As Inverters Become ‘Smart’ Customers Follow Suit

Solar inverters, with a share of 3-7% of project cost typically, have always played a far more critical role than the share of costs would imply. As the ‘brains’ behind the plant, the role of the inverter in converting power generated with the highest possible efficiency, in the safest way possible, has been critical for solar plants. Add to that the dominance of foreign brand names, and customers in India were happy to leave the decision to their EPC or installer.

An exception was perhaps made for brands like Enphase, which dominates the micro-inverter space, and comes at such a significant premium that a customer is virtually forced to look up and take notice to understand the reasons why.

But now, with rooftop solar in both residential and C&I segments picking pace, besides larger utility scale deals in the C&I as well as grid level plants, there has been a perceptible change at the customer end. For Sanjeev Jain, a businessman in Delhi who is evaluating the possibility of a 20 kW solar system to meet his energy needs at his farmhouse near the city, the research is certainly much needed. “At the end of the day, a solar system, whatever be the make of the components, is a high fire risk, if not built right. That makes the quality and background of the builder (installer) as well as components used critical to me”, he asserts. Jain has evaluated the firms his installer/EPC recommended by checking their websites, and seeking references from other industry players.

It’s a view that is increasingly shared by many others, including even discom inspectors who approve the solar plants for final grid integration. One such BSES inspector we spoke to claimed that he has regularly told buyers to consider switching, or taking extra precautions in case they opt for what he considers ‘low quality’ inverters. “We have to certify these systems as fit and ready for activation, and by now, we have also collected enough feedback on where and possibly what brands cause problems”. His name cannot be disclosed as he is not authorised to speak to media.

Having evolved over time in all aspects- output, efficiency, safety, resilience, adaptability, technology. Innovation too has propelled the market forward in an unprecedented way as Central (for Utility scale), string, hybrid, storage, microinverters- today’s highly-aware customer, is spoilt for choice and has an answer to all of his needs and applications. Tapping into the potential and opportunity that the market offers, an increasing number of players in the market are also coming up with inverter solutions that cater basis inverter type, size, application and system. No wonder then that the solar inverter landscape, therefore has become highly advanced, innovative and competitive today.

In 2021, the Indian solar inverter market stood at USD 4.20 billion in 2021. In the next six years, the solar inverter market is set to grow at a CAGR of over 30%, with inverters typically being replaced twice or more during the lifetime of a 25 year solar plant.

Some of the solar inverter players that ruled the Indian market in 2022 are China based global majors like Sungrow, Solis India, Goodwe, Growatt, Sineng, besides other global majors like Fimer. The good news is some Indian brands have also started getting visibility, with brands like Pyramid, Invergy and more seeking a higher market share. Filling in niche spaces with specialised offerings are Solaredge and Enphase, to name two.

Mapping The New Customer

Idris Khan, Chief Technical Officer, Solis India, informs us that as per Solis India market research for customers, and from the research reports, the firm finds that the factors that customers care about most when looking for a solar inverter are “price and production capability.” He continues, “Other factors that influence client decision, from our point of view, is brand. Established in 2005, Solis India Technologies today has one of the widest installed base of string inverters globally. The reliability of our products has been tested for a long time and across regions around the world. Our No.3 PV position in global inverter ranks by IHS Markit reflects the recognition of our brand by customers all over the world.”

Another industry veteran we spoke to told us about how firms were still adjusting to the new reality of more direct customer communications. “ As solar spreads, information is no longer the domain of installers, or EPC’s. Whether it is PSUs with their mandate for large utility scale solar capacity, or firms adding renewable energy to their energy mix, or even households seeking solar power, the end buyer has learnt with experience, or is seeking more information.”

Factors that customer looks out for & bank on

Not surprisingly, after-sales service has emerged as a significant factor that leads to customer satisfaction, greater customer-brand relationship and perhaps most importantly, positive word of mouth.  More and more solar inverter players have recognised this fact and are working to ensure they have a satisfactory after-sales services in place.

Idris Khan, sheds light on what makes Solis India a preferred choice for customers, “ After sales has always been a priority for us at Solis India India, as we appreciate the value, and importance of uninterrupted energy for our customers. We have a strong after-sales team to achieve “timely, efficient, high quality, worry-free” service for each of customers globally.”

