Infini Co Ltd will complete a solar power plant with an output of about 2MW and a 1,500V DC (direct-current) circuit in the spring of 2018.

Infini (Naniwa-ku, Osaka City), which deals with solar power generation-related businesses, is responsible for EPC (engineering, procurement and construction) and O&M (operation and maintenance) services for the plant and is currently constructing it.

Infini manufactures and sells solar panels under the brand of "Japan Solar" and deals with EPC services for mega (large-scale) solar power plants. It has already provided EPC services for about 100MW of solar plants. The company has been dealt with mainly DC1,000V designs, and this is the first time that it has designed a solar power plant with a 1,500V DC circuit in the aim of improving system efficiency with the high voltage.

A mega solar plant that Infini built in Hodatsushimizu-cho, Ishikawa Prefecture (source: Nikkei BP)

The 1,500V-compatible solar panel that Infini manufactures in Japan (source: Infini)

TMEIC's "Solarware2500" PV inverter with a rated output of 2.5MW supports a DC input of 1,500V. (source: TMEIC)

For the plant, Infini will set up 1,500V-compatible solar panels that it manufactures in Japan (270W polycrystalline silicon solar panel consisting of 60 cells). Also, it employed Toshiba Mitsubishi-Electric Industrial Systems Corp's (TMEIC) "Solarware2500" PV inverter (rated output: 2.5MW). This is the first 1,500V-compatible product manufactured by a Japan-based maker. It can be installed outdoors without housing.

1,500V mega solar plants are becoming the mainstream outside Japan (e.g. in the US) because they have many advantages such as high system efficiency, short construction period and low-cost O&M.

In Japan, Looop Inc (Bunkyo-ku, Tokyo) used General Electric (GE) Co's PV inverters to build its power plant with a 1,500V DC circuit in Ibaraki Prefecture. However, because the main components of 1,500V mega solar plants are manufactured outside Japan, some express concern about, for example, O&M services after the start of operation.