Acumen’s Hardest-to-Reach (H2R) Catalyze initiative has invested $5 million in Sun King’s Zambian subsidiary to expand access to affordable solar energy across the country.

The equity investment is expected to support Sun King’s nationwide expansion while helping the company unlock additional local-currency financing from financial institutions. Over the next five years, the investment is projected to help Sun King provide electricity access to nearly 5.6 million people in Zambia, including up to 4.5 million people who could gain access to electricity for the first time.

Sun King develops, finances, distributes, installs and services solar energy systems for households and businesses with limited or no access to electricity. Its product portfolio ranges from entry-level solar kits for lighting and mobile-phone charging to larger solar inverter systems designed to meet the energy needs of homes, businesses, schools and public health centres.

The company operates through a Pay-As-You-Go (PayGo) model, allowing customers to acquire solar systems through loans repaid over 12 to 24 months. Payments can be made daily, weekly or monthly through mobile money services. Entry-level systems are available with payments starting from $0.26 per day, helping reduce the upfront cost of accessing electricity for underserved households.

Sun King Chief Financial Officer Krishna Swaroop said the company had identified strong unmet demand for reliable and affordable solar power among communities that remain outside the electricity grid.

He said the investment would provide the capital and confidence needed to accelerate Sun King’s nationwide rollout in Zambia and reach more households that lack reliable access to electricity.

The investment also represents Acumen’s first equity investment in one of Sun King’s country-level businesses. Acumen expects the equity support to help attract additional debt financing in local currency from domestic financial institutions, potentially increasing the overall scale of investment beyond the initial $5 million commitment.

Zambia remains an important energy-access market, with only around half of the population currently having access to electricity. Access is significantly lower in many rural communities, where extending conventional grid infrastructure can be challenging and costly.

The country’s electricity system has also come under increased pressure from severe droughts in recent years, which have reduced hydropower generation. Hydropower accounts for the majority of Zambia’s electricity supply, making the expansion of distributed renewable energy solutions increasingly important to improving energy resilience.

Sandra Halilovic, Head of H2R Catalyze, said Sun King’s experience in other markets, combined with growing demand for affordable clean energy in Zambia, supported Acumen’s decision to invest.

She said the investment would help accelerate Sun King’s expansion, contribute to closing Zambia’s energy-access gap and attract additional financing from local lenders.

Through the investment, Acumen and Sun King aim to expand the adoption of distributed solar energy and improve reliable electricity access for households and businesses across underserved communities in Zambia. The initiative also highlights the growing role of off-grid and distributed renewable energy solutions in addressing Africa’s electricity-access challenges.