Coal and gas power plants
Coal- and gas-fired power plants will continue to form the backbone of our electricity supply in the decades to come. Energy consumption is on the up worldwide and, despite all the progress made in renewables, highly efficient, fossil-fired power plants will have to ensure dependable power supplies in the foreseeable future. In Germany, extensive replacement investment is still outstanding: on age grounds, power plants with a capacity of over 40,000 MW must be renewed by 2020.
The great need for new power plant capacities can only be met, as things stand today, by energy-efficient coal- and gas-fired power plants. This among other things also to reduce CO2 emissions which, besides the undenied importance of climate protection, have become a significant cost factor since emissions trading started. For power plants of recent date, this means: more output coupled with falling emissions and less resource consumption. RWE is making in-depth efforts to solve this conundrum. Research and development play a crucial role here as innovation driver. The scene has been set, and striking successes have already been scored.
RWE's new lignite-fired power plants work with the most modern plant engineering in the world. They reach record-breaching efficiencies of some 43%.
Using the most modern technologies, RWE is also trimming new hard coal-fired power plants to an efficiency of 46%, well above the Europe average of approx. 36%. Even more efficient are combined-cycle gas turbine plants (CCGT) that back a fossil energy source, natural gas. With a downstream CHP plant, they reach energy-utilization rates of up to 80%. Where electricity-only is generated, net efficiency is up to 58%.
More efficiency and less emissions
In the long run, the researchers are pursuing a vision that could become reality in the next decade: the climate friendly power plant. The prerequisite is that this so-called CCS (carbon capture and storage) technology is put on a sound basis. Much is already technically possible today. In addition, however, a Europe-wide legal and regulatory framework must be created to offer security for investment and promote acceptance of the technology. On the road there, several innovations are already close to market maturity. Take the example of lignite-fired power plants: RWE proposes to boost efficiency yet again by several percentage points in future plants thanks to intelligent drying of raw lignite. Hard coal-fired power plants are a case in point: here, companies in the energy sector are working on an increase in the steam parameters and are jointly testing the components and materials for a so-called 700°C power plant. This is likely to cross the 50%-efficiency mark in converting coal into electricity.
Developed yesterday, in use today: State-of-the-art technology places RWE's power plants among the most modern in the world.
It may be a dry subject, but it is still exciting: fluidized-bed drying with internal waste-heat utilization forms the basis for the lignite-fired power plants of tomorrow.
Increasing the steam parameter
700°C power plants will make the conversion of coal into electricity more efficient. At a pilot plant in Gelsenkirchen, RWE engineers, together with partner companies, are trialling the power plant components for this temperature level.
The expansion of power generation based on renewables means that increasing volumes of fluctuating energy are fed into the power grid. To counteract this effect, it is of particular importance that research and development are geared towards developing new solutions for a flexible operation of fossil-fired power plants. This will allow fossil plants to support the increased use of renewable resources and - as a partner to renewables-based generation - ensure an affordable and secure energy supply in Germany over the long term.