Green Growth Raises About ¥500M to Add Batteries to Solar Plants

Green Growth, a Japanese startup that helps owners of existing solar plants add battery storage, announced on October 29 that it has raised about 500 million yen (roughly $3 million at recent rates) in a seed round combining equity and bank debt.

The equity portion was led by ANRI through its ANRI Fund No. 6 partnership. Dogan, via its Dogan MGX fund, and Yusuke Toyota, president and CEO of Digital Grid, also participated. Loans came from Resona Bank and the Japan Finance Corporation. The company did not disclose how the money splits between equity and debt.

Why storage matters for solar owners

Many of Japan's solar plants were built by individuals and regional companies under the feed-in tariff (FIT) scheme. As capacity has grown, midday supply on sunny days often exceeds demand, and grid operators increasingly order plants to pause output, known as curtailment. Plants cannot sell power while curtailed. Over the 2030s, FIT periods will also expire in stages, and sale prices will fall to market levels.

According to the company, switching to the FIP scheme and adding a battery lets owners store midday output and discharge it in the evening and at night, when demand and market prices are higher. That limits curtailment losses, raises revenue and lets owners choose when to sell after their FIT term ends.

Services and next steps

Green Growth focuses on Kyushu, where curtailment became serious earliest. It acts as an outsourced renewable-energy division for plant owners, handling battery planning, coordination with contractors and utilities, commissioning and, after launch, aggregation: preparing and submitting generation plans and trading on power markets.

It says at least one client's co-located battery is already operating, with further projects due to start. The firm also develops grid-scale storage for investors and owners, and has certified environmental attributes from plants it manages and sold them to corporate power users. It holds retail electricity and specified wholesale supplier registrations, plus non-fossil value trading membership.

The new funds will go mainly to hiring and strengthening the organization, so the company can support more plant owners and build services that help corporate buyers design and execute power and environmental-value procurement strategies.