Remember the satellite photo of earth at night?
A few weeks ago I visited a solar power plant in rural Mali, West Africa. The plant became operational within the last year, replacing mainly gasoline generated power.
The plant is in a small town called Ouelessebougou, which, together with surrounding towns has about 12000 residents, most of whom live off of a few dollar a day.
The plant is actually a hybrid of solar power and gasoline power. At night, or during a cloudy day, after the battery farm has been depleted, power is switched to gas generators. Mali has no significant petroleum reserves, and gasoline is about $5USD per gallon, so presumably the investment in the solar field will be economical (not to mention environmental benefits). 
One knows when energy is being switched between solar and gas because power is cut to the entire village for a few seconds while the operator turns a giant switch (picture of switch missing).
The distribution of solar and gas power is about 50/50. On the day that I visited, the town consumed about 6000 KWH of energy, with about 3000 coming from solar and about 3000 coming petroleum (to the best I could estimate from the hand written log books that I looked at). 
Assuming that 10% of households in and around Ouelessebougou have access to electricity, this puts their consumption is about 5KWH per day.
By contrast, the average american consumes 238 KWH per day. This doesn’t represent the total amount of energy consumed, as 90% of energy in Mali comes from wood fuel. But speaking only of electricity, one can see why the continent is dark. 
While Africa benefits from higher intensity sunlight than America or Europe, higher temperatures effect the efficiency of solar panels, and I was told that energy prices have gone up significantly with the inauguration of the power plant, to pay for its construction.
I read on an NGO website that solar power in sub-saharan Africa would help cut down CO2 emissions as people began cooking with electricity instead of wood and coal. But of course the people I encountered were more concerned with having access to TV and computers than more environmentally friendly cooking, a choice I don’t think any of us could criticize.
