PV generator as cover for landfill site

The use of abandoned lignite mines and former landfill sites as locations for renewable energy installations is nowadays a preferred method for the further use of these areas. But the authorities in Lippe are going one step further: they have installed photovoltaic generators on the disused landfill sites at Dörentrup and Hellsiek; these not only produce green electricity from sunlight but also act as covers for the landfill. The installation is the first of its kind in Germany to combine these two functions.

The Dörentrup landfill site has not functioned as a waste disposal facility for a long time. Like many other facilities in Germany, it was closed at the end of the 1990s, after the quantity of waste to be sent to the landfill drastically reduced with the coming into force of the Closed Substance Cycle Waste Management Act in 1996. Following the closure, the Abfallbeseitigungs-GmbH Lippe as landfill manager and the Lippe Energie Verwaltungs-GmbH (made up of the municipal utility companies of Bad Salzuflen, Detmold and Lemgo and the Lippe District) jointly had the idea of using the abandoned landfill area for the expansion of renewable energies. At the same time, a solution was being sought for reducing the incidental seepage of rainwater on the landfill site, which had to be dealt with extensively and cost-intensively because of the pollutants it contained.

Engine for progress:

  • First installation of a PV landfill cover
  • Annual savings of 6,300 tonnes CO2
  • Reduction of quantity of seepage water by 50%
  • No increase in waste charges because of the smaller volume of seepage water
  • Non-permanent covering gives possibility of future landfill renaturation.

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Photo: Wolfgang Wienkemeier

The PV installation on the Dörentrup landfill site has a surface area of 37,150 square metres. It generates an average of 4 million kilowatt-hours of emission-free solar electricity per year.

Using available landfill sites for PV installations

The PV system installed in 2011 on the Dörentrup landfill site indeed combines both requirements: a photovoltaic generator which is the first in Germany to also act as a cover for landfill. This not only enabled the region’s share of renewable electricity generation to be increased, but also at the same time the quantity of incidental seepage to be markedly reduced. On top of that, the use of a cover preserves the possibility of renaturation of the landfill site later on, which would not have been so easy if there had been a permanent cover.

After the dual function of the installation had been successfully tested, the concept was transferred in 2016 to the Hellsiek landfill site nearby. Together the two installations generate peak output of 15 megawatts and provide an average of 12 million kilowatt-hours of solar electricity every year. This output is sufficient to supply around 3,400 four-person households with electricity for a year. And by converting solar energy into electricity, the two installations save around 6,300 tonnes of CO2 per year.

Less seepage water through reduced rain penetration

The PV installations have a watertight substructure which collects any rainwater and diverts it into appropriate drains so that it does not seep through the landfill. In this way the PV installation also acts as a landfill covering. This reduces the quantity of polluted seepage water on the landfill sites by nearly half. For the residents of Lippe District this means a small reduction in their waste disposal charges, since less seepage water needs to be expensively treated.

Photo: Anne Lehmeier

“Photovoltaic installations as a landfill cover protect the climate in several ways: first by generating renewable electricity, secondly through saving energy used in treating the seepage water, and thirdly by allowing the possibility of future renaturation of the landfill site.”

Berthold Lockstedt, ABG Lippe – Director

Partners and sponsors

  • Abfallbeseitigungs-GmbH Lippe
  • Lippe Energie Verwaltungs-GmbH