Embodied energy

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Embodied energy[1] on Mars is the measure of all the energy required for the preparation of products or services. It allows for a useful comparison of various materials that can be produced in-situ for the construction of martian settlements. The following table includes is cradle to gate: From mining to production to a finished product at the gate of the plant.

In common materials (from Wikipedia, partially adapted to Mars)

Selected data from the Inventory of Carbon and Energy ('ICE') prepared by the University of Bath (UK)

Material Energy MJ per kg Density kg /m3 Mars notes Source
Water 0,5 1000 Melting or condensing from atmosphere ML
Compressed Regolith Blocks (CRB) 0,5 2000 5% cement ML
Hydrogen 180 Electrolysis of water, 80% efficiency, this also produces large amounts of Oxygen ML
CO2 4 1 Work of compression and liquefaction ML
Propellant (CH4) 127 This includes the energy to produce the corresponding Oxygen, atmospheric compression and hydrogen electrolysis. ML
Food 1580 900-1000 This also includes biomass, needs to be refined ML
Solar cells[2] 2088 Silicon cells, not installed.
Aggregate 0.083 2240 This is the energy required to crush and sort the aggregate that is used for concrete production or road building
Concrete (1:1.5:3) 1.11-2 2400 This is for M20 concrete, slightly better than average concrete
Bricks (common) 3 1700
Concrete block (Medium density) 0.67 1450
Aerated block 3.5 750
Limestone block 0.85 2180
Cement mortar (1:3) 1.33 Cement with sand mixed in
Steel (general, av. recycled content) 35 new

20 recycled

7800 From Iron, mining and foundry included, as a finished product. Recycled value is about 60% recycled.
Stainless steel 56.7 7850 From Iron, Meteoritic iron might require much less energy. Type 304.
Nickel 165 8908
Timber (general, excludes sequestration) 8.5 480–720 Unlikely, at first. Bamboo glued structural elements might provide similar services
Glue laminated timber 12
Cellulose insulation (loose fill) 0.94–3.3+300 43
Glass fibre insulation (glass wool) 28 12
Rockwool (slab) 16.8 24
Expanded Polystyrene insulation 88.6 15–30
Polyurethane insulation (rigid foam) 101.5 30
Straw bale 0.91 100–110 Probably much more expensive on Mars, depends on the value of biomass
Mineral fibre roofing tile 37 1850
Clay tile 6.5 1900 Clay deposits are available
Aluminium (general & incl 33% recycled) 155-220 2700 Alumina is common, but perhaps not in concentrated ores
Medium-density fibreboard 11 680–760
Plywood 15 540–700
Plasterboard 6.75 800
Gypsum plaster 1.8 1120
Glass 15 2500 Primary glass production. Toughened glass reaches 23 MJ/kg
PVC (general) 77.2 1380
Vinyl flooring 65.64 1200
Terrazzo tiles 1.4 1750
Ceramic tiles 10-12 2000
Wood 1200-1500 600-800 Similar to food ML
Wool carpet 106 Sheep on Mars?
Wallpaper 36.4
Vitrified clay pipe (DN 500) 7.9 Might be interesting for many uses
Copper (average incl. 37% recycled) 42-140 8600
Lead (incl 61% recycled) 25.21 11340
Ceramic sanitary ware 29
Paint - Water-borne 59
Paint - Solvent-borne 97

Plastics, for example, have a high value of embodied energy and therefore are not the best choices for construction materials, of other choices are available. Note, energy of plastic feedstock may not be included.

Aluminium requires much more energy than Steel or iron and therefore is less likely to be used for construction on Mars.

The values for wood products and other biological products in the above table do not include embodied solar energy.

With embodied solar energy:

Food: At an average yield of 3 tonnes per hectare (conservative) embodied energy is about 1580 MJ/kg. Needs to be checked in detail

Wood: At 4 tonnes per hectare for bamboo, embodied energy is about 1200 MJ/kg. Work to transform it into a usable product should be added from table above.

Embodied energy in solar cells (Wikipedia)

Including cell manufacture, supports and structure. PV cells require very high amounts of energy to manufacture and are likely to be more economical to transport from Earth in the earlier stages of a colony. However, in the long term they produce far more energy than they embody, so solar can be envisioned as a sustainable energy production method for Mars.[2]

Photovoltaic (PV) Cells Type Energy MJ per m2 Carbon kg CO

2 per m2

Monocrystalline (average) 4750 242
Polycrystalline (average) 4070 208
Thin film (average) 1305 67