In Conversation with Renkube: Harnessing the Potential of Solar Energy in India

India receives solar energy in abundance: approximately 5,000 trillion kWh annually over its land area. In most regions, the daily average solar energy received ranges from 4 to 7 kWh per square metre. There is, thus, great opportunity for harnessing solar power on a large scale in India. Yet, there remain great challenges to realising this potential.

To understand what these challenges are and talk about one novel way in which some of them can be solved, we sat down with Dr. Lakshmi Santhanam, COO and Co-Founder of Renkube Private Limited—a Biotechnology Ignition Grant (BIG) awardee revolutionising the solar energy sector in India through their Motion Free Optical Tracking (MFOT) technology for solar panels.

?How did Renkube come into being?

We were a group of engineers who had worked with each other in Cisco, and the idea for this start-up was formed over lunch table discussions. ?After several successful product launches at Cisco that won us the Pioneer Award, we were looking to replicate our success outside the corporate bubble.

Back in 2016, renewable energy was not the biggest thing, but we knew it was going to become a very promising field in the next decade given that we'll be running out of fossil fuels soon. And that's how we initially started with the idea of thermal energy. Like, “hey, we are living in India, it's a tropical sunshine country, can we do something to capture the sun better?”

Our first product was based on solar thermal technology. Unfortunately, it was not successful because the unit economics of the idea did not work out when we went into the details.

So then we thought, why not take the take the learnings from the failures in the solar thermal field, leverage our software background, and come up with an AI-based software that can churn out the best designs to capture sunlight?

What we have now built is a proprietary software with over 2,00,000 lines of code which can do just that. In a normal solar panel, the glass is flat, just like a cell phone. Using our AI-based software, we can create geometric patterns and designs on the glass to capture light in ways that increase the efficiency of the panel. Once the design is arrived at, the glass simply needs to be manufactured and assembled with the solar panels.

So that’s how we took, kind of, a cross-disciplinary approach. And after having spent so much time in this field, now we can proudly call ourselves experts in solar.

Can you tell us a little bit more about your team?

Definitely. I'll start with Balaji, who is the CEO. He was a Principal Engineer in Cisco and has 13 USPTO approved patents in the networking area. He also won three consecutive Pioneer Awards at Cisco.

And then myself, I come from a rich research and product building background. I worked at Cisco, Intel, and Qualcomm, on primarily new business initiatives. So, I was very excited when we were building something from the ground up at Renkube. Aside from design and development of the technology, I also take care of the operations at Renkube, executing the pilots, working with various stakeholders and manufacturers, and establishing joint ventures.

Our second Co-Founder is Deepika Gopal. She's also an ex-colleague from Cisco. She leads the development of smart optimising modules for monitoring our solar panels and takes care of the thermal analysis on the product side.

Dr. Janardhana Vittalrao Kshirsagar is our third Co-Founder. He and his team have helped us in the manufacturing of early prototypes.

Currently, it’s a small team working towards the commercialisation of the technology. We are looking to grow the team in the near future for our various pilot activities.

What makes your Motion Free Optical Tracking (MFOT) technology for solar panels unique?

We have designed a new type of geometry with glass that can bend the path of light to make it fall on the solar panel, thereby making the panel generate more units of electricity and become more efficient. The uniqueness of our solar panels is that once these light redirectors are fixed on the solar panels, they remain completely stationary. There is no adjusting or tilting needed, and yet it can track the sun throughout the year. Thus, the solution becomes a completely motion-free entity, which functions using only the principles of optics. Hence the name Motion Free Optical Tracking (MFOT).

Normally, the other way of tracking sunlight is through mechanical trackers which move the panel throughout the day following the sun’s movement from east to west. Mechanical trackers bump up the energy yield by 15% to 20%, but they also come with an additional capex of 10% and a need for continuous maintenance. The motors and gears come with a limited warranty of 7–10 years, after which they need to be replaced. Also, these trackers are applicable only in huge solar farms and are not viable for residential homes or commercial industrial units.

