Modern power plant engineering

Niederaussem, 20 kilometres northwest of Cologne: Nine gigantic power plant units make this complex RWE's biggest energy location. Between them, they produce nearly 4,000 MW – enough energy for four million households. One of the giants in particular catches the eye: the "BoA" unit, 173 metres high and a milestone in fossil-based electricity generation. With an efficiency of 43.2% this "lignite-fired power station with optimized plant engineering" is about one third more efficient than conventional systems. A record value – and at the same time a clear avowal of the future viability of lignite-based power generation. 

Major progress 

Like many other new developments that RWE has been translating into practice for decades now, BoA, too, has its origins in tried-and-tested technology: electricity may still be generated according to the same principles as in conventional plants, but important further developments in specific plant components and process steps must be added. For example, pressure and temperature of the steam are significantly higher. Additional heat exchangers intercept some of the residual heat contained in the flue gases – and return it to the process of electricity generation. 

Reducing energy losses   

All process steps are dovetailed in such a way that energy losses in the power plant process are reduced to the technically and economically possible minimum. This makes better use of the deployed lignite, and efficiency rises with a corresponding fall in CO₂ emissions per kilowatt hour generated. All in all, this power plant type cuts environmental impact by two to three million tons of CO₂ per year. BoA Niederaussem was commissioned in 2003. RWE is currently building two more power plant units of this type, this time at Neurath, Neuss county. When these two new BoA units go live in 2011, they will be the most modern lignite-fired power plants in the world.

Optimally coordinated 

In other areas of fossil-based power generation, too, RWE makes use of state-of-the-art technology for even more efficiency and lower emissions. Modern natural gas-fired combined-cycle gas turbine plants (CCGT) with combined CHP systems reach a utilization rate of about 80%. Here, electricity and heat generation are optimally coordinated, which yields a definite plus in the way of efficiency. 

Efficiency leap 

While yesterday's research results are being used in today's practice, the next technology generation is already being in pre-commercial trials by RWE. Example lignite: planned power plants with coal pre-drying reach an efficiency that is up to four percentage points higher compared with BoA. Example 700°C power plant: here, RWE's engineers are working on a comparable efficiency leap in coal-fired power plants thanks to an increase in the steam parameters pressure and temperature. 

High investment 

In the coming years, RWE will be investing further amounts running into billions in the new-build and conversion of fossil-fired power plants. On the road toward less raw-material consumption and improved climate protection, Research and Development work is of great importance. For a number of projects and trials, RWE has recourse to special labs and test facilities. For instance samples are tested under real operating condtions in our power plants and the chemical and mineralogical properties of coal is being analysed in our own laboratories.

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