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Sion Electric to Install Its Power Supply System in More Locations for Verification

'Ecominohru' supplies DC solar electricity for in-house consumption

2016/10/28 13:47
Kenji Kaneko, Nikkei BP CleanTech Institute
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The "Ecominohru" being introduced for verification (source: Nikkei BP)

Sion Electric Ltd will increase the number of organizations, etc that use the "Ecominohru" power supply system designed for consuming solar electricity in house for verification.

Sion Electric (Higashi-ku, Hokkaido) is a company that researches and develops power systems for offices. In addition to five locations in which the system has been introduced for verification such as Tohoku University, the company will install it in more locations to collect more data for verification in the aims of further improving the system and commercializing it.

The Ecominohru consists of (1) a 2kW DC-DC converter that supplies DC (direct-current) solar electricity to electric facilities without DC-AC conversion and (2) a 3kW AC-DC converter used to supply commercial electricity (from a power grid) when the amount of solar electricity is not enough. Sion Electric expects that the Ecominohru will be used to supply electricity to LED lighting equipment and air-conditioning systems whose power supply units are modified to support direct-current input.

Compared with conventional in-house consumption systems that are connected to an AC (alternating-current) on-site (private) grid via existing PV inverters, the Ecominohru can reduce loss of solar electricity by 6-7%, Sion Electric said. Also, unlike commonly-used PV inverters, the Ecominohru uses Sion Electric's own pattern control method instead of MPPT (maximum power point tracking) control, and it features a simple circuit design and can potentially realize a low cost.

By preferentially supplying solar electricity to air-conditioning systems and lighting equipment, which account for about 70% of the power demand of office buildings, it becomes possible to drastically reduce the amount of commercial electricity purchased from a power grid.

In a joint research with the Graduate School of Environmental Studies, Tohoku University, 66% (yearly average) of the power demand of a 2kW air-conditioning system and 0.5kW LED lighting equipment (hours of operation: 8:00-17:00) was met by 2.5kW of solar panels, according to Sion Electric.

The company expects that companies considering installing solar panels, small hydroelectric generation systems, fuel-cell systems, etc will introduce the Ecominohru for verification.