At the Garzweiler open-cast mine, RWE is planting a total of 160,000 new energy plants on two recultivation areas.
Silphium perfoliatum is to be tested as an alternative raw material for the generation of biogas. The aim is to use the plants at RWE’s biogas power stations in Neurath and in future also in Bergheim-Paffendorf and to compare the gas yield and biogas quality with those of other energy plants. In addition, tests will be carried out on the amount of care the plants need, surface yield as well as the environmental added value of the Silphie plant.
The Kölner Büro für Faunistik will accompany the three-year research project. Dr. Hans Bünting, Managing Director of RWE Innogy GmbH: “In future, we want to break new ground when it comes to supplying our biogas plants. Testing new raw materials is key in this regard. As was the case when we expanded wind power in the Rhenish region, we are again working very closely with our sister company RWE Power and can thus leverage new potential.”
Matthias Hartung, CEO of RWE Generation and RWE Power added: “In collaboration with RWE Innogy, we have set up an area bigger than eight football pitches on our recultivated open-cast area to test our new energy plant. In the future, the plant is to make a contribution towards enabling renewables to provide secure supply.”
Silphium perfoliatum is primarily of interest as an energy plant due to its adaptability to dry locations. By contrast with maize, for example, it can draw moisture not only from the ground, but also from its cup-shaped leaves. It also provides a high biomass and biogas yield that is comparable to that of energy maize. Silphium perfoliatum originates in North America, where it grows in climatic conditions comparable to those of central Europe. It is therefore easy to cultivate in Europe too and can be harvested regularly over a period of at least 10 years. This allows the Silphie plant to provide additional benefits compared to other energy plants such as maize. The leaves provide shade for the ground so that from the second year of cultivation, no herbicides are required. There is also hardly any ground erosion. Due to its long period of bloom from June to September, it also provides nutrition to many visitors such as bumble bees, bees and hoverflies.
The two companies already set up a smaller test area in 2010 at the Garzweiler open-cast mine. Around 12,000 Silphie plants are already growing in this recultivation area. The substrate harvested from this area has been used at RWE’s biogas plant at Neurath in the past two years. “We are confident that the Silphie plant will establish itself as a new energy plant in the long run”, said Bünting. “The tests at our biogas plant in Neurath are promising. Now we will expand the testing process to the 160,000 newly planted Silphies at our planned biogas station in Bergheim-Paffendorf.”
Additional test location for new energy plants in Saxony-Anhalt
In addition to the areas in the Rhenish region, RWE Innogy also has a further test location for new energy plants. In Saxony-Anhalt, close to the community of Gütergkück, 120,000 Silphie plants have been growing since 2010 on around three hectares of land. Last week, another five hectares was planted with 200,000 young plants. The new energy plants will be used at RWE’s biogas power station in Güterglück.