In Rwanda, industry analysis estimates
that roughly 70% of the population have a cell phone, yet only 18% have access to electricity, according to the World Bank
Sketching the first design on a piece of paper, the entrepreneur devised a solar-powered kiosk that can be towed by bicycle and provides simultaneous charging for up to 80 phones.
His company, African Renewable Energy Distributor (ARED)
, operates under a micro-franchising system that leases the kiosks to agents.
Micro franchisees earn money from mobile charging and selling add-ons such as mobile credit, government certificates and prepaid electricity.
"It's a business in a box," said Nyakarundi, who moved back to Rwanda in 2012 once his prototype was ready. "I was looking to do something that would not only solve a problem but also had a social impact by creating micro businesses for people."
There are currently 25 kiosks operating in Rwanda, many in rural areas where the population is dependent on cell phones to communicate and send money.
But after four years of carefully testing his business model, Nyakarundi said he is now ready to seriously scale up. He plans to have between 600 and 800 kiosks in place by the next two years.
To run them, Nyakarundi says he looks for people who desperately lack employment opportunities.
The agents make just a $100 down payment followed by $200 in installments to lease their kiosk from ARED. From that, the company says existing vendors are making between 30,000 to 85,000 Rwandan francs ($38-$107) a month -- enough to pay rent and feed a family.
But strikingly, for micro franchisees who are women or have disabilities, the opportunity is absolutely free.
"They are the most vulnerable group in Africa, especially in business," said Nyakarundi. "Women don't have access to funding the way men do, and people with disabilities have even less opportunity."
Sembemba Jean Pierre suffers from a disability. He had to remove his child from school because he wasn't earning enough as a watch repairman. Thanks to the kiosk, his son is back in education and Pierre dreams of owning a house.
"I could go a whole day without getting someone to repair the watch for," Pierre told CNN by email through a translator. "Now I am at least assured of daily income -- my family don't sleep hungry anymore."
Prospective agents must be at least 25 years of age and have two letters of recommendation from leaders in their community -- paperwork that is enough to deter "the bad apples", according to Nyakarundi.