In 2008 Ericsson exceeded its target to lower energy use in a 3G base station by 50 percent compared to 2005 levels. Later this year it will introduce future targets.
As the need for power decreases, the use of renewable energy, like solar and wind power, becomes more viable. A base station that needed 200 square meters of solar panels five years ago, today needs 50 square meters, according to Ericsson.
Wind and solar power have advantages and disadvantages. Wind is more efficient, if you find a spot with enough speed and wind occurrence, according to Blau.
But there is more data -- about where the sun shines, and for how many hours -- about where you can use solar power, according to Ericsson's Linda Ekener Magi, marketing manager, Communications Expander.
At the same time, solar-power technology has disappointed in recent years -- it isn't evolving as fast as Ericsson and Vodafone had hoped.
In the end, considerations about lowering carbon-dioxide emissions and using renewable energy come down to cost. Currently any Vodafone investment needs a pay-back time of two years at the most.
Vodafone Germany was the first operator to upgrade its network to support BTS Power Savings. "I am keen to get it in other networks as well, but the software upgrade is really expensive," said Blau.
From a technical standpoint, there are also challenges. The best way to decrease carbon-dioxide emissions is to use fewer base stations. But building a network with high data speeds requires using more base stations.
Vodafone acknowledges the paradox.
"The radio guys want to build the best network in the world, and I want to lower energy use, so we'll have to try to find a compromise," said Blau.