Heizkraftwerk Köln-Niehl

From 2003, a combined cycle gas turbine plant (Plant II) was built around a Siemens V94.3A gas turbine with a downstream heat recovery steam generator, delivering roughly 145 MW of electricity plus 370 MW of district heat. Cooling and district heating systems were largely carried over from Plant I. Rhine harbour water handles cooling under normal conditions; the wet cooling tower only kicks in during warm summers or low river levels, when legal limits on Rhine water temperature would otherwise be breached. A second unit, Niehl 3, entered trial operation in late September 2015 and was officially inaugurated in September 2016.

Alstom served as general contractor, supplying an GT26 gas turbine among other components. The unit is rated at 450 MW electrical output and can extract 265 MW of district heat. Electrical efficiency stands at 60 per cent; fuel utilisation rises to up to 88 per cent when feeding the district heating network. Niehl 3 can ramp from standby to full load in under 15 minutes and operates across a range of 20 to 100 per cent of rated capacity. It is connected to Amprion's 380 kV grid and RheinNetz's 110 kV network.

In June 2023, Rheinenergie announced plans to build a 150 MW heat pump directly adjacent to the plant — which would make it the largest heat pump in Germany at the time. Rhine water will serve as the heat source; the pump will feed into Cologne's district heating network and is calculated to supply around 30,000 households. MAN Energy Solutions will deliver the unit, with commissioning targeted for 2027.