Our light redirecting prisms are assembled on the solar panels at the photovoltaic (PV) manufacturing unit, and then gets installed just like any other solar panel (for e.g., south facing with latitude tilt). There is zero movement/adjustment involved. There is no maintenance required like that in mechanical trackers, in tuning the actuators or sensors, and all that we need to do is to clean the solar panels like we clean them with water today.

How does your MFOT technology improve the price performance ratio of solar panels, and what benefits does it offer to solar panel manufacturers?

Today's solar panels are made via a certain process flow. There is a solar panel manufacturer who makes the panel, and then the installation personnel use motors and other electronic components to set up the solar tracking system.

We will be disrupting the tracking market. Now, a solar developer who wants the same performance as the tracker must simply procure Renkube panels from the manufacturers with whom we are tied up.

We have partnered with a Tier-1 manufacturer in Coimbatore, SWELECT Energy Systems, and to produce our custom designed panel, 95% of the process and procedures remain the same. ?It's just that now they need to fix these additional light redirecting prisms onto their panels. Once that is done, the Renkube panel is sent to the installation personnel.

The customer value proposition is tracker-like benefits with reduced capex. For example, a 100 MW solar project involving trackers has an additional capex of about $13 million for an extra 20% energy gain. However, Renkube’s MFOT technology offers the same benefit for an additional capex of $5 million with lesser maintenance overhead.

Also, customers will get back this additional capex within the next two years, because the panels are more efficient and can generate more units of electricity than the regular solar panels.

What are some of the biggest challenges you've faced while developing and commercialising your technology, and how have you overcome them?

Any DeepTech hardware product is capital intensive and time consuming to build. That was our first hurdle, and we were lucky to get support from various government grants like Nidhi Prayas, MSME Grants, and the BIRAC grant, which helped us improve our product. Actually, getting the support from government grants also had its own struggle in clearing the interview process and substantiating with sufficient paperwork. In fact, we applied and got rejected for the BIRAC grant for two years before finally receiving it in the third year. But, if I reflect on it, the government grants streamlined our data room, project reports, and milestone management, which was very useful during fund-raising later.

Another challenge has been in manufacturing our light redirecting prism for our pilot demonstration which is a small MoQ. We had to scout for glass manufacturers with a glass melting furnace and finally found a small cottage industry in Firozabad, Uttar Pradesh. We had also set up a small glass manufacturing lab in our office space. And finally, we overcame all the manufacturing issues to make our final MVP demo product. Our next step is to take this to large scale glass manufacturers to make it at scale.

Can you tell us more about your pilot in the AgTech sector, where you are exploring the use of solar panels in farmlands, in collaboration with Professor Jayashankar Telangana State Agricultural University (PJTSAU)? How did this collaboration come about?

The story with PJTSAU is definitely one of our success stories of cross-collaboration. We began our association with the university for the Agri-PV use case. Today, with traditional solar panels, you get a solid block of shadow underneath, right? This affects crop growth negatively and only shade tolerant plants can grow underneath solar panels. Our panels, due to their unique design, result in minimal shadow. We did some initial experiments, took flux measurements, and saw that more sunlight was coming underneath the Renkube panels. ?Our light redirecting prisms send the excess sunlight that is not required for the solar panel to the ground beneath the solar panel, and this can be very beneficial for the crop growth. In existing Agri-PV installations with traditional solar panels only 50% of the land is used for agricultural cultivation (primarily in the inter-row gaps of the panels). With Renkube panels, 100% of the land can be used for both solar and agriculture.

The first time I applied for the BIRAC grant, we had applied for a CleanTech project. The committee said that BIRAC is mainly focused around AgTech innovations, and suggested that we tie up with an agricultural scientific body. We pitched to about ten different universities before the sync with PJTSAU happened. The Vice Chancellor at PJTSAU, Dr. Praveen Rao, already had a vision to commission an Agri-PV plant at the university and was actively looking for a suitable solar developer. And we approached them at the right time with the right innovation. Hence, the synergies bloomed instantaneously.

There are about 20 Agri-PV projects pan-India, but it is only our Agri-PV project in Telangana which prioritises the free movement of tractors in the fields. ?Existing Agri-PV projects don’t allow farm machinery to be used, and crop cultivation with manual labourers becomes tedious work. So, we created this unique structural design so that there is minimal wastage of land, and 100% of the land can be used for both agriculture and solar panels.

