Sustainable Mountain Development - Mountain Geography: Physical and Human Dimensions - page 627

FIGURE 12.15 The reservoir of Lake Oberaar in the Swiss Alps. Here, as in mountain regions gener-
ally, hydropower is generated mainly to serve the needs of downstream areas. Mountain regions
ought to be compensated adequately for such services. (Photo by M. F. Price.)
POWER FROM WATER
The steep gradients of mountain rivers and streams mean that they have great potential
for generating energy. The simplest technology is the water mill, developed centuries
ago and initially used mainly for grinding grain. The great advantage of traditional wa-
ter mills is that they can be constructed from local materials, and are easily maintained.
They are used around the world: In the Himalaya and Hindu Kush, for example, about
200,000 grind grain in mountain villages (Rijal 1999). A more recent innovation is up-
grading these traditional mills to provide electricity. The simplest method is to fix a bi-
cycle wheel to the grinding stone, so that as the stone rotates, the wheel can drive a belt
to charge a battery using an alternator; again, all the components are locally available
(Eagle and Olding 2001). To produce more electricity—and also to mill grain—turbines
can be installed in streams and rivers. Simple and relatively inexpensive systems are
now widely available (Agarwal 2006). The greatest challenge to making them econom-
ically viable is to ensure that the electricity, generated 24 hours a day, is used not just
in the evenings for lighting and television, but also during the day to promote the local
economy—for example, for small-scale industries such as mechanical workshops, pro-
cessing agricultural products, handicrafts, and telecommunications. In areas with many
tourists, the electricity can be used for cooking, decreasing demands on local forests for
firewood.