Higher Generation and Lower Landed Cost Make Floating Solar Appealing: Interview

The cost difference between floating and ground-mounted solar is offset by savings in O&M


To achieve India’s national targets for solar capacity additions, alternatives such as the floating solar need to be explored and established, considering their lower levelized cost of electricity and operation and maintenance costs, which is further complemented by easier deployment, Deepak Ushadevi – MD & CEO – Ciel & Terre India, said in an interview on the sidelines of the Mercom India Renewables Summit 2023.

Here are excerpts from the interview.

What is the driving factor for adopting floating solar solutions?

Traditional roof and ground mount utility projects face land scarcity issues, leading to wind and floating solar as new alternatives that reduce carbon footprint and offer solutions.

The challenge is to preserve land and minimize delays in acquiring it for organizations and infrastructure development. So, we need to explore new solutions, including tapping into the potential of floating solar in inland water bodies.

It allows us to install solar panels over water, preserving land and water while being an excellent alternative replacement for traditional solar panels from social, economic, and biological perspectives.

The extra 5-7% generation from floating solar due to panel cooling also reduces the Levelized Cost of Electricity (LCOE).

In India, many dams and reservoirs have great potential for floating solar. In recent years, the maximum capacity of floating solar projects has increased from 2 MW to 500 MW.

Currently, 2 GW of floating solar tenders are already auctioned, and we expect to see 2-3 GW of floating projects in India in the next 2-3 years.

Globally, in the next three years, over 77% of the floating projects, equivalent to around 11.50 GW, will occur in Asia, particularly in the Indian subcontinent and Southeast Asia.

How do companies identify states with inland water bodies suitable for floating solar projects?

We do not face any issues with water bodies in India. According to data, we have 5,534 available dams and reservoirs.

Even if we use only 40% to 50% of them, we can generate over 200 GW of power from these projects. In addition, we have backwaters and both manual and non-manual reservoirs, providing us with plenty of options. We can optimize capacity utilization by considering dams and reservoirs for floating solar and natural hydropower.

The existing infrastructure for dams with power infrastructure available eliminates the need for additional power infrastructures.

We can use the dams and reservoirs as they are, and there is no need for road filling, approach ways, or other ground modes.

A hybrid model combining floating solar and natural hydropower can be used, where floating solar can be used during the day and hydropower at night. This way, we consider both sources and use optimized operational ways to complement each other.

What are the cost savings and efficiency gains with floating solar projects?

Looking at it from a cross-functional perspective, ground-mounted solar structures require the use of purlins and rafters, along with piling work.

On the other hand, we need to use anchoring, mooring, and hearing anchors for floating solar projects to withstand high winds, depths, waves, currents, water level variations, droughts, floods, and more.

It is the most expensive part of the project. However, we also get extra generation capacity over 25 years, which offsets the additional cost.

As a company with a globally recognized portfolio of over 300 projects completed in 32 countries across five continents, with a 1.7 GW portfolio, we are experts in the field.

Delay in land acquisition is a major issue nowadays, but the government owns water bodies, so there are no issues related to land acquisition.

In addition, we use only 4 to 5% of the water reserves, minimizing any impact. We also conduct detailed studies to ensure that flora and fauna are unaffected and fishermen’s activities are not hindered. Fish breeding is more effective under the cooling effects of floating solar structures.

Which states are at the forefront of exploring floating solar solutions?

RUMSL, a part of the Madhya Pradesh government, has awarded a 600 MW project. Phase one is in Omkareshwar.

Odisha and Kerala have also tendered 2-3 projects each. NTPC has put forward more than 300 projects, including a 1 GW project in Damodar Valley Corporation (DVC).

Initially, there were questions, apprehensions, and teething issues regarding who will take care of the first project.

However, the project has started, more tenders are being issued, and stakeholders feel confident that this is a viable alternative.

Most state governments are asking us about the feasibility and possibility of the project, with some already in the tendering stage.

Could you tell us about the average cost of power for floating solar projects?

The average power cost is around ₹3.15 (~$0.038)/kWh – ₹3.3 (~$0.040)/kWh, which is the PPA (power purchase agreement) signing-off rate.

However, some variations may be based on the availability of modules, BCD (Basic Customs Duty), ALMM (Approved List of Models and Manufacturers), and other factors that affect transactions and cause minor delays.

The cost difference between ground-mounted and floating structures is only 7 to 10%, with the latter being slightly more expensive due to its technology. However, over time, the cost difference will be offset by savings in operation and maintenance costs.

Currently, the availability of modules is a major concern, with more than 60% of them being imported and the BOS part accounting for around 75 to 80% of the overall cost. However, even with these factors, the power cost of ₹3.15 (~$0.038)/ kWh is still considered reasonable by many states.

Additionally, selling excess energy at a rate of ₹5 (~$0.061)/kWh can help offset the cost of power bought at a lower rate. Over the years, the power cost has decreased from around ₹4 (~$0.049)/kWh to the current rate.

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