As per Sandeep Goyal, CEO & Founder, Pyramid Electronics, warranty and efficiency are the most important factors that customer bank on while buying inverters. “Most efficient inverters may be 10-15 % more priced but this price difference will be negligible in context of life span of solar power plant,” he concludes.

A hybrid inverter, though  more efficient, is more costly than an on-grid inverter. The hybrid inverter can operate from solar panels, utility grid, and solar batteries all the same time, which makes them more efficient. However, a hybrid inverter may or may not need batteries to work.

Idris Khan has a suggestion to offer here when choosing a solar inverter, “The product needs to have technical features that are easy to install and maintain. Solis India products could help the owner save a lot of time in installation and management of the power plant.” It’s a key point we will come to, as you will see.

Sandeep Goyal further underlines the importance of after sales support. Pyramid offers unconditional warranty on inverters irrespective of reason of faults.

Sreenivasa M, Manager Sales, Sungrow, which emerged as the global leader in 2022, has advice both for solar installers  and buyers, “One needs to be familiar with the design concepts & limitations on the specifications before designing the system. Companies like us have introduced new technology & features which help the EPC or the developer to optimize the BOS cost, monitor the generation through our monitoring portals and also identify the type of issue in case of breakdown and troubleshooting the inverter.. Choosing the inverter model depends on the type of project and terrain of the plant and other various factors by the EPC or the developer.”

When it comes to market segments, higher BOS costs are incurred by residential solar systems vis-à-vis commercial installations of larger size. The costs are even higher for complicated arrangements such as canal-top and floating PV systems. Meanwhile, BOS costs for utility-scale systems are much lower due to economies of scale.

However, one aspect that both customers, and to an extent the inverter makers themselves need to pay attention to, is the nature of after sales support. As the market expands with more and more first time buyers, customers need to realise that a lot of after sales support might be in the form of online or phone sales support. For many end users, that can be a challenge, as they are unfamiliar with the jargon used, or simply expect a service engineer to drop by. It’s definitely a   challenge for the firms involved too, as a high closure rate on phone/online means real cost savings, and faster resolution in most cases. Most are therefore investing more into training internally, besides trying to make the key maintainance aspects as simple as possible for their customers.

For large utility scale customers who usually outsource O&M to competent firms, the relationship of the vendor with multiple parts suppliers matters, as does the nature of the warranty itself.

No matter how smart today’s generation of solar inverters are, they have their share of vulnerabilities. For instance, they may confront the challenge of overheating, or may not even be installed appropriately in the first place. Other factors such as humidity also affect their maintenance. Some even stick to the solar 133% rule for solar inverters, meaning a solar inverter can oversize a solar power system by 133%.

They are also susceptible to failures due to grid failures- high or low voltage.

This means firms like  Bengaluru-based Sanchay New Age Developers, that install inverters, have come up with a zero-profit model to offer free solar aftersales service. Further, they have limited their on-site servicing and/or troubleshooting time to a two to 24-hour window. This is available to the customer who have access to their CapEx model. This response within hours, right upto complete replacement if needed within 72 hours, is becoming the industry standard today.

Idris Khan, CTO, Solis India establishes how O&M, which includes both installation as well as after-sales service provided by installers and developers are important to cement the reputation of an inverter brand, “Even as  it converts direct current of the PV modules into grid-compliant alternating current and feeds this into the public grid, it controls and monitors the entire plant to ensure maximum power and safe running. According to him, The core elements of inverter selection can be considered from 4 important dimensions: the brand, technology, easy O&M and service.”

While many a time, from the developer/ installer end, complicated and time-taking troubleshooting, or faulty designs or improper installation are to be blamed for inverter breakdowns, a customer may also be responsible for it. They may lack awareness and information about how to prolong the life of and maintain their inverter. Topographical factors may add to this, for instance, lack of or irregular water supply or let’s say, non-availability of spare parts in remote areas, which may even be inaccessible in the first place for the manpower to travel to.

Sreenivasa M- Manager Sales at Sungrow adds to this view, “We at Sungrow have provided detailed guidance such as material handling, installation procedures and maintenance of the inverters in the our user manual. However we see few customers missing to follow on certain critical procedures or aspects such as providing sufficient ventilation, cleaning of air filters/fans, etc.”

