au Energy & Life introduced 'au Denchi' on May 13, 2026, offering home storage batteries with zero upfront, installation, or monthly fees. Available in Tokyo, the service provides up to 3,000 JPY monthly discount on electricity bills by utilizing batteries for grid stabilization. Partnering with Sumitomo Electric and Eneres, the system also functions as an emergency power source during outages while supporting CO2-free energy through the 'au Denki eco plan'.