NTT DOCOMO is launching field tests of three conventional mobile-network base stations that have been installed with solar panels, high capacity rechargeable batteries and green power controllers.
NTT DOCOMO will install 10 green base stations in the Kanto-Koshinetsu region of Japan by late summer, including the first three in Tokyo, Kanagawa and Yamanashi prefectures. The equipment was already by tested at its R&D Center from March 2012 to February 2013.
The green base stations use solar panels to generate and store solar power during the daytime. If commercial power supply is cut off during a disaster, the station can rely solely on this power to run communication equipment during the day and use high-capacity, rechargeable batteries to store 14-16 hours’ worth of power when solar power is not available.
The solar panels to be used in the field test generate up to 4.19 kW, whereas the maximum power consumption of a base station is 2.0 kW. Remotely controlled green power controllers will manage power used by the base stations, including utility-provided electricity, solar panel-generated electricity, and high-capacity, rechargeable batteries that discharge their energy as required.
The company said its interest in disaster-proof, environmentally friendly base stations was spurred by the Great East Japan Earthquake. NTT DOCOMO is also considering fuel cell technologies and wind-powered base stations.