UEVs of Fuels and Some Common Products

UEVs result from emergy evaluations of processes. Given in Table 4 are UEVs for main nonrenewable energy sources and some common materials. In some cases, the

Table 1 Annual emergy contributions to global processes®

Input

Units

Inflow (units yr~1)

Emergy/unit (sej/unit)

Empower (E24sejyr1)

Solar insolationb Deep Earth heatc Tidal energyd

Total

3.93E24 6.72E20 0.52E20

1.20E4 7.39E4

15.83

aNot including nonrenewable resources.

bSunlight: solar constant 2 gcalcm-2 min-1 = 2 Langley per minute; 70% absorbed; Earth cross section facing Sun 1.27 E14 m2.

cHeat release by crustal radioactivity 1.98E20 Jyr-1 plus 4.74E20 Jyr-1 heat flowing up from the mantle. Solar transformity 1.2E4sej J-1 based on an emergy equation for crustal heat as the sum of emergy from Earth heat, solar input to Earth cycles, and tide (Odum, 2000a).

dTidal contribution to oceanic geopotential flux is 0.52E20 Jyr-1 (Miller, 1966). Solar transformity of 7.4E4sej J-1 is based on an emergy equation for oceanic geopotential as the sum of emergy from Earth heat, solar input to the ocean, and tide.

After Odum HT, Brown MT, and Brandt-Williams S (2000) Handbook of Emergy Evaluation, Folio 1: Introduction and Global Budget, 16pp. Gainesville, FL: Center for Environmental Policy, University of Florida. http://www.emergysystems.org/downloads/Folios/Folio_1.pdf (accessed December 2007).

Table 2 Emergy of products of the global energy system

Emergy3

Production

Emergy/unit

Product and units

(E24sejyr1)

(units yr"1)

(sej/unit)

Global latent heat (J)b

15.83

1.26 E24

12.6 sej J"1

Global wind circulation (J)c

15.83

6.45 E21

2.5 E3 sej J"1

Global precipitation on land (g)d

15.83

1.09 E20

1.5 E5 sej g"1

Global precipitation on land (J)e

15.83

5.19 E20

3.1 E4 sej J"1

Average river flow (g)f

15.83

3.96 E19

4.0 E5 sej g"1

Average river geopotential (J)g

15.83

3.4 E20

4.7 E4 sej J"1

Average river chem. energy (J)h

15.83

1.96 E20

8.1 E4 sej J"1

Average waves at the shore (J)i

15.83

3.1 E20

5.1 E4 sej J"1

Average ocean current (J)j

15.83

8.6 E17

1.8 E7 sej J"1

aMain empower of inputs to the geobiospheric system from Table 1 not including nonrenewable consumption (fossil fuel and mineral use).

bGlobal latent heat = latent heat of evapotranspiration 1020 mm yr1, (1020 mmyr"1)(1000gm"2mm"1)(0.58 kcalg"^(4186 J kcar^p^EMm2) = 1.26E24Jyr1.

cGlobal wind circulation, 0.4 W m"2 (0.4 J m"2 s"1)(3.15E7 syr"1)(5.12E14 m2/Earth) = 6.45E21 J yr1. dGlobal precipitation on land = 1.09E11 m3 yr"1 (1.09E14 m3)(1E6 kg m"3) = 1.09E20 g yr"1.

eChemical potential energy of rainwater relative to seawater salinity (1.09E20gyr"1)(4.94 J Gibbs free energy g"1) = 5.19E20 Jyr"1. 'Global runoff, 39.6E3km3yr"1 (39.6E12m3yr"1)(1E6gm"3) = 3.96E19gyr"1.

gAverage river geopotential work; average elevation of land = 875m. (39.6E12m3yr"1)(1000kgm"3)(9.8ms"2)(875 m) = 3.4E20 Jyr"1.

hChemical potential energy of river water relative to seawater salinity (3.96E19gyr"1)(4.94 J Gibbs free energyg"1) = 1.96E20 Jyr"1.