And that's how our synergy happened. We now lend our expertise in terms of solar panel installation and energy measurements, and the University helps us with crop research.?

What are your plans for scaling up operations and expanding market reach in the coming years?

After our demonstration at PJTSAU, we got many inquiries from high income-group farmers with organic farms in and around Telangana. They are very excited about replicating this project in their own lands. In fact, it is not just farmers, we’ve got inquiries from reputed government bodies like the Indo German Energy F orum (IGEF) and Centre of Excellence for Horticulture Plants at Telangana, that want to adapt the project for flower crops and other fruit varieties.

In Bangalore, we recently met somebody at a renewable energy expo who had a vineyard and was interested in our product, as it is an elevated solar installation. We also have multiple inquiries for conducting pilots for commercial and industrial rooftop players.

We will be working now with our existing PV manufacturing partner whose manufacturing line can cater to our initial order book of 2 MW. We are also looking to partner with, as I said earlier, a large-scale glass manufacturer.

Post that, to roll out this technology on a megawatt scale, we would be working with multiple panel manufacturers. We also have an inquiry from an Australian company where they are looking to license this technology. So, we want to be the technology providers and scale this quickly. “Innovated, Designed and Made in India product” is the vision that we are looking to execute.

In India, there's a lot of push towards renewable energy, especially solar, because we have great capacity for harnessing solar energy. How do you see the overall renewable energy industry evolving in the next decade, and what role do you envision for Renkube in that future?

Today, India has accomplished the vision set in 2015 by producing cumulatively 166 GW of renewables, and we are marching towards tripling this to 500 GW by 2030. The demand for solar is further rising with the emergence of electric vehicles, green hydrogen technologies, and many other things coming up. With solar energy being used for the electrolysis process to produce green hydrogen, and solar carports that can charge electric vehicles, there is tremendous potential for its application. We are starting our journey with solar photovoltaics in the rooftop space. We'll slowly move to the utility space, and other solar areas. We want to become the technology providers who enable this motion-free technology on any surface exposed to the sun.

Let’s take the example of an urban home. I stay in an apartment; I cannot have a solar unit on the roof. But I can have it in my balcony. I currently don’t have one because a solar panel is not efficient when installed vertically in the balcony. Say you have an east facing balcony, you get sun for one half of the day, right? If we can develop a technology with affordable unit economics, and the payback is in three years to four years, then people will be ready to adopt it. So, we want to be that technology provider and take MFOT to solar balconies, solar windows, and solar walls.

Recently, we also got a grant from the US–India Endowment Fund, using which we are going to roll out MFOT technology for integrated roofs.

?Coming to the last question, how do you think BIRAC and IKP have supported you in your journey so far, and will they continue to be a part of your journey to fulfil your mission?

As I said before, we’re a DeepTech start-up. Before we had any investors on board, what allowed us to survive was the support via the BIRAC grant. Before BIRAC, of course, we had Nidhi Prayas and MSME grant. But these were all a smaller quantum of money through which we could only demonstrate a small working model. With the BIRAC grant, we were able to demonstrate our product on a scale that is acceptable to not only the scientific community but also to investors. The BIRAC funding also gives customers faith in our technology. Because when we say we are funded by BIRAC for this project, for example, people understand that it has undergone rigorous evaluation, and their trust factor just takes a quantum leap.

It's also a lot easier once we have the support of reputed incubators like IKP. When news of our product goes out through our incubation partners, it has a far greater reach among customers. When people see that it's coming from IKP, and they know that this incubator works with the top technology innovators in India, the end user has tremendous faith in the products.

Another form of support from IKP is their International Knowledge Millenium Conferences (IKMC) and other technology demonstration shows, where we get a lot of information on various events in the AgTech space. We also get the chance to interact with and put our technologies across to external stakeholders. This makes a huge difference for us in terms of meeting the right people at the right time. We look forward to the association with BIRAC and IKP to help us commercialise this technology in the coming years with further funds, technology licensing and mentorship. Finally, we would like to end by saying, “Solar is good, let’s makes it better!”