The honest bill: how much energy and water did it take to build Pinkoa with AI?

The honest bill: about 27 kWh, 100 litres of water and 9 kg CO2 to build Pinkoa

Building Pinkoa in public means showing all the numbers. Sales (still zero, we know), visitors, mistakes… and now the one nobody likes to talk about: how much electricity and water did it take to build a whole shop with AI?

Koa asked. Claude did the maths. Here's the honest bill for the first 11 days (25 Sep – 5 Oct 2026).

The honest bill: about 27 kWh of energy, about 100 litres of water and about 9 kg of CO2 to build Pinkoa in 11 days

The short version

  • Energy: about 27 kWh (somewhere between 20 and 35 kWh)
  • Water: about 100 litres (60–150 L, including the water power plants use)
  • CO₂: about 9 kg (7–12 kg)

That covers the AI agents that built the timer, wrote the blog posts, designed the merch, rendered the videos and posted to social media, plus the laptop that ran the automations and a share of the hosting.

Where the energy went

Bar chart: Claude agents about 22 kWh, laptop about 2.5 kWh, rendering videos and images about 1.5 kWh, hosting about 0.5 kWh

The big one is the AI itself. A single chat question is tiny, Google puts a typical text prompt at about 0.24 Wh, roughly a few seconds of a microwave. But Pinkoa wasn't built with single questions. It was built with long agent sessions: Claude reading and writing files, clicking through admin pages in a browser, rendering videos, checking its own work, and doing it all again every morning at 08:51. Independent estimates suggest one long AI coding session can use dozens of watt-hours, and a heavy day of agent work around a kilowatt-hour. Eleven busy days add up.

So… is 27 kWh a lot?

Bar chart: a German household for one week about 56 kWh, an electric car from Berlin to Hamburg about 49 kWh, building Pinkoa about 27 kWh, a fridge for two months about 24 kWh, 100 hours of streaming video about 8 kWh

Koa's verdict: it's roughly half a week of electricity for an average German home, or driving an electric car about 160 km. Some fun ways to picture 27 kWh:

  • about 270 kettles of tea (a full kettle is about 0.1 kWh)
  • about 350 hours of streaming video (the IEA estimates about 0.08 kWh per hour)
  • about 1,800 phone charges
  • or about 110,000 ordinary chat questions, which tells you how much heavier agent work is than a quick question

How thirsty was Koa's shop?

Bar chart: one cotton T-shirt about 2,700 litres, a full bath about 150 litres, one cup of coffee about 130 litres, building Pinkoa about 100 litres, a 5-minute shower about 60 litres

Data centres use water to keep their chips cool, and power plants use water to make electricity. Together that's roughly 100 litres for the whole build: somewhere between a shower and a bath. The plot twist: one cup of coffee has a bigger water footprint (about 130 L, from growing the beans), and a single cotton T-shirt needs around 2,500–2,700 litres, mostly to grow the cotton.

Which means, a little awkwardly for a shop that sells shirts: one Koa T-shirt uses far more water than building the entire shop. That's exactly why our merch is printed on demand. Nothing gets made until someone actually orders it, so nothing sits in a warehouse.

And the CO₂?

With a typical European electricity mix, 27 kWh works out to roughly 9 kg of CO₂, about what a petrol car puts out in 50 km. Not nothing, not dramatic. Good to know, and good to keep small.

How we're keeping Koa's footprint small

  1. One batch run a day instead of lots of little ones. Bigger, planned jobs waste less than constant restarts.
  2. No stock, no waste: merch is printed only when ordered, mostly by printers in Europe.
  3. Printables are digital: zero shipping, zero plastic.
  4. The timer runs in your browser. Once pinkoa.com is loaded, your Pomodoros tick away on your own device, no AI involved.

The fine print

These are honest, rough estimates, not a lab measurement. AI providers don't publish per-request energy numbers for every model, so we combined published figures (like Google's per-prompt numbers and the IEA's streaming figures) with independent estimates for AI agent sessions and our own logs of how much work was done. If better numbers come out, we'll update this post. That's the deal with building in public.

Sources: Google on the energy and water per Gemini prompt · Simon P. Couch: electricity use of AI coding agents · IEA: the carbon footprint of streaming video · co2online: household electricity in Germany · Water Footprint Network (coffee, cotton)

Shade of the day: Dusty Rose

Today's shade is Dusty Rose (#DCAE96), a soft, muted pink that looks like recycled card. It pairs nicely with brown kraft paper, green plants and black ink, and it's a lovely colour for a low-waste study desk.

Want to study the low-energy way? The free Koa study timer runs right in your browser. 25 minutes focus, 5 minutes break, no account needed.

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