GreenHack — A sustainability hackathon

GreenHack / 2026 edition / The results are in

Big questions. Small footprint.

A sustainability hackathon / 42 Prague

90+ curious minds. Twenty-four hours. One question: can AI help us live within our planet’s limits? Here is what we built.

See projects Read the 2026 recap
A robotic hand and a hand formed from nature reach toward each other.
01 / HUMAN × MACHINEINK ON PAPER
24 hours 42 Prague Teams of 2–4 or solo

01 / The 2026 question

AI and Sustainability: Friend or Foe?

AI comes with an energy and resource cost. Can it help us save more than it consumes? Since 2021, we have brought people together to test their answers in practice.

5–6 June 2026 / 42 Prague / 90+ participants

02 / Challenges 2026

Real problems. Open minds.

Six starting points for useful work. Explore the 2026 briefs.

Explore all challenges ↗
  1. Grid Pulse Help power grid operators understand a changing electricity network and respond to emerging problems.
  2. Renovate Now Help apartment building owners agree on energy renovation by making costs, savings and financing understandable.
  3. BlackOut Prague Help communities coordinate people, resources and communication when a blackout disrupts essential services.
  4. Responsible Agents at Work Make workplace AI agents transparent, accountable and energy-aware while keeping people in control.
  5. AI Skill Bridge Help colleagues share practical AI skills so that tools, energy and human potential are used well.
  6. The Apartment EV Gap Make electric mobility practical for apartment dwellers who do not have their own charging point.

03 / Projects 2026

Built in a day. Worth a closer look.

Meet the three main prize winners of GreenHack 2026.

All projects ↗
  1. 1st place

    An AI copilot for the power grid

    Walking legs

    An AI assistant that helps power grid operators make sense of operational data and investigate emerging issues.

    2026 / Grid Pulse
    2,000 €
  2. 2nd place

    renovuj.me

    Tinkering Hyena

    A tool to help apartment building owners make shared decisions about renovation and energy savings.

    2026 / Renovate Now
    1,000 €
  3. 3rd place

    Does an EV fit your everyday life?

    IOC

    A practical assessment of EV suitability and charging options based on everyday mobility.

    2026 / The Apartment EV Gap
    500 €

GREENHACK / 2027

The next chapter.

Dates to be announced

2027 is taking shape. The date is not set yet.

Come with an idea, a team, or just a little curiosity. Let us know if you would like to be part of the next edition.

Ask for a 2027 update ↗

04 / LOW-WATT PAPER

This page travels light.

Local fonts. Dithered images. No tracking. Our footprint is part of the brief, too.

How we count ↗
42 PragueČEPSČeská spořitelnaBlackOut Prague