Harnessing a festival experience to fight climate change


Flow Festival, one of the most esteemed music and arts festivals in Northern Europe, has been a staple of Helsinki’s urban culture for nearly two decades.

Last summer, Flow partnered with us to propel their sustainability efforts to new heights. Together, we transformed a part of the festival experience into an activation that raises money and awareness for the most defining megatrend of our time: Climate change.

Project Highlights

  • The first party to plant a forest: nearly 12K trees planted with pocket change
  • A sustainable innovation: custom made return kiosks, novel technology for real-time visualizations, Reaktor Backyard built with 100% recyclable materials
  • An entire festival experience, compensated: our goal of removing 7200 tons of CO2 from the atmosphere was met – and oveshot twice over

  • A prime example of how service design can create an impact through transforming an existing value chain

Starting Point

Festival experiences are about music, friends, summer nights – but, as temporary and village-like communities, they also provide a unique opportunity to experiment with new innovations for the circular economy and sustainable lifestyles.

Internationally recognized for a meticulously curated program and stellar festival area design, Flow Festival has also put a benchmark on the European festival scene by going entirely carbon neutral.

This year, we set out to prove a point: a small tweak in an existing value chain can create a big, positive impact. It’s music for friends, trees for the planet.

Our innovation taps into an anomaly in the Festival’s customer experience. For every drink, 1€ must be deposited for the container. Then, that euro has to be reclaimed in the most anticlimactic way.

Creative solution

Small act, big impact

In a magnitude of recent studies, reforestation has been proclaimed to be the most effective way to fight climate change.

By creating alternative return kiosks, we turned every drink into a rewarding act of planting a tree. The deposits from the return kiosks were directly channeled into donations for The Finnish Association for Nature Conservation reforestation projects.

For every container donated, one tree was planted, removing one tonne of carbon dioxide from the atmosphere over its lifetime. We set the goal to offset the daily CO2 emissions of all festival goers, for the entire three-day festival experience.

A key feature in rewarding festival-goers for making a choice for the environment was visualizing the impact of each donation in real time – at the spot and the campaign website.


Planting a tree, a how-to

Buy a drink

For every drink, 1€ must be deposited for the container.

Toast, down, dance

Empty the container. The harder you party, the more trees you plant.

Bring the container to a return kiosk

Find the nearest Reaktor return point and feed the container into it. No lines, no fuss.

Watch a tree grow

Observe on the screens as your donation ups the total tree count by one. Repeat.

The technology

We designed, built, and soldered together the smart return kiosks by hand. The solution’s infrastructure consisted of a small electronic circuit that detected drink containers sliding through a tube, and a computer that communicated the action and its impact to the donor.

The basic process was as follows: a donor put the can in a tube and it slid down. The can blocked the light path of a laser momentarily, and an LDR (Light-dependent Resistor) gained resistance. Raspberry Pi monitored the resistance change, and sent the event to the display to thank the donor. In addition, the message was sent to the Sensor API in the cloud and the Sensor API stored the event in the Database. A background process calculated daily summaries, updating the database every 3 minutes. The computer connected to the display polled the summary API every 5 minutes to display the updated donation numbers from all the other stations. The campaign website used the same summary API to fetch the summary numbers.

A single station infrastructure consisted of a Raspberry Pi, with a 4G USB dongle, a computer that got internet connection from the Raspberry via ethernet cable, a large display and 18 meters of electrical wire and 9 electrical components and several connectors, with around 100 hand soldered wire ends.


Small act, big impact

A forest, created as the result of dancing, laughing, loving, and toasting together.
A celebration of the power of the individual in making the world a better place.
And a party that removed the equivalent of five days of CO2 emissions in the lives of everyone that took part in the best city festival of 2019.

The success of activations like this goes to show that rethinking dated processes and challenging conventions are how the better options stick and prevail.

The math

1€ = 1🌲

One container donated, one tree planted

12 t

CO2 removed from the atmosphere

83 K

Flow visitors

5 days

In the life of all visitors, compensated

“The deposit donation idea helped us take our sustainability efforts to greater heights, involving our visitors in a meaningful way”

Milla Valjus, Marketing Manager at Flow Festival

Niclas Kristiansson

Executive Creative Director at Reaktor Creative

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