Typically, a warranty on a solar inverter is between five to fifteen years. In India, extended warranties for 10 years and beyond are finally beginning to make an appearance as the market matures.

K N Sreevatsa, Managing Director, Fimer India, which has a strong portfolio of central and string inverters now says that the inverter offerings from the brand stand out from the O&M point of view, “FIMER inverters do not require any “additional” maintenance and are built to last for 25 years. Replacement of key components like power modules, contactors, breakers, filter are designed to last for 25 years. Inverter failure rate is less compared to other suppliers in the market.“ He goes on to add, “After-sales support plays the most crucial role. FIMER maintains critical spares and stock at regional levels and at major plant locations to avoid generation losses.  Our TAT(Turn around time)  is <72 hours.“

Idris Khan lends his voice to the age-old debate between central versus string inverters. “String inverter has more MPPTs, which has the advantage in high power generation for mountain and hilly ground power stations; secondly, the power loss caused by environmental changes (such as rainfall, cloudy, wind and sand) is smaller. Low power consumption and high system efficiency. String inverter system does not need to be equipped with inverter room, which can reduce the efficiency loss caused by lighting or cooling system.” From the O&M point of view too, he claims that string inverters are a clear winner over central inverters, “The power station designed by series inverter is a modular design, which can simplify the future operation and maintenance.  When a fault occurs, it is easy to replace, the power station cannot stop, resulting in a small loss of power generation, while the breakdown of central inverter will cause the overall shut down of power station, resulting in more financial losses. Compared with the centralized power station, the DC current of the string power station is smaller, and the connection point is relatively independent, so it is relatively safe.”

Shilpa Urhekar, National Head For EPC Solar Business at Sterling and Wilson Renewable Energy, one of the largest solar EPCs worldwide, on the other hand, does not see any reason to move away from Central Inverters yet. “String inverters have come up as their pricing became more competitive, their power output handling improved. They promise lower downtime, higher uptime… However, I still see central inverters as part of the mainstream. For large utility scale projects, they will stay relevant”.

Khan accepts that for large projects on level land, “The centralized inverter has the advantages of integration with lower cost per watt, high power quality, and it is relatively better for power grid regulation.”

Urhekar avers that even Huawei, which handed over its India inverter business to Wattpower, has met all it’s SLA (Service level agreements) post handover, giving customers like her vindication for trusting the brand.

Sreenivasa M of Sungrow adds that “With the help of Sungrow R&D team, we have been  able to introduce highest rating string as well as modular design central inverters. Both have various benefits such as savings on the BOS and easier O&M activities involved, which it makes viable to use for large utility projects. Nowadays, new central model also comes with modular design and technology like SUNGROW 1+X series, which increasing the uptime and availability of plant ultimately ensuring optimum generation from plant.”

Aniket Sawant, Regional Sales Head – West & Central India, GoodWe places his bets on string inverters over central inverters, “If we talk about market share of utility scale projects , we understand that 3-4 years ago, the Indian market had complete inclination for central inverters.

However, over that past 3-4 years, the scenario has changed a lot and major developers in India have started giving preference to string inverter over central inverter. The main reason for this is long term benefits like higher generation, O&M ease and BOS optimization vis-à-vis central inverter. Major string inverter manufacturers including Goodwe have gained significant stake in utility scale projects across India with major developers. And we believe in upcoming days this stake is going to increase rapidly compared to central inverters.”

Residential vs C&I

With practically every industry insider betting on a resurgence in these two segments, it’s a buyers market for customers. With a range from 1kW to 250 kW for this segment, the majors have their pitches ready. Eric Zhang, Global Sales Director at Solis India, says

“Designed specifically for commercial rooftop applications, the 110kW utilizes best-in-class components to deliver an industry leading efficiency and performance. Working together with our commercial customers we can ensure that the maximum energy yield and ROI is realised.”

Sandeep Goyal says, “Picking the right inverter is important in all categories Pyramid Inverters are 1.5% to 2% more efficient than all the inverters available in the market. 100% made in India with SiC technology.” For the uninitiated, Sic technology refers to silicon carbide  inverter. It promises higher efficiency at  smaller size.

