The archive · Climate & Energy · Financial decision · 2007–2026
Sun King's PAYGo bet: $0.15/day lanterns to a $286M securitized solar portfolio
Sun King bet off-grid households would buy solar in tiny installments; 82M people reached, $260M Series D, then a landmark $286M securitization in 2025.
Sun King
What the business is
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.
Starting capital：$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.
How it started
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.
What happened
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.
How it ended up
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.
Background
Sun King began in 2007 as Greenlight Planet, born from a University of Illinois dorm-room observation by T. Patrick Walsh that rural villagers needed healthy, affordable lighting; Mayank Sekhsaria and Anish Thakkar joined to design solar lanterns. The founding bet was that the 1.8 billion people without reliable electricity would buy solar if they could pay in small daily installments — as little as fifteen cents a day through the 'Easy Buy' pay-as-you-go option — instead of a grid connection they could never afford.
The model scaled. By June 2016 Greenlight Planet had sold 5M+ products in 54 countries and reached 20M+ people, winning the Ashden International Award. After rebranding to Sun King, the company deepened its PAYGo business across Kenya, Zambia, Uganda, Tanzania and Nigeria, and in April 2022 closed a $260M Series D led by General Atlantic's climate arm BeyondNetZero — saying it had delivered solar to over 82 million people and sold in more than 40 countries over its 15 years.
The payoff came when Sun King proved its receivables were bankable: in mid-2025 it raised $286M by securitizing pay-as-you-go customer payments, bundling future installments as collateral for debt sold to institutional investors — a landmark for off-grid solar, alongside d.light's $50M green bond. GOGLA's executive director called the deals proof that the model works, while Sun King's CFO warned the main risk is portfolio quality and that chasing capital-market returns could pull the industry toward larger, easier customers and away from the poorest households.
What has to be true
- 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.
What can be applied
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.
Aftermath
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.
Sources
- Greenlight Planet wins award for delivering affordable solar energy products
- Solar provider Sun King raises $260 million
- Africa's off-grid solar sector courts investors with landmark deals
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