Google says it’s used balloons to help “tens of thousands” of people get online in Peru after flooding hit connections in rural areas. It was an unplanned expansion of an ongoing experimental project.

Project Loon (which is technically run by Google parent company Alphabet) uses 49-feet wide helium balloons flying 12 miles above earth to carry wireless signals. Signals are sent on a chain bouncing between balloons and ground stations, which can be as much as 60 miles apart.

While the ballons fly in the stratosphere, above the most intense weather such as local winds, they are still vulnerable to major weather streams. That meant that for much of the past four years of testing the idea has been to have hundreds of balloons travelling around the world on a particular parallel with a large degree of redundancy to allow for individual balloons going off course.

Earlier this year Google said it had found a way to use machine learning that means balloons can better predict weather and thus change altitude to avoid being swept off course (or return to the preferred location). That makes it much more viable to use a few dozen balloons to give a reliable service in a specific area of the world.

Most of the testing to date has been aimed only at a few users. However, Google says it was testing in Peru earlier this year when several cities were hit by floods, so decided to open it up to a wider audience across an area similar in size to Switzerland.

Over the past three months, users have transferred around 160GB of data in total. While that doesn’t sound much, Google hasn’t said what speeds the users are actually getting. If people are simply using it for emails and other messaging, that’s a very different prospect to people trying to access media.