The Danes like to think of themselves as green. Denmark is home to the world's largest wind turbine manufacturer, Vestas. And today, the giant state-owned energy company, Dong Energy, opens the world's largest windfarm.

But the Danes have a dirty secret. For Dong Energy, while greening its image at home, is busy building coal-fired power stations elsewhere in Europe. First in Germany, and now in Scotland.

We in the rich world are used to the idea of our big companies dumping their dirty and anti-social industries on the poor countries. But now European companies are doing the same to us. Rather as if Scotland were a banana republic somewhere in the developing world, it is the recipient of Dong "outsourcing" the dirty end of its energy portfolio.

Dong, which began as a North Sea oil and gas company before buying the country's electricity utilities, trades on its green image in a country that likes to be thought of as green. Its website announces that the company is "part of the solution" to climate change, and it lovingly pictures its efforts to "move energy forward" on a sea of wind turbines.

Today Denmark's king and prime minister will both be on hand as the record-breaking 209-MW Horns Rev 2 windfarm opens off the west coast.

But Dong also sees itself as a diverse energy provider, and wants to grow in the coal business, too. It would be unlikely to get permission to build a new coal-fired plant at home, however. The Danish government last December proposed that the EU should limit carbon emissions from new power plants to 500g per kilowatt hour – far too low to accommodate a coal-fired plant.

So, what it cannot do at home, it is intent on doing abroad. It is planning to build a giant 1600MW coal-fired plant at Greifswald in northern Germany.

And now in Scotland, Dong is to take a 75% stake in a new joint venture with local company Peel Energy to build a similar behemoth at Hunterston, west of Glasgow.

It would be the first new fossil-fuel burning power plant in Scotland for 30 years – a real step backwards for the country that has pioneered wind power in Britain.

I have written about Scotland talking green and building for coal before. The Scottish Nationalist government is keen to end the country's reliance on nuclear power, and to that end they are covering the glens in wind turbines and dotting the coastline with coal-fired power stations. Dong's new Hunterston plant would be built next to a nuclear power station.

But Dong, like many coal companies, is keen to give the dirtiest fossil fuel a makeover. For instance, it says it will add some biofuels to the coal in the boiler to create a "super-efficient multi-fuel power plant". Both the German and Scottish plants will this way reduce emissions by 20-30% compared to conventional coal power stations, it says.

But sorry, it will still burn coal. Burning coal produces roughly twice the CO2 emissions of even another fossil fuel like natural gas. So that 20-30% cut still leaves it among the dirtiest plants around. WWF estimates the new plant's carbon emissions will be 6.9m tonnes a year. So it would still be outlawed by the proposed new EU rules.

The other greenwash favoured by coal-burners is to hold out the prospect that emissions will soon be cleaned up and buried under ground using carbon capture and storage.

Dong says the construction plans for the £2bn Hunterston plant "include the development of carbon capture and storage", but adds the caveat "once the CCS technology has been fully developed."

As I have written before, that's quite a caveat. By some counts, that day will not happen till towards the end of the plant's lifetime, if at all.

Dong Energy may be an efficient coal-burner. But dressing that accomplishment up as a green technology is greenwash. When it goes on the coal trail, Dong looks like part of the problem, not part of the solution.