'Average wave energy reaching shores, (1.68E8 kcal m"1yr"1)(4.39E8m shore front)(4186 J kcal"1) = 3.1E20 Jyr"1.

'Average ocean current: 5 cms"1; 2 year turnover time (0.5)(1.37E21 kg water)(0.050 ms"1)(0.050ms"1)/(2yr) = 8.56E17 Jyr"1.

After Odum HT, Brown MT, and Brandt-Williams S (2000) Handbook of Emergy Evaluation, Folio 1: Introduction and Global Budget, 16pp.

Gainesville, FL: Center for Environmental Policy, University of Florida. http://www.emergysystems.org/downloads/Folios/Folio_1.pdf (accessed

December 2007).

Table 3 Annual emergy contributions to global processes including use of nonrenewable reserves in 2005

Inflow

UEVa

Empower

Inputs and units

(Jyr")

(sej/unit)

(E24 sej yr"1)

Renewable inputsb

15.8

Nonrenewable energies released by society

Oil, Jc

1.81E20

9.06E4

16.4

Natural gas, Jd

1.02E20

8.05E4

8.2

Coal (oil eq.), Je

1.23E20

9.06E4

8.3

Nuclear power (oil eq.), Jf

2.62E19

9.06E4

2.4

Wood, Jg

5.86E19

1.84E4

1.1

Soils, Jh

1.38E19

1.24E5

1.7

Phosphate, Ji

5.36E16

1.29E7

0.7

Limestone, Jj

7.82E16

2.72E6

0.2

Metal ores, gk

1.83E15

1.68E9

3.1

Total nonrenewable empower

42.1

Total global empower

57.9

aValues of solar emergy/unit from Odum (2001); Renewable inputs: total of solar, tidal, and deep heat empower inputs from Table 2.

bTotal oil production = 2.96E10 Barrels yr"1. Energy flux = (2.96E10 barrels)(6.1E9 J/barrel) = 1.81E20Jyr"1

cTotal natural gas production = 2.763E9 m3. Energy flux = (2.763E12 m3)(3.77E7 J m3) = 1.02E20 J yr"1.

dTotal coal consumption = 2.929E91 oil eq. yr"1. Energy flux = (2.929E91 yr"1)(4.186E10 J t"1 oil eq.) = 1.23E20 J yr"1.

eTotal nuclear power production = 627.2E6mt oil eq.yr"1). Energy flux = (627.2E6mt oil eq.yr"1)(4.186E10 J/t oil eq.) = 2.62E19Jyr"1.

'Annual net loss of forest area = 11.27E6hayr"1. Biomass = 40 kg m2; 30% moisture. Energy flux = (11.27E6 hayr"1)(1E4 m2ha"1) (40kgm2)

gTotal soil erosion = 6.1E10tyr"1. Assume soil loss 101 ha"1 yr"1 and 6.1E9 ha agricultural land = 6.1E16g"1 yr"1 (assume 1.0% organic matter), 5.4 kcal g"1. Energy flux = (6.1E16 g)(0.01)(5.4 kcal g"1)(4186 J kcal"1) = 1.38E19 J yr"1.

hTotal global phosphate production = 154E6 mtyr"1. Gibbs free energy of phosphate rock = 3.48E2 J g"1. Energy flux = (154E12g) (3.48E2 J g"1) = 5.36E16 J yr"1.

'Total limestone production = 128E6mtyr"1. Gibbs free energy limestone rock = 611 J g"1. Energy flux = (128E12g)(6.11E2Jg"1) = 7.82E16Jyr"1. kTotal global production of metals (1994): Al, Cu, Pb, Fe, Zn: 1.825E9mtyr"1 = 1.825E15gyr"1.

