In a highly competitive solar industry where every cent counts, technologically advanced, cost-effective inverters that yield the maximum output is becoming the natural choice for solar installers.

While inverters account for only 5% of a project’s total cost, they are an important component in determining the performance and efficiency of a solar system.

String inverters accounted for nearly 49% of India’s total inverter market share in 2020, a steep increase from 30% in 2018.

According to the India Solar Market Leaderboard 2021, the string inverters category in the calendar year 2020 was ruled by Huawei, Sungrow, Growatt, Goodwe, and Solis.

With the rooftop solar segment also gaining momentum, string inverters are in great demand. Remote monitoring and in-built safety features are also integral parts of rooftop systems.

To discuss the various aspects related to string inverters and track their growth potential, Mercom held a webinar on May 31, 2021.

The panelists included Sudhir Pathak, Head of Design and Engineering, Hero Future Energies; Bhaskar Kamath, Rooftop Engineering, Tata Power Solar; Niranjan N. Naik, Bosch Energy, and Building Solutions; Shantanu Sirsath, Technical Head, Growatt; and Rakesh BP, Technical Sales Manager, Solis. The session was moderated by Priya Sanjay, Managing Director, Mercom India.

Optimizing the C&I segment

Speaking on the types of inverters being used by Tata Power Solar in their installations, Kamath said, “We are primarily into the C&I and residential segments. We stick to string inverters for most of our projects. String inverters cater to various sizes and ratings and are the best fit for both the C&I and the distributed ground-mounted segments.”

Speaking on similar lines, Pathak noted, “We deal with solar installations for the C&I segment and government buildings. For most of our projects, string inverters are in use. These are in the capacity range of 20 kW to 50 kW, with multiple maximum power point trackers (MPPTs). String inverters have several advantages and are ideal for rooftop projects, where space and access are pressing points. The market for string inverters is bound to grow in the coming years.”

Sirsath, on his part, added that while there are several kinds of string inverters in the market, choosing what fits a project depends on the applicability of the inverters.

“The main advantage of string inverters is that there is a variety in ratings, and we have inverters with ratings of 75 W, which can go up to 100-125 kW. These inverters are used for maximum output, and 99% of them are maintenance-free. Most of the inverters above 50 kW capacity come with fan cooling, and the maintenance cost is negligible. These factors make string inverters the ideal choice for the rooftop segment,” Sirsath added.

Brands hopeful of growth

Growatt and Solis are two of the top players in the solar inverter space.

“Growatt entered the Indian market nine years ago and has carved a niche for itself in this time. We have two service centers in the country, which makes after-sales service easily accessible for our clients. We have one service center in Hyderabad, and last year we opened another in Ahmedabad. We have sold nearly 150,000 units in India. The customers are familiar with our brand, and we hope to increase our presence in the string inverter market in the coming years,” Sirsath noted.

Speaking on the growth of Solis as a brand in the country, Rakesh said, “We entered the Indian market four years back and have created a market for our products. The most important thing in the business is to convey the right message, and we have done that. Now the consumers know that Solis is one of the leading players in the market. We have a network of service centers across the country, which makes it easy to win customer confidence.”

Selecting the right inverter

As string inverters grew exponentially in the past two years, it has become important to select the right inverters for the projects. There are several options available for the customers to choose from, and generally, it is the installers who choose on behalf of the consumers.

“String inverters are generally used for the rooftop segment now as they fit the bill perfectly. String inverters help reduce the levelized cost of energy to a great extent, while such inverters with optimizers are also used in projects where different modules with different outputs are used,” elaborated Rakesh.

“Selecting the right inverter depends on several factors. We deal with C&I customers and make them a comprehensive offer. Generally, they go with our choice and opt for string inverters as it helps in shadow mitigation and has a host of other advantages. One of the factors that go into choosing string inverters is the brand value. The brand plays a vital role in selecting the inverter. The after-sale service and operation and maintenance infrastructure are also integral deciding factors in picking up the right fit,” added Kamath.

“Generally, we are the ones who select the inverters for our customers. Ultimately, ‘it’s the supplier who persuades the customers in going for string inverters. Some of the factors that go into decision-making are the brand name, history of the company, after-sale service, and the research and development activities that go behind developing the products. The location of the project is also an important factor before opting for any inverter. For instance, keeping Delhi’s extreme climatic conditions in mind, installers should go for string inverters with multiple MPPTs, monitoring each string,” said Pathak.

“In most cases, ‘it’s the engineering, procurement, and construction companies that make their recommendations, and the customers go by it. Some clients come with technical specifications and choose accordingly. Keeping in mind the product quality is vital while making a choice. After-sale service, the record of the company, and the brand name are some of the other factors that customers look for,” added Naik.

Technological innovations

With rapidly changing technology, the solar inverter business is also evolving. Artificial intelligence (AI) is all set to capture the inverter market in the near future. AI and big data analytics are bound to make string inverters more intelligent and remote monitoring much easier.

“With growing awareness, the size of assets installed at a single location will grow, making the customers demand more from inverters. In the future, inverters with more technologically sound operations and greater use of big data analytics will lead the way. We will have inverters that could go up to the module level and check the efficiency of each module through drones. AI will play an important part going forward,” added Pathak, talking on the future course of the solar inverter segment.

“Right now, the diagnostic part of inverters is underutilized because full data is not available. Another important aspect that will be dealt with in the future is the reliability of string inverters. The efficiency can be increased by learning from previous failures, and the feedback loop will help develop better models. Reliability is very important and is key in designing future inverters,” noted Kamath.

Making a case for inverters with storage and AI, Naik said, “Inverters with battery storage systems will be the next big thing. Greater emphasis will be given to the safety of inverters, and AI and diagnostics are the way forward. String inverters with multiple MPPTs will dominate the market in the coming years.”

Inverter improvements, including greater granularity of MPPT, the amalgamation of artificial intelligence with more capable algorithms, are all set to usher in a new age of solar inverters that would be more capable of handling the changing demands of the solar industry.

You can watch the webinar here.