Google has unveiled a world-leading internet initiative in Christchurch this afternoon - balloon powered internet.

The project comes from the internet giant's special X division - the brains behind driverless cars and Google Glass. Though it may sound far fetched, Google says launching special balloons carring computer equipment can quickly create a high speed internet infrastructure.

It could stretch internet coverage over remote parts of the world - and also be deployed to keep internet going during a natural disaster.

This is partly why Google chose Christchurch to launch the initiative, in tribute to the city's struggle in the wake of the 2010 and 2011 quakes.

Prime Minister John Key unveiled the technology, codenamed Project Loon, from the Air Force Museum in Wigram.

Google's lead engineer for the project, Mike Cassidy, said they aimed to build a "ring of balloons" flying around the globe on stratospheric winds, providing internet access to the earth below.

"It's very early days, but we've built a system that uses balloons, carried by the wind at altitudes twice as high as commercial planes, to beam Internet access to the ground at speeds similar to today's 3G networks or faster," he said.

The balloons are solar powered, tracked by GPS and even equipped with a self-destruct system and parachute if they need to come down.

One of the founders of the project, Richard DeVaul, said the balloon internet was "green technology".

"All of the energy is renewable. The balloons won't be visible from the air and they won't interfere with airplane systems. We've gone out of our way to make sure they're highly visible and easy to track."

The balloons currently have a lifetime of a few weeks, but DeVaul believed in future they could last hundreds of days.

DeVaul said Project Loon grew out of huge connectivity problems worldwide.

"Two thirds of the world - 4.8 billion people - still don't have the internet. It's not that we don't know how to provide internet access, it's how to provide it over a large area in a cost effective way for everybody in the world," he said.

"It's not just the far reaches of the world that don't have the internet. Parts of New Zealand don't either. This is a crazy idea but we might be able to do it."

Across Canterbury, 50 people will be testing the balloons in the coming weeks. If successful, Google will look at taking the balloons from a prototype to a working technology.

Google is also hosting a free "Festival of Flight" event for the public from the Air Force Museum in Wigram from 10am tomorrow. The technology used in Project Loon will be available to be viewed by the public and some of the Google team will be at the museum to answer questions.

QUICK FACTS

● The balloons are filled with helium, run by solar power and are about 15m in diameter when inflated.

● Technicians can control the movement of a balloon by shifting them up or down on different air currents. A machine on the balloon allows air in and out, controlling altitude.

● The balloons use antennae to connect to the internet via ground stations on the earth. They can then transmit the internet via their antennae within a 40km diameter.

● Users have aspecial antenna, which will connect to the internet of any balloon flying overhead.

● The balloons drift through the stratosphere connecting with any ground station and beaming internet to any user's antenna which they come across.

● Each balloon can provide internet on the ground to an area of over 1200 square kilometers.

● The balloons cannot stay in one place, so in the future the idea would be to have so many balloons in the sky that coverage is constant.

● The balloons currently have an expected life-span of a few weeks but future technology could see them last for 100s of days.

● The balloons are tracked by a GPS system and a transponder so air traffic control know where they are at all times.