Off-grid solar company Sun King’s Zambia subsidiary has received a $5 million equity investment from Acumen’s Hardest-to-Reach (H2R) Catalyze initiative to support the company’s expansion in the country and help it access local currency financing.

Sun King designs, finances, distributes, installs, and services solar systems for households and businesses with limited or no access to electricity.

With Acumen’s support, the company is expected to provide electricity access to nearly 5.6 million people in Zambia over the next five years. According to Acumen, up to 4.5 million of these people are expected to gain electricity access for the first time.

In 2025, Sun King raised $40 million in equity financing from Lightrock, a global sustainable investment platform, to support its expansion of decentralized solar energy systems across Africa and Asia and to advance the development of new products for underserved households and businesses in these regions.

The company, formerly known as Greenlight Planet, raised $260 million in a Series D funding round in May 2022 led by BeyondNetZero, the climate investing venture of General Atlantic, along with other investors.

Founded in 2007, Sun King operates across Africa and Asia and provides off-grid solar products and financing to customers without reliable access to electricity. It offers solar products ranging from entry-level solar kits for lighting and phone charging to multi-kilowatt solar inverter systems designed to power large homes, businesses, schools, and public health centers.

The company uses a pay-as-you-go financing model that allows customers to purchase solar systems through loans repaid over 12 to 24 months. Customers can make daily, weekly, or monthly payments through mobile money, starting at $0.26 per day.

Zambia is one of the target markets for Acumen’s H2R initiative. According to Acumen, only about half of the country’s population has access to electricity, with substantially lower access in rural areas. The investment will support Sun King’s expansion in Zambia, where Acumen has identified significant unmet demand for reliable and affordable electricity. Acumen said severe droughts in recent years have also reduced hydropower generation, which accounts for most of Zambia’s electricity supply.

In 1H 2026, VC funding activity in the solar sector decreased 40% YoY to $1.5 billion, down from $2.5 billion in the first half of 2025. Deal activity increased 9% YoY, with 35 deals in the first half of 2026 compared to 32 in 1H 2025, as per Mercom’s recently released 1H and Q2 2026 Solar Funding and M&A Report.