Sreenivasa M., however, concludes with some words of wisdom to enable a customer to make choices when buying a solar inverter,“Choosing the right inverter rating as per the guidelines of the local discom or nodal agencies is very important. However, the inverter rating should also be considered in such a way that it meets the project capacity and also the commercial aspects to benefit both the EPC as well the end user.”

Emerging & Upcoming Trends

Storage & Hybrid inverters

One clear emerging segment is storage, and special inverters customised to serve this segment. Be it off-grid or on-grid, hybrid  and storage inverters have been launched by almost every player in the market today. Idris from Eric Zhang, Solis India Global Sales Director, which has a strong residential energy storage line, says with reference to this particular segment, “Residential energy storage are forecast to increase more than double in 2023 compared with 2022. The application of residential energy storage  projects are mainly in countries with relatively high electricity prices, such as Europe, North America and Australia. Therefore, residential energy storage market is expected to have continuous growth this year.”

Sungrow, which claims to be among the leading BESS solution providers across the globe is currently supporting many tenders that are being floated in India and also expecting a higher  market portfolio in small C&I from captive user and as well as giga watt hour scale tenders from well known developers with the firm’s products to cater both C&I & large scale utility projects.

While Sreenivasa places his bests on C&I and large scale utility, Sandeep Goyal is bullish on hybrid inverters and concludes that “hybrid inverters will take lead at least in the Indian Market due to power cuts.”

KN Sreevatsa, Managing Director, Fimer India says that Hybrid & storage inverters will play a big role in coming future. ”With the advent of Sodium ion batteries in market now, battery cost reduction will take place due to which BESS/Storage projects will be more viable. Govt is also pushing storage projects as increase in consumption  has led to burden on existing grid. Storage projects will support and stabilise the grid. Functions like load levelling, grid stability , frequency control etc are supported by our FIMER PVS980-58BC bidirectional converters , which are key requirements to maintain existing grid.“

Innovation

Like Formula 1, where auto makers invest to demonstrate and discover innovations that can be transferred to their mainstream products eventually, innovations in the inverter space matter a lot to demonstrate tech leadership. Capabilities like IoT were unimaginable a decade back, but common today.

Khan tells us, “The next biggest innovation of the inverter will be the application of the third generation semiconductor technology. The third generation materials represented by SiC and GaN can further meet the development needs of inverter with high efficiency, high frequency, small volume and high power. Take SiC semiconductor as an example: for an inverter with the same power, the weight and size can be reduced by 30% to 40% by using SiC power semiconductor design, and the inverter temperature can be reduced by at least 10 ℃.”

Sandeep Goyal says that Pyramid has already begun manufacturing inverters with latest technology available based on SiC.

He adds, “AI technology is gradually being integrated into the photovoltaic inverter, including the intelligent Imurv curve technology which is being successfully applied on a large scale.

“The second is the photovoltaic energy storage management function. The application of optical storage system further drives the evolution of the inverter to the power plant energy management center. Then there is the security management function. The inverter with functions such as DC arc detection, rapid shutdown of components and protection evolves the safety protection of photovoltaic power station from passive to active, forming active early warning and protection. Finally, the intelligent network, the formation of multiple complementary control, the source-grid-load-storage integration of the smart structure.”

From the Customers’ lens: Maintenance factors for solar inverters Warranty: Ask the right questions. Can the warranty be transferred for instance to someone who buys your home? Does the warranty cover maintenance services availed from outside the original brand that you purchased it from? Does the warranty still remain valid if you shift locations? Does it extend to DIY maintenance? Does it cover faults and breakdowns created by extreme weather? Insurance: It would be a good idea to avail insurance for your solar inverters. Yes, they can be insured since solar panels are covered under insurance. That way, you do not have to worry about the damage and can claim it when mother nature unleashes her wrath through floods or hurricanes or earthquakes. Or any other damage. Over the past several years, insurance companies have emerged as major investors in solar energy assets. Active solar insurers include Royal Sundaram, Tata AIG, ICICI Lombard and others. Bonus tip: ensure that your solar inverter comes with a handy manual to help troubleshoot problems. In off grid situations, one of the primary reasons that leads to the breakdown of an inverter is of course overloading. So, go easy on other electronic appliances and their consumption, which will also relieve your pocket of electricity bills. One way to avoid overloading is by investing in an inverter whose power output rating is equivalent to the continuous power and surge power rating of the appliances in use.