Since our last string inverters buyer’s guide was published in 2012, a few manufacturers have exited the market (Exeltech and Opti-Solar)—but some new ones have stepped in (Chint Power Systems, Danfoss, Eaton, and Eltek). This year’s guide profiles each inverter manufacturer and summarizes its residential products.
The table includes single-phase, UL-listed batteryless inverters with AC output power ranging from 1.5 to 11.0 kW. They are all Go Solar California-eligible inverters (per SB1 guidelines), and are distributed in the United States.
Chint Power Systems (chintpower.com/na) is headquartered in Shanghai, China, and was established in 2009. The company specializes in utility-interactive PV inverters for all market segments. Products and services include power transmission and distribution equipment; low-voltage electrical products; meters; engineering, procurement, and construction; PV modules (as Astronergy); and automotive parts. Chint Power Systems’ U.S. subsidiary is based in Dallas, Texas.
Chint’s original line of residential inverters (CPS-SCE) are available in 4, 5, 6, and 7 kW models. Its second-generation inverter (CPS-SCA; consisting of 3, 4, 5, and 6 kW models) includes arc-fault protection and dual MPPT inputs. Both inverter lines are transformerless and have a CEC-rated efficiency of 96.5% to 97%.
Danfoss (danfoss.us/solar) was founded in 1933 in Nordborg, Denmark, where its headquarters remain. Danfoss offers solar inverters as part of its larger focus on energy efficiency, but also offers products in refrigeration and heating. Its U.S. inverter facility is located in Loves Park, Illinois.
While Danfoss manufactures large industrial central inverters (1 and 1.5 MW) at its Illinois facility, its residential DLX string (2, 2.9, 3.8, and 4.4 kW) inverters are manufactured in partnership with Eltek and have CEC efficiencies ranging from 96.5% to 97%.
Delta (delta-americas.com) was founded in 1971 and has headquarters in Taipei, Taiwan, and in Fremont, California, with sales and manufacturing plants throughout the world. Delta manufactures power supply products for computer, telecommunication, medical, and industrial industries, as well as products for PV applications.
Delta offers the Solivia TR string inverters in the United States. This line includes four units with rated power specifications ranging from 2.5 to 5 kW, and CEC-rated efficiencies ranging from 95% to 95.5%. Delta also manufactures five transformerless (TL) models (3 to 7.6 kW), which include arc-fault protection and have a CEC-rated efficiency of 97.5%. The 5.2, 6.6, and 7.6 kW TL models have dual MPPTs. All Delta inverters have NEMA 4 enclosures.
Eaton Corp. (eaton.com) was established in 1911. Eaton is a global power management company with headquarters in Dublin, Ireland, and U.S. headquarters in Cleveland, Ohio. Eaton’s electrical sector business group includes power distribution and power quality products and services. Besides manufacturing inverters, Eaton supplies DC combiner boxes, DC and AC disconnects, and electric vehicle chargers.
Eaton’s residential inverter line consists of four transformerless models ranging from 4 to 7 kW, with a CEC efficiency of 97%. These inverters have a wide MPPT input voltage window—from 105 to 500 VDC.