2013 String Inverters - Developments and Specifications

Integrators working in the North American market have a wide range of options and choices to make when it comes to string inverters. Our 2013 dataset contains extensive specifications for 111 single- and 3-phase models from 16 manufacturers.

The solar industry news wires have been buzzing in recent months with announcements of inverter manufacturer acquisitions and reports of fragmentation of the inverter supplier base due to shifts in sales capacities in core markets such as Europe, Asia and North America. For example, according to IMS Research, the total global market share for the 10 largest inverter manufacturers fell more than 4% in 2012.

While these developments—and their potential impacts on the solar industry—are fascinating to watch, many integrators are more interested in changes and advancements in the specific products they install. In this regard, the past year has been a great one for the industry. Several string inverter manufacturers have brought new products to market that offer higher power capacities and interconnection voltages, and features that increase design flexibility.

The core of this article presents comprehensive electrical, operational and mechanical specifications for 111 single- and 3-phase string inverters currently available in North America. Before you dig into the specs, the following information will help orient you to some of the high-level and model-specific changes that have occurred.

Notable Acquisitions and US Market Entries

Noteworthy developments in inverter manufacturing include Advanced Energy’s acquisition of REFUsol and ABB’s acquisition of Power-One. In addition, SolarMax, a Swiss inverter manufacturer, recently announced plans for a North American market entry.

While Advanced Energy’s announcement that it was acquiring REFUsol caught many industry pros by surprise, the pairing appears to be a great fit. REFUsol’s 3-phase 480 Vac inverters have been gaining traction in the US market and round out the commercial and utility-scale product portfolio of AE Solar Energy, Advanced Energy’s solar division. Advanced Energy noted that the acquisition would extend its geographical distribution into growth markets where REFUsol has a strong presence, including India, Asia and Eastern Europe.

At the time of publication, ABB’s acquisition of Power-One is still in process and the two companies are acting independently until the merger is complete. Therefore, related products are listed under Power-One in the following dataset. Once completed, the acquisition will establish ABB, a global power and automation technology group, as the second largest inverter manufacturer in terms of global market share.

Another recent development is an announcement by SolarMax, an established brand outside North America, of plans to expand into the US. SolarMax will be introducing a line of 1,000 Vdc string inverters with rated power capacities ranging from 12 kW to 18 kW. The products will have multiple MPPT inputs and NEMA 4X enclosures. A 75 kW 3-phase 480 Vac central inverter is also scheduled for launch in 2013.

US Market Exits

The 2012 version of our string inverter dataset included 121 products from 18 manufacturers, with six manufacturers entering the US market that year: Carlo Gavazzi, Chint Power Systems, Eaton, Eltek, Growatt New Energy and REFUsol. This represented a 33% increase in the number of string inverter manufacturers operating in North America compared to the previous year. In 2013, the number of manufacturers offering string inverter products in the US headed the other direction and fell by two, for a current total of 16. The number of available models dropped to 111.

Over the last year, three string inverter manufacturers either have discontinued production or no longer have a distribution presence in North America. Delta Energy Systems ceased the distribution of its Soliva string inverter line in North America, but continues to supply versions of these models to the European, Australian and Indian markets. Exeltech’s non-isolated XLGT string inverter is no longer in production. Additionally, there is currently no US distribution for Growatt New Energy inverters due to contractual issues between the joint venture partners. However, a resolution of these issues is reportedly under way.

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