The Fernheizwerk was the heat and power generating plant providing power to the entire Industriehof area, from the SS Kanteen further to the south, to the Krupp factory and offices to the far north. Construction on the Fernheizwerk by Jewish prisoners can be seen on the Yad Vashem's Bauleitung (construction management) photo album. Work was carried out in winter time using sometimes the most primitive of tools to dig large channels in the ground to lay pipes. The plant also provided power and heat to Auschwitz camp I and the SS bakery and water plant further to the south west.
The building is still largely intact and can be seen today on the former Tobacco Monopoly rail line by the extension to Hotel Olecki. Many of the internal features are still original such as the framework and inner walls.
Information about sources we used while researching the industrial zones of Auschwitz you can find here.