Juba's power supply is, to put it mildly, poor. In its defense, however, the town has been in a shambles for the past 50 years due to neglect from the central government in Khartoum. This administration were simply handed over a shell of a city and expected to make it function. A monumental task for any civilization.
But back to the power situation. Many businesses rely on self generating power supply, mainly in the form of standby diesel generators. Most find that in a very short time, their assumptions about consumption (fuel and service) far exceeds what they planned. Diesel is expensive; it comes by truck from Khartoum and Kampala. Spares are equally expensive -- and often hard to find when you need them most. If businesses plan to use standby diesel power, carefully calculate the costs involved -- and then add 40%.
An alternative, until the power grid is improved, is solar. My office and house are all powered by solar alone. 24-7 power, clean and really service free. Start up costs are about 2-3 times that of a diesel genset, but the break even point (the point at which the cumulative fuel and service costs equal that of the solar set up costs) is about 5-6 months (depending on the size and quality of the genset). Worry free, environmentally sound and cost savings. It's even better for businesses in remote locations where diesel, spares and service are even more expensive.
Start up costs are about $7-10000 for the first KVA, about $1000 for every KVA thereafter. Check with your local solar expert for more details.