North of Nairobi, for example, the lush, farm-laced hills gradually give way to the semiarid landscape of the Laikipia District, 2 million acres framed to the east by Mount Kenya, to the south by the Aberdare Mountains, and to the west by the fossil-rich Great Rift Valley.
In contrast to the depletion economics that drive up the cost of fossil fuels over the long run, solar power is a Silicon Valley-style energy resource: the more we make, the more we learn, innovate and lower the cost of the technology.