When Patrick Walsh and Anish Thakkar began tinkering with solar lanterns in a university lab in 2007, they weren’t out to build a billion-dollar enterprise. They simply wanted to replace smoky kerosene lamps with clean, affordable light. Today, that humble mission has grown into Sun King, the world’s largest off-grid solar company — illuminating 25 million homes across Africa and Asia and raising more than $700 million in funding.
From a college idea to a global mission
The two met as students at the University of Illinois, where their paths unexpectedly crossed. Walsh, an engineering student working on rural biofuel microgrids in India, was searching for a better way to power remote communities. Thakkar, who led a cycling nonprofit supporting families affected by cancer, was drawn to projects that touched people’s lives directly.
Their shared curiosity sparked a small experiment — a solar lantern made from PVC tubes and LEDs. That prototype became the seed of a global clean-energy revolution.
Building Sun King
In 2007, Walsh and Thakkar officially launched Sun King. The first challenge was not technology, but access. Many families who needed solar light couldn’t afford it upfront. So, they introduced an innovative pay-as-you-go (PAYG) system, allowing customers to make small daily or weekly payments via mobile money until they owned their solar systems outright.
“Just having the right product wasn’t enough,” Thakkar recalls. “We needed to make it affordable and reachable for the people who needed it most.”
The first breakthrough
The turning point came when Thakkar pitched their fledgling idea to his former boss, Dr. Prabha Sinha, co-founder of ZS Associates. Sinha — who had grown up studying under kerosene lamps — became their first investor and mentor. With his backing, the pair set up operations in Mumbai and built a direct sales network of local agents known as Sun King Saathis.
From India, the company expanded westward into Africa, where energy poverty was most acute. Today, Sun King operates across 11 African countries, with over 300,000 new users added every month and 195 MW of installed solar capacity.
Financing the green revolution
Sun King has redefined how climate finance works in emerging markets. It has provided $1.3 billion in solar loans and pioneered the use of local-currency financing, raising over $450 million from African banks such as Stanbic and Absa.
“That’s huge,” Walsh says. “It’s not just donor money anymore — it’s African banks fueling Africa’s green transition.”
A landmark moment came with the company’s $156 million local-currency securitisation in Kenya, the largest of its kind in Sub-Saharan Africa outside South Africa.
Made in Africa, for Africa
In 2025, Sun King opened its first major manufacturing hub in Nairobi, Kenya, assembling solar-powered televisions and smartphones tailored for off-grid homes. The facility, with a capacity of 700,000 units annually, marks a step toward a fully localised supply chain. A similar plant is planned for Nigeria.
“Over 99 per cent of our 3,000 employees are African,” Walsh notes. “That’s not by accident — it’s the whole point.”
The company’s workforce now includes 35,000 field agents and 3,000 staff, creating over 38,000 green-energy jobs across the continent.
Friendship at the core
Behind the numbers lies a partnership built on trust and shared purpose. “We’ve been through good times and brutal ones,” says Walsh. “Anish is one of the most important people in my life.”
Their friendship remains the steady flame behind a company that continues to grow while staying true to its mission: bringing light to every home that needs it.
“We started in a lab soldering lanterns,” Thakkar reflects. “Now we’re powering millions of homes. But the goal hasn’t changed — to light up the world, one home at a time.”
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