String Inverters Increasingly Being Used in Megawatt-Scale PV Projects

In a sign of their growing acceptance, string inverters are increasingly being considered in megawatt-scale photovoltaic (PV) systems, with over 40 percent of inverter buyers regarding them as suitable for use in systems larger than 1 MW, according to a new report from IHS Technology.

SolarEdge string inverters

SolarEdge string inverters

In an IHS survey, more than 300 solar installers, distributors and engineering, procurement and construction (EPC) companies were asked about their preferences and opinions on PV inverters, in order to help suppliers better understand the needs and requirements of their customers.

Of the more than 200 purchasers of PV string inverters that completed the survey, 80 percent indicated they might use string inverters in systems larger than 100 kW. All told, nearly half reported they would consider using the inverters in systems larger than 1 MW, as shown in the attached figure. This marks a huge increase from the previous year’s survey when only 17 percent considered using string inverters in systems larger than 1 MW.

“The survey confirmed that the acceptance of string inverters in large systems has accelerated over the last year, mirroring the IHS forecast that these products will gain share in several key PV markets,” said Cormac Gilligan, senior PV market analyst at IHS. “The most common reasons given for solar purchasers preferring string inverters increasingly over central inverters in large systems were better system design flexibility, minimizing losses in the case of failure and lower lifetime system costs.”

IHS predicts that low power three-phase inverter shipments will increase by 14 percent a year on average for the next four years, with annual shipments of nearly 20 GW in 2017.

PV inverters convert the direct current (DC) electricity produced by solar panels into alternating current (AC). In the past, the use of string inverters has been limited to small-scale PV installations.

These findings can be found in the report, “IHS PV Inverter Customer Insight Survey,” from the Power & Energy service of IHS.

Chinese inverters continue to gain acceptance

The report also found that Chinese-made inverters are gaining increased acceptance in places such as the United States, Germany and the United Kingdom.

Chinese inverter suppliers appear to be overcoming the perception that their products are not of adequate quality. When buyers were asked the question, “Do you think Chinese inverters offer sufficient levels of quality?” half answered yes. This shows that the global level of acceptance for Chinese inverter suppliers has increased for a second consecutive year, Gilligan remarked.

The biggest increase was recorded in United Kingdom, where nearly 60 percent of inverter buyers consider Chinese inverters to be acceptable quality, compared to 40 percent in the U.S.

“The last two years have seen the United Kingdom transform quickly from a booming new market with a highly attractive feed-in tariff (FiT), to a steady-growth, low-cost region with lean subsidies,” Gilligan noted. “As a result of high price pressure in the U.K., the country has become a strong focus for Chinese suppliers, which have been able to gain a foothold in Britain. The price declines in the U.K. have been driven by regular reductions to the FiT and the many systems being designed to meet minimum renewables requirements in new buildings at the lowest possible upfront cost.”

Microinverters continue to advance

More entities are also using or buying microinverters in 2013, according to the survey, with 42 percent now utilizing such products.

Microinverters perform the same general functions as traditional string inverters except that they work on a per-module basis rather than for a string of modules.

The United States continued to show the highest levels of microinverter usage with a small increase over the previous year, while larger gains came from the European markets. In the United Kingdom, for instance, over half of purchasers now use or buy microinverters.

“Following several years of intense marketing and training for installers, microinverters have now progressed from being a ‘niche’ product, to gaining wide acceptance in the PV market,” said Gilligan. “Major suppliers, such as SMA and Power-One, have also released microinverters—helping them to gain acceptance and traction in key markets.”

— Solar Builder magazine





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