Sun King's PAYGo bet: $0.15/day lanterns to a $286M securitized solar portfolio

The world's largest off-grid solar company: sells solar lanterns, home systems and appliances to households in Africa and Asia on pay-as-you-go terms.

That off-grid households would buy solar in tiny daily installments — make PAYGo the product's core and 1.8B people without grid power become a market, not aid.

$430M+ verified through April 2022: $170M in earlier equity and debt, then a $260M Series D (2022-04), led by BeyondNetZero with M&G Catalyst and Arch Emerging Markets Partners; plus $286M of securitized debt in mid-2025.

The idea took shape in a University of Illinois dorm room when T. Patrick Walsh saw that rural villagers needed affordable, healthy lighting; in 2007 Mayank Sekhsaria and Anish Thakkar joined him to build Greenlight Planet. The company sold solar lanterns under the Sun King brand and pioneered micro-financed purchases. By June 2016, when it won the Ashden International Award, it had sold 5M+ products across 54 countries, reaching 20M+ people, with payments as low as fifteen cents a day.

Sun King scaled the pay-as-you-go model across Kenya, Zambia, Uganda, Tanzania and Nigeria, then rebranded from Greenlight Planet to Sun King. In April 2022 it raised a $260M Series D — led by General Atlantic's climate arm BeyondNetZero, with M&G Investments' Catalyst and Arch Emerging Markets Partners — saying it had delivered solar to over 82 million people in 15 years. $100M of the round was earmarked to expand PAYGo and introduce larger systems able to power refrigerators.

Still scaling as the sector's largest player. In mid-2025 Sun King raised $286M by securitizing its pay-as-you-go customer receivables — bundling future installment payments as collateral for debt sold to investors, a first-of-its-kind scale for off-grid solar, alongside d.light's $50M green bond.

A billion-person market only becomes a business if the poor can pay; $0.15-a-day installments made solar purchaseable rather than charitable.

Sun King bet on commercial scale instead of donor subsidies, which is what made it attractive enough for General Atlantic's $260M Series D.

Years of repayment data became the company's real asset — it converted those records into a $286M securitization in 2025, the sector's first at that scale.

Hardware, financing and distribution sold as one bundle created the moat: copying the panel is easy, replicating a decade of clean repayment history is not.

Financing can be the product: tiny-installment payments turned a lantern into an owned asset, and a decade of repayment data into $286M of institutional debt — a moat smaller rivals can't copy.

As of September 2026 Sun King is still the largest off-grid solar company, selling home systems and appliances across Africa and Asia on PAYGo. Its mid-2025 $286M receivables securitization — called 'pathbreaking' by CFO Krishna Swaroop and proof the model works by GOGLA — marked institutional investors' entry into the sector, alongside d.light's June 2025 green bond. Swaroop cautions that portfolio-quality data remains the biggest obstacle for mainstream investors, and that chasing capital-market returns could push the industry toward larger customers and away from the poorest households.