The calorific value lies at 7.8 to 10.5 MJ/kg, half that of firewood, necessitating three times the fuel tonnage of hard coal (27 - 33 MJ/kg) in power generation.
Abundant lignite deposits lie only a few hundred feet below the ground and are readily extracted by imposing bucket wheel surface excavators, some heavier than the Eiffel Tower (10,000 tons). On average, six times as much clay and sand must first be removed.
Suez Canal excavation every 3 weeks
Mining 175 million tons of lignite per year therefore becomes comparable to excavating the original Suez Canal (74 million cubic meters) every three weeks. That rate would be accelerated by energy intensive carbon capture and storage (CCS) technologies for circumventing the ETS. Superseding nuclear power by lignite generation would require even greater mining expansion, particularly if the inherent CO2 emissions were likewise to be captured and sequestered in distant saline aquifers.
To heavy for the export
Geological accessibility makes lignite Germanys least expensive fuel at 1.1 euro/GJ, about $1.70/MBtu, only a third the cost of imported coal. The low energy content precludes it from being profitably exported, effectively stabilizing domestic prices.