, and the raw materials. It’s a matter of now tying up the right kind of demand, and making sure these projects are delivered, and then on to the next decade.

(Note: Sections of the interview have been paraphrased for better reading. Check out the video for a full chat)