Table 4 UEVs for primary nonrenewable energy sources and some common products

Table 5 Summary of UEVs in terrestrial ecosystems

Table 4 UEVs for primary nonrenewable energy sources and some common products

Transformity

Specific emergy

Item

(sejJ-1)

(sejg-1)

Primary nonrenewable

energy sources

Plantation pine (in situ)

1.1E4

9.4E7

Peat

3.2E4

6.7E8

Lignite

6.2E4

Coal

6.7E4

Rainforest wood

6.9E4

4.1E8

Natural gas

8.1E4

Crude oil

9.1E4

Liquid motor fuel

1.1E5

Electricity

3.4E5

Common products

Corn stalks

6.6E4

Rice, high energy

7.4E4

1.4E9

Cotton

1.4E5

Sugar (sugar cane)

1.5E5

Corn

1.6E5

2.4E9

Ammonia fertilizer

3.1E6

Silk

6.7E6

Wool

7.4E6

Phosphate fertilizer

1.7E7

Steel2

8.7E7

After Odum HT (1996) Environmental Accounting: Emergy and Environmental Decision Making. New York: Wiley.

Ecosystem

After Odum HT (1996) Environmental Accounting: Emergy and Environmental Decision Making. New York: Wiley.

UEV is based on only one evaluation, for instance, plantation pine. In other cases, several evaluations have been done of the same primary energy but from different sources and presumably different technology, so UEV is an average. Obviously each primary energy source has a range of values depending on source and technology. By using data from typical production facilities (and actually operating facilities), the UEVs represent average conditions and can be used for evaluations when actual unit values are not known. If it is known that conditions where an evaluation is being conducted are quite different than the averages suggested here, then detailed evaluations of sources should be conducted.

Table 4 also lists the UEVs for some common products in the order of their transformity. Only a few products are given here, while many more evaluations leading to UEVs have been conducted and are presented in a set of Emergy Folios, published by the Center for Environmental Policy at the University of Florida (http://cep.ees.ufl.edu/).

Gross primary production

Subtropical mixed hardwood forest, Florida

Subtropical forest, Florida

Tropical dry savanna, Venezuela

Salt marsh, Florida

Subtropical depressional forested wetland, Florida Subtropical shrub-scrub wetland, Florida Subtropical herbaceous wetland, Florida Floodplain forest, Florida

Net primary production

Subtropical mixed hardwood forest, Florida

Subtropical forest, Florida

Temperate forest, North Carolina (Quercus spp.)

Tropical dry savanna, Venezuela

Subtropical shrub-scrub wetland, Florida

Subtropical depressional forested wetland, Florida

Subtropical herbaceous wetland, Florida

Biomass

Subtropical mixed hardwood forest, Florida

Salt marsh, Florida

Tropical dry savanna, Venezuela

Subtropical forest, Florida

Tropical mangrove, Ecuador

Subtropical shrub-scrub wetland, Florida

Subtropical depressional forested wetland, Florida

Subtropical herbaceous wetland, Florida

Wood

Boreal silviculture, Sweden (Picea aibes, Pinus silvestris)

Subtropical silviculture, Florida (Pinus elliotti) Subtropical plantation, Florida (Eucalyptus and

Malaleuca spp.) Temperate forest, North Carolina (Quercus spp)

Peat

Salt marsh, Florida

Subtropical depressional forested wetland Subtropical shrub-scrub wetland Subtropical wetland

1.03E + 03 1.13E + 03 3.15E + 03 3.56E + 03 7.04E + 03 7.14E + 03 7.24E + 03 9.16E + 03

2.59E + 03 2.84E + 03 7.88E + 03 1.67E + 04 4.05E + 04 5.29E + 04 6.19E + 04

9.23E + 03 1.17E + 04 1.77E + 04 1.79E + 04 2.47E + 04 6.91E + 04 7.32E + 04 7.34E + 04

number of global ecosystems. These data, published in research reports, dissertations, and theses, were complied in an Emergy Folio published by the Center for Environmental Policy at the University of Florida (http://cep.ees.ufl.edu/). Generally UEVs for ecosystem components increase as the products increase in energy density, with highest values associated with peat accumulations in subtropical wetlands.

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