Review: M-KOPA Solar Home System

As I came off a hot and dusty Nairobi street into the bustling Safaricom shop, people were lining up for brand-new Android smartphones. But I was far more interested in a small stand showcasing a solar lighting and phone charging system from mobile start-up M-KOPA.

These systems come in two flavors: One consists of a control box, solar panel, USB phone-charging cable, and three LED lights, and the other adds a portable lamp, and a solar chargeable radio to the mix. The control box itself is a lightweight, hardcover book-sized gadget that has a strong rechargeable battery, a GPS cell modem, LCD status screen, and connection points for a 4-watt solar cell, LED lights, and a USB port. The units are designed and manufactured by U.S. solar lighting startup d.light Solar. Each M-KOPA Solar device is set with a unique customer ID number that is used to add credit to the user's account.

Currently available only in Kenya – a country where the innovative payment plan arguably has the biggest impact – the cheaper version of these two solar systems retails for 2,500 KES, or Kenyan shillings (that's roughly $29). But that initial price is actually a deposit, which you must pay to take the device home. After that, you need to pay 40 shillings per day (about 45 cents), to keep the the device operational. To give you perspective on what that means for Kenyans, according to CIO East Africa, "an estimated 3 million Kenyan homes or 80 percent of the population living off the power grid spend an average of 70 KES daily on kerosene and phone charging."

The beauty of the M-KOPA pricing model is that for consumers it resembles the prepaid electricity model that is becoming the norm in Kenya and other African countries. But in reality your daily payments are part of your "rent to own" agreement with M-KOPA, so after you buy 360 days' worth of electricity, you own your system outright, and no longer have to make daily payments.

All payments are done through Kenya's ubiquitous M-PESA mobile payment system, so that customers can make them directly from their mobile phones. M-KOPA's built-in modem checks your payment status on a regular basis, and the number of days of credit remaining is clearly shown on the control box's display.

After some initial hassle getting the unit fully paid off and unlocked, I brought the system home to South Africa for some serious outdoor stress testing. My unit sustained several days sitting outside in brutal Cape Town winter storms. Even the "do not expose to outdoor weather" control box survived, despite being immersed in rain, cold temperatures, and direct sunlight.

In my test run of charging an iPhone 4S from scratch, it was able to recharge the phone fully within 3 hours, using up about half of the M-KOPA's built-in battery. The provided USB cable offers an octopus of connectors for charging almost any mobile phone: Micro USB, Mini USB, Nokia 3.5mm and 2mm, and Samsung's feature-phone charging connector. And if that's not enough for you, any USB charging cable can work in the standard USB port.

The three provided lights are made of a bright and cheery red plastic, each with a long (about 10 feet), heavily insulated cable ending in a standard 3.5mm phone connector – the standard headphone jack used in most audio equipment. While an unusual choice to use as a power connector, it seems to do the job nicely, with the added advantage of being easy to extend, repair, or replace using commodity parts.

Each light also has a 3.5mm headphone jack on it, allowing all three of them to be daisy-chained together if need be. The light itself is provided via a single white LED, which can be dimmed to any one of four settings, ranging from "reading light" to a surprisingly bright room light.

My unit did have a few minor bugs: The LED indicators showing each port's connection status never lit up, and the LCD's battery strength indicator showed "full" when the unit was not completely charged. But these were minor imperfections in an otherwise amazing and versatile gadget.

Families in Africa looking to set up a simple and low-cost home lighting and phone charging system won't find a more innovative, portable, and rugged system than the M-KOPA.

And this is a product that would be likely be a big hit in the U.S. – primarily for the utility of an easy-to-use, well-built solar charger, whether you're camping off the grid, or you're in need of some extra light in your garage. The payment model doesn't make as much sense in the States, though it does make sense elsewhere in the developing world. The M-KOPA is addressing a very particular need, and it's one that's not unique to just Kenya.

Photos: Elizabeth Gould/WIRED