Major telecommunications carriers are making efforts to boost photovoltaic power generation through storage batteries solutions.

au Renewable Energy, KDDI, Tokyo Electric Power Holdings (TEPCO HD), and Eneris will jointly launch a storage battery business in the latter half of FY2025.

As the lead operator, au Renewable Energy will initiate the project by installing large storage batteries (1.5 MW output) at the KDDI Oyama Network Center in Oyama City, Tochigi Prefecture. In the first phase of the project, large storage batteries with a power output of 1.999 MW and a storage capacity of 5.608 MWh will be installed at the KDDI Oyama Network Center, led by au Renewable Energy.

Construction is scheduled to begin in December 2024, with operations expected to start in October 2025.

au Renewable Energy will oversee battery operations, while TEPCO HD will be responsible for designing the storage battery system and facility maintenance, leveraging its expertise in grid operations and lithium-ion batteries. Eneris will focus on electricity market transactions and battery charge control.

Meanwhile, Softbank and Enpower Japan have increased the energy density of their all-solid-state batteries to approximately 1.2 times the previous level, reaching 350Wh per kilogram. The battery has approached the capability of power sources for flying base stations (HAPS), which are used to communicate with the ground by flying unmanned aircraft. The aircraft are powered by solar panels on the fuselage, storing the generated electricity in the batteries, enabling continuous flight for about six months. The goal is to store around 400Wh of energy in the future.

The two companies aim to achieve 1,000 charge-discharge cycles for long-term HAPS usage by FY2026, with the goal of practical application around 2030. The two companies plan to begin long-term use of HAPS in FY2026. The two companies aim to achieve a durability of 1,000 charge-discharge cycles in FY2026 to withstand long-term use in HAPS, with commercialization around 2030. The two companies are aiming for practical application around 2030.