We visited the inside of the Salmisaari combined heat and power plant (CHP). It extends 126 meters below sea level, and 150 meters in the sky, and it’s energy reaches the whole of Helsinki. The visit into the belly of the beast, includes rows of gigantic thermal tranducers, boilers, coal grinders, the view from the rooftop and Europe's largest vertical lift conveyor system.

Over the course of a year, approximately 600,000 tonnes of coal is ground into a fine dust and burnt to produce 700 GWh of electricity and 1500 GWh of heat.