Fire in the holes: Transforming mined out lands into solar plants

While most post-mining plans, especially for surface mines, calls for pits to be redeveloped into lakes or farm land, an increasing body of research and evidence shows that these ripped-up landscapes can be successfully transformed into clean energy gold mines—whose solar PV resource potential, unlike coal’s, is infinite. L. Michael Buchsbaum reports

The European Comission outlines transition of post coal mines into solar power plants (photo courtesy Buchsbaum Media)

New lives for old mines

A new study from the European Union’s Joint Research Centre (JRC) entitled Solar Photovoltaic Electricity Generation: A Lifeline for the European Coal Regions in Transition suggests that if solar PV systems were built on post-mined land, within existing mine boundaries and on rooftops in regions moving away from coal, the resulting solar energy would be roughly equivalent to the combined coal and lignite-fired generation capacity of all the power plants currently operating throughout the European Union.

Coal today is mined throughout 42 regions across 12 EU countries. Additionally, coal-fired power plants generate electricity for 21 member states—accounting for almost a quarter of the EU’s overall electricity production. Combined, the 248 operational coal power plants (as of February 2019) have a total power capacity of 152.5 GW.

However, if the EU is to abide by the Paris Agreement, coal emissions have to be reduced by more than 70% by 2040. Knowing this, in order to ensure a socially fair transition away from coal, the European Commission introduced the Coal Regions in Transition (CRiT) initiative in late 2017, of which this new analysis is a part.

Taking advantage of new solar radiation maps, and using spatial and other data developed by the European Commission, researchers came to the startling conclusion that if solar PV is deployed both on degraded mine lands as well as within mine boundary areas, their combined technical potential would add up to 62.2 GW with an anticipated production of 72.2 TWh per year of operation. However the full potential within the CRiT areas, including roof mounted PVs as well as available land, would reach 730.3 GW that could contribute a total 874.3 TWh, potentially replacing the total electricity output of the current coal power plants operating in the EU—which provide some 25% of the region’s energy (if sufficient flexible production and storage capacities are also added).

Costs, of course, are a consideration. Given that the competitiveness of solar projects “in general depends on local market conditions including competition amongst energy providers, policy stability, the regulatory framework and access to capital,” the authors do not explicitly estimate what building out such a massive new solar network would require. However, recent solar auctions in the 42 CRiT areas for larger PV arrays “resulted in prices as low as USD 45/MWh (EUR 40/MWh) in Spain up to USD 96/MWh (EUR 86/MWh) in Poland.”

Smaller scale rooftop installations have higher capital costs, which vary considerably in the European Union “between USD 1000/kWp (EUR 890/kWp) and 3000/kWp (EUR 2680/kWp). The variation is due to different market conditions, building codes and local regulations. In addition, the value added tax (VAT) can vary between 0% and 27%.”

Nonetheless, the authors (along with other studies) point out that once a PV plant is up and running, their marginal costs over 25 years—ie for fuel (free!) and maintenance, are close to zero. Additionally, PV produces no emissions, and their societal costs are also close to null in comparison to coal.

“We tried to be conservative in our findings, despite the fact that it’s already a big number,” said Dr. Arnulf Jäger-Waldau, one of the study’s authors, in an interview with But clearly “the land is available. The miners have already sacrificed it for firing power plants,” he said.

However, the study is only a potential analysis, cautioned Jäger-Waldau, “not sketch a roadmap for how to achieve a replacement of coal or to transition towards a 100% renewable plan,” as has been modeled by the Energy Watch Group and LTU University, IRENA and other think-tanks.


Using post-mining or reclaimed mine land for solar energy projects is particularly attractive simply because it transforms a future or existing liability, the mine pit itself, into a longer-term revenue generating site. This may allow operators to forestall some of the expensive decades-long obligations to restore, monitor and manage the post-mined site. Instead, the deployment of solar PV systems provides another opportunity to generate profits, which can be further enhanced by utilizing existing grid infrastructure, trained personnel and other synergies. Sweetening the deal, miners may even be eligible for various EU redevelopment grants too.

With good planning, portions of the site can be redeveloped for renewable power production in tandem with on-going mining operations–allowing operators to gradually phase-in the renewables. “If you make the right decisions ahead of time, then future solar generation at these sites is much more likely. Miners can re-develop their current plans so that as extraction winds down, the open pits can become more favorable for solar redevelopment,” said Jäger-Waldau.

Ripe for redevelopment are RWE’s infamous lignite mines west of Cologne where solar potentially could generate 12 terawatts hours (TWh/year) on land surrounding the mining sites and almost 5 GW (and 5 TWh/year) within the mined out areas as well. In other words, the solar potential of the region has the potential to exceed the capacity of the lignite plants currently operating there—with none of the negative impacts to the environment and public health. This is in contrast to the current post-mining plans which call for the giant Hambach and Garzweiler pits to be flooded over a 40-year period with water diverted from the Rhine River.

In much sunnier Greece, the new study finds that solar energy from within several pits there could generate over 11 TWh per year. Already roughly 20% of the nation’s entire energy generation capacity, taking into account PV’s full potential throughout Greece’s CRiT areas, research shows solar could actually produce far more than the entire fleet of filthy lignite plants that supplies roughly half of Hellenic electricity. One can only hope that Greek policymakers will take a long look at solar given that the nation in September has pledged to phase out coal by 2028.

Bleeding and cutting edge examples

Worldwide, coal-to-PV operations already exist. Examples include a 16 MW solar park in Visonta, Hungary that is situated on top of a lignite mine dump site; the 4 MW solar project built on a former coal mine in the German Saarland; and several solar parks floating on the surface of flooded mine pits in China. But much more is in the pipeline.

Late last year, Polish miner and electricity provider, Zespół Elektrowni Pątnów-Adamów-Konin SA said it will deploy a large scale PV plant at a depleted area of the extensive Adamów brown coal mine in Turek, in the center of Poland, potentially replacing the 600 MW coal-fired Adamow plant which is scheduled to close.

More recently, energy-giant Vattenfall, which operated many open-pits throughout Germany, has announced pilot plans to deploy PV facilities on coal mining sites across the country building upon lessons now being learned while developing integrated solar/wind/battery storage projects in the Netherlands.

Going forward, Jäger-Waldau believes that the largest challenge of adopting a coal to PV conversion strategy is not technical but mental. “What we have to do is increase awareness of this potential. And naturally, as more trials occur, that will help change more minds,” he continued. But at the end of the day, “the sun is there for us to use. We have the potential, the opportunity, the technical means and the knowledge. As we put the wasted land back together again, solar redevelopment is an elegant solution.”


L. Michael Buchsbaum is an energy and mining journalist and industrial photographer based in Germany. Since the mid-1990s, he has covered the social, environmental, economic and political impacts of the transition from fossil fuels towards renewables for dozens of industry magazines, journals, institutions and corporate clients. Born in the U.S., he emigrated to Germany and Europe to better document the Energiewende. He is also the host of The Global Energy Transition Podcast.

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