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No, country X did NOT just run entirely on wind.

June 03, 2017 · 2 min read

There’s a lot of misleading information about renewable energy. Take for example this news article (and there’s a lot more):

(independent.co.uk) Denmark runs entirely on wind energy for a day.

On the surface it seems to make sense: Denmark produced more wind power than it consumed, therefore it ran entirely on wind energy. Right?


A very windy day in Denmark on the 22nd of February 2017 at 19:00 CET. Taken from the electricityMap App

Wrong. Why? Because Denmark wasn’t able to turn off their other power plants (see figure). If you can’t turn coal plants off, well, then they are still producing electricity, burning coal, and emitting CO2.

In fact, those coal power plants contributed to 65% of Denmarks electricity-related CO2 emissions. At a time where Denmark supposedly “ran entirely on wind energy”, 36% of its electricity came from fossil-fuel-based power plants.


The forgotten coal production actually represented 65% of emissions. Taken from the electricityMap App

Electricity produced from fossil fuels and from wind inevitably gets mixed up in the grid — you can’t un-mix them after. This means that as long as you have coal, gas and oil power plants running, you are effectively using electricity from fossil fuels! Unfortunately, you can’t selectively export the dirty stuff to our neighbours, and keep the clean electricity to yourself.

We focus on the wrong thing

The problem with comparing renewable production to consumption, is that it completely misses the other power plants generating surplus power.

The climate challenge is however simple: we need to reduce emissions, thus close fossil-fuel-based electricity production.

Instead of focussing on how much renewable we produced, let’s focus on how much CO2 we emit or on how many coal or gas power plants we closed.

To sum up:

  • Comparing wind production to a country’s consumption doesn’t give the full picture
  • Instead, let’s focus on whether or not fossil-fuel-based plants actually were closed

This will lead us to a much more interesting question: why didn’t we close the coal, gas and oil power plants during a time where country X supposedly “ran entirely on wind energy”.

Olivier Corradi

Written by Olivier Corradi
Founder @ electricityMap, CEO
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