Location: Japan

Product composition:

Demuda 13.2kW inverter * 1PC

Demuda 15kWh battery 1 * PC

455W solar panel * 12PCS

This case is the off grid solar power generation system independently built by Mr. Peter, who lives in Japan. The design and material selection were completed through DIY, and only a Chinese construction team was commissioned to assist in the construction. The system is compatible with Japanese power supply standards and has excellent operational performance, providing a cost-effective practical reference for overseas users to independently build photovoltaic systems.

1、 Project Background

Due to the high local professional installation prices in Japan without subsidies, and the need for JET certified equipment for grid connection, Mr. Peter chose to build his own photovoltaic system to achieve self use and off grid power supply for households and reduce electricity costs.

2、 Core configuration and cost

The total cost of the system is 27000 RMB, and all equipment except for photovoltaic panels is purchased from China's photovoltaic energy storage company Demuda, perfectly adapted to Japan's single-phase three wire 100/200V power supply system:

Photovoltaic panels: total power of 5.46kW (12 pieces), purchased from Japan, with 6 pieces installed on the south/east roofs and the core power generation area on the south side;

Inverter: 13.2kW, adjustable to 100/200V, strong stability, suitable for multiple household appliances to start simultaneously;

Energy storage battery: 15kWh ensuring electricity supply at night and on rainy days;

Other: Auxiliary materials cost ￥2000, construction labor cost ￥5000 , and separate procurement costs for inverters/batteries/photovoltaic panels are ￥6000/8000/6000 each.

3、 Performance of operational power generation

The system will be put into operation on October 26, 2025, and has undergone tests in sunny, cloudy, and rainy weather. The first month's results exceeded expectations:

Power generation: Accumulated power generation of 474 kWh in the first month, with stable output even on cloudy days, meeting the electricity needs of households in all scenarios;

Power supply capacity: It can be completely powered off the grid on sunny days, and the electricity used during the day is borne by solar energy. At the same time, the battery is fully charged for night use, and only a small amount of mains electricity is needed for continuous rainy days;

Electricity Experience: Home hot water, cooking, various appliances, etc. can be used with confidence, and electricity bills have significantly decreased.

4、 Core highlights of the project

Strong equipment adaptability: Demuda inverters and batteries have successfully adapted to the Japanese power supply system, breaking down barriers to overseas equipment adaptation and offering outstanding cost-effectiveness;

Large cost advantage: The DIY construction mode significantly reduces installation costs, and has obvious advantages over professional installation in Japan;

Strong practicality: The system achieves true self use, eliminates the problem of rising electricity prices, and has strong autonomy in power supply;

Strong replicability: Clear equipment selection and installation ideas provide replicable landing solutions for overseas photovoltaic construction demanders.