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by wumms 2566 days ago
A quick estimation about the environmental impacts (with data for Germany only) shows peat is at least 5-20 times worse in terms of surface destruction - I have no idea how to compare the ecological impact of removing a biotope vs. moving a town.

Lignite:

- thickness of a lignite bed 11-35m [0]

- surface destruction per metric ton: 220-700 cm² [0]

Peat:

- thickness of a peat layer 1,5-2m [0])

- surface destruction per metric ton [1]:

-- at least 3,850-5,130 cm² (using the same density for coal and peat)

-- 6,000-8,000 cm² (moist peat, 0.8g/cm³ [2])

-- 10,000-13,300 cm² (dried peat, 0.4 g/cm³ [2], considering the higher calorific value for peat [4])

-- at worst 12,000-16,000 cm² (dried peat, 0.4 g/cm³ [2])

[0] (Data from 2015 for German mining areas; page in German) https://www.umweltbundesamt.de/daten/flaeche-boden-land-oeko...

[1] There was no data for the surface destruction for peat in [0] so I estimated it using densities from [2]:

thickness lignite bed x surface destruction lignite x density lignite / density lignite / thickness lignite

e.g. 700 cm² x 11 m x 1.25 g/cm³ / 0.801 g/cm³ / 1.5 m = 8011 cm²

[2] https://www.wolframalpha.com/input/?i=peat+lignite

[3] https://www.engineeringtoolbox.com/fuels-higher-calorific-va...

[4] The gross calorific value for peat is 5-20 % higher than for lignite [2]-[3]; though I guess that does not exclude the energy needed for drying the peat.