A phone made of recycled materials and a transmission tower that uses 50 percent less energy were two of the green technologies on show at the Mobile World Congress in Barcelona this week.

The environment was top of the agenda in the opening keynote session, where Rob Conway, CEO of the GSM Association, characterized mobile communications as an energy-saving alternative to flying or driving. But he acknowledged the downsides, saying, "We must, as an industry, do something about reducing energy consumption, and support renewable energy and recycling."

The GSM Association is using its development fund to support a number of technologies with benefits for the environment, he said, including green energy sources for off-grid base stations. These include a generator powered by waste vegetable oil, developed by Ericsson, and in Namibia the creation of a wind-powered base station, he said.

"The environmental results have been very encouraging. We are sharing these initiatives," he said.

Olli-Pekka Kallasvuo, president and CEO of Nokia, preferred to start with the bad news.

"Our current model of development is not sustainable. In many ways we are living beyond our means. As much as technology fascinates us and inspires us to do more things, something has to change," he said.

He wants the industry to make more efficient use of materials and to recycle its waste, to optimize transportation and logistics, and to design for energy efficient operation.

From his pocket he then produced "Remade," a concept phone manufactured mostly from recycled materials and designed to consume less energy in production and operation than existing phones. The case is made from recycled aluminium drinks cans, the rubber keyboard from old car tires, and plastic parts from recycled drink bottles.

"It's only a concept. I cannot make a phone call with it yet," he said, dashing the audience's hopes of picking one up from the Nokia stand later.

Wang Jianzhou, chairman and CEO of China Mobile, also had recycling and energy conservation on his mind.

The company is promoting simpler packaging for the phones it resells, with the goal of saving around 57,000 cubic meters of logs annually, he said.

It is also looking for ways to reduce the electricity consumption of the 300,000 base stations in the company's network, he said.

The IDG News Service is a Network World affiliate.