Botswana must have more solar water heaters per head than just about any country. I don't have statistics, but the rooftop panels are ubiquitous. Botswana is a relatively poor country, but I was surprised to learn from the UNDP country factsheet that the country in 2005 had a higher GDP per capita than neighbouring South Africa, which is the economic powerhouse of sub-Saharan Africa. Botswana produces 2.4 tonnes of CO2 per person annually, which is higher than the sub-Saharan average of 1.0, but I suspect that the widespread use of solar power is not the result of policies to reduce emissions. It is more likely because many people do not have access to electricity from the national grid, and because solar water heating makes economic sense.
For the same reason, there are a number of widespread applications for photovoltaic panels, though not all of them are mainstream. I have been to Botswana a number of times, but this week was the first time I saw pv panels being used by the informal businesses that supply a privatised form of public phone - people using cell phone connections to offer a service to the public, as in the picture above.
After I saw this one in Gaborone, I kept an eye out for other pv applications. I did not see a single one on the roof of a building, but I did see one powering a true public phone on the road between Gaborone and Francistown, just south of Serowe. And on the same road, just north of Gaborone, was this cellular tower with pv panels.
What I found interesting about this one, was that when I took the picture - at the end of a hot, sunny day - a diesel generator was running at the base of the tower. Which highlights one of the key problems with high-tech solutions: if there isn't the budget and the inclination and the skills to maintain the infrastructure, the capital investment is a waste of money.