With the energy crisis, the world telecommunications also are required to support government programs energy efficient electricity, plus more sukarnya install new power PLN, especially outside Java.
But alternative energy sources are solar and wind energy. One operator in Indonesia that has been using solar energy as a source of BTS is Axis, as quoted from vivanews.com.
44 photovoltaic panels used to generate the total electricity 8kW at the sunny weather. Solar energy captured kamudian stored in batteries that will be the source of energy during the night or cloudy weather. Axis claims that the system is muted and does not cause pollution.
I think, exemplary steps Axis and applied by other Opeartor. Other alternative technology is to use a turbine driven by the wind.