Takenaka Sets Up System to Supply DC Solar Electricity to Lighting Equipment

2019/07/18 21:43
Sousuke Kudou, technical writer
The Kurihara Kogyo Building (source: Takenaka)

Takenaka Corp announced July 3, 2019, that it has introduced a direct-current (DC) power supply system for office lighting equipment in a commercial building.

It uses the "I.SEM" energy management system developed by Takenaka. And it was introduced in "Kurihara Kogyo Building," an office building of Kurihara Kogyo Co Ltd (Osaka City).

According to Takenaka, it is Japan's first such system that supports BCP (business continuity plan) and combines demand response (DR) and DC power supply.

The DC power supply system that Takenaka introduced this time is "I.SEM+DCPS (direct current powered system)." It takes in DC electricity from dispersed power sources such as solar panels (total output: 10kW), storage battery (capacity: 72kWh) and electric vehicles (EVs) without conversion to minimize the costs of energy and energy management. It enables the use of renewable energy and the rational use of energy for BCP.

In general, a power distribution network in a building uses alternating-current (AC) electricity. So, it causes a loss at the time of DC-AC-DC conversion for operating electric devices.

The introduction of the new system reduces conversion loss by about 10% (at the time of operation at a rated output) by supplying DC power to the lighting equipment in the third floor of the building, which is used as a shelter at the time of disaster.

Takenaka asked Panasonic Corp to newly develop the lighting equipment. The names of the manufacturers of the solar panel and storage battery employed for the building were not disclosed.

The Kurihara Kogyo Building has a steel structure and eight floors above ground and one below. It was designed and constructed by Takenaka.

The plan to realize both (1) the business continuity of the DC power supply system, etc and (2) the reduction of CO2 was highly evaluated, and the building was selected for the general category of the "1st Project for Leading Sustainable Buildings, Etc in Fiscal 2017 (type leading the reduction of CO2)" of Japan's Ministry of Land, Infrastructure and Tourism. The building was completed in March 2019.