Difference between revisions of "Embodied energy"

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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 in plastic feedstock is included, although these are for feedstocks on Earth.  The feedstock energy on Mars is probably higher as it is all sources from methane.'''
 
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 in plastic feedstock is included, although these are for feedstocks on Earth.  The feedstock energy on Mars is probably higher as it is all sources from methane.'''
  
Aluminium requires much more energy than Steel or iron and therefore is less likely to be used for construction on Mars. However, both steel and aluminium production on Earth uses coke, that embodies significant energy that is not counted in the evaluation made for Earth but would need to be added for Mars TBC.
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Aluminium requires much more energy than Steel or iron and therefore is less likely to be used for construction on Mars. However, both steel and aluminium production on Earth uses coke, that embodies significant energy that is not counted in the evaluation made for Earth but would need to be added for Mars . ''TBC.''
  
 
'''The values for wood products and other biological products in the above table do not include embodied solar energy.'''  
 
'''The values for wood products and other biological products in the above table do not include embodied solar energy.'''  
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==Embodied energy in solar cells==
 
==Embodied energy in solar cells==
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.<ref name=":0" />
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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.  On Erth soalr cells produce their embodied energy in about one year or less. Mars should require 2+ years due to the lower solar constant. <ref name=":0" />
 
{| class="wikitable"
 
{| class="wikitable"
 
|'''Photovoltaic (PV) Cells Type'''
 
|'''Photovoltaic (PV) Cells Type'''

Latest revision as of 16:44, 7 February 2021

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 is cradle to gate: From mining to production to a finished product at the gate of the plant. A martian settlement will also use operational energy, for moving, heating and cooling the products. Most food product information does not include the solar energy required for growth but only the energy required for food production, fertilisation and transformation. Recycling and energy recovery can reduce embodied energy significantly.

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/kg Density kg /m3 Mars notes Source
Water 0,5 1000 Melting or condensing from atmosphere 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
Nitrogen 1 1 Absorption using fibes and pressure differentials[2] ML
Ammonia NH3 55 0,73 16% of the mass of protein is nitrogen. Hydrogen need to be produced by electrolysis, then combined with compressed atmospheric nitrogen and turned into ammonia via the Haber-Bosch.
Propellant (CH4) 127 This includes the energy to produce the corresponding Oxygen, atmospheric compression and hydrogen electrolysis. The residual energy density of methane is 53,6 MJ/kg. ML
Food 1580 900-1000 This also includes biomass, needs to be refined ML
Aggregate 0.083 2240 This is the energy required to crush and sort the aggregate that is used for concrete production or road building
Compressed Regolith Blocks (CRB) 0,5 2000 5% cement ML
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
Glass 15 2500 Primary glass production. Toughened glass reaches 23 MJ/kg
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.
Aluminium (general & incl 33% recycled) 155-220 2700 Alumina is common, but perhaps not in concentrated ores
Copper (average incl. 37% recycled) 42-140 8600
Lead (incl 61% recycled) 25.21 11340
Nickel 165 8908
Gold 310000 19300
Platinum 190000 21447
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
Medium-density fibreboard 11 680–760
Plywood 15 540–700
Plasterboard 6.75 800
Gypsum plaster 1.8 1120
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
Ceramic sanitary ware 29
Paint - Water-borne 59
Paint - Solvent-borne 97
Carbon fiber composite[3] 800 1800-2000
Solar cells[4] 2088 Silicon cells, not installed.

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 in plastic feedstock is included, although these are for feedstocks on Earth. The feedstock energy on Mars is probably higher as it is all sources from methane.

Aluminium requires much more energy than Steel or iron and therefore is less likely to be used for construction on Mars. However, both steel and aluminium production on Earth uses coke, that embodies significant energy that is not counted in the evaluation made for Earth but would need to be added for Mars . TBC.

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. Embodied energy tables for food on Earth do not include solar power but only include energy used for fertiliser production, food production and transformation. This may add about 1o-20 MJ/kg to food.

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

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. On Erth soalr cells produce their embodied energy in about one year or less. Mars should require 2+ years due to the lower solar constant. [4]

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

Embodied energy in consumer goods

From the University of Calgary Energy education website. For the table below the values are an aggregate of all of the energy within the objects, so there is no mass unit included, rather it is the amount of energy in the entire object.

Embodied energy in objects
Embodied energy (MJ/functional unit)[5][6]
Hair dryer 79
Coffee maker 184
LCD monitor 963
Smartphone 1,000
PC tower 2,085
Washing machine 3,900
Laptop 4,500
Refrigerator 5,900
Digital copier 7,924
Cell tower 100,000

References

  1. https://en.wikipedia.org/wiki/Embodied_energy
  2. "A Sustainable Approach to the Supply of Nitrogen". Parker Hannifin, Filtration and Separation Division. Retrieved 5 March 2015
  3. Sunter, D.A., Morrow III, W.R., Cresko, J.W. and Liddell, H.P., 2015, July. The manufacturing energy intensity of carbon fiber reinforced polymer composites and its effect on life cycle energy use for vehicle door lightweighting. In Proceedings of the 20th International Conference on Composite Materials (ICCM), Copenhagen, Denmark.
  4. 4.0 4.1 https://greenchemuoft.wordpress.com/2017/12/12/embodied-energy-and-solar-cells/
  5. N. Duque Ciceri, T.G. Gutowski, and M. Garetti. (Accessed September 13, 2015). A Tool to Estimate Materials and Manufacturing Energy for a Product [Online], Available: http://web.mit.edu/ebm/www/Publications/9_Paper.pdf
  6. B. Raghavan and J. Ma at UC Berkeley. (Accessed September 13, 2015). The Energy and Emergy of the Internet [Online], Available: http://conferences.sigcomm.org/hotnets/2011/papers/hotnetsX-final56.pdf