EMERGY & ENERGY SYSTEMSEMERGY & ENERGY SYSTEMS

Session 9 Short Course for ECO Interns,

EPA and Partners

Scale and Boundary DefinitionScale and Boundary Definition

• Scale and net benefits

• Timescales

Session Goals

Scale and Net BenefitsScale and Net Benefits

• Product

Scale and Net BenefitsScale and Net Benefits• Product

Data Solar EMERGYNote Description (per ha-1 yr-1) (E13 sej/yr)

Renewables1 Sun 6.35E+13 J 62 Rain 4.07E+10 J 1233 Et 6.02E+10 J 156

Non-renewables4 Net Topsoil Loss 6.33E+07 J <1

Purchased5 Fuel 7.37E+10 J 8176 Electricity 0.00E+00 J 07 Potash 1.39E+05 g K 268 Lime 3.29E+06 g 5539 Pesticides 1.59E+05 g 401

10 Phosphate 4.60E+04 g P 17011 Nitrogen 4.75E+04 g N 19212 Labor 1.20E+09 J 1613 Services 4.38E+03 $ 119914 Total EMERGY 3530

Table 1.20: Emergy Evaluation of Tomato, per ha per year

Scale and Net BenefitsScale and Net Benefits

• State/

Regional

Scale and Net BenefitsScale and Net Benefits

• Sub-process

Scale and Net BenefitsScale and Net Benefits

• Adding larger scale items into evaluation

Data Solar EMERGYNote Description (per ha-1 yr-1) (E13 sej/yr)

Renewables1 Sun 6.35E+13 J 62 Rain 4.07E+10 J 1233 Et 6.02E+10 J 156

Non-renewables4 Net Topsoil Loss 6.33E+07 J <15 Lime 3.29E+06 g 5536 Phosphate 4.60E+04 g P 1707 Gypsum treatment 2.95E+12 J 9418 H2SO4 treatment 2.51E+10 g H2O 45

Purchased9 Fuel 7.37E+10 J 81710 Electricity 0.00E+00 J 011 Potash 1.39E+05 g K 2612 Pesticides 1.59E+05 g 40113 Nitrogen 4.75E+04 g N 19214 Labor 1.20E+09 J 1615 Services 4.38E+03 $ 1199

Total EMERGY 4516

Scale and Net BenefitsScale and Net Benefits

• Net benefits– Multi-scalar

• Person• Economy• US• Planet Earth

Clinton tax credit

for high MPG cars, 1998

sej/yr

1. CO2 avoided 6.15E14

2. Gas saved3.40E15

3. $ not in circulation4.40E14

4. $ from tax credit3.60E15Benefit/Deficit

Person: 3 + 4 = 4.04E15Economy: 4 – 3 = 3.16E15

National Security: 1 + 2 – 4 = 4.10E14Global: 1 + 2 = 4.01E15

1

2

3

4No Credit

WithCredit

Scale and Net BenefitsScale and Net Benefits

• Geographic versus political– Watershed versus state or county– Environment difficult to manage from political – Data difficult to obtain for watersheds

Time ScalesTime Scales

• Short term versus long, human versus geologic– Economy evaluated annually– Renewables evaluated using long term averages– Information turnover: 2-3 months?– Cultural information: 15 – 1000 years?– Watersheds: same as dominant ecosystem?– Watersheds: same as average rain cycle?– Watersheds: same as geologic cycle?

Time ScalesTime Scales

• Cumulative versus single event– Annual flows are “snapshots”– Average flows need to encompass appropriate time period– Cumulative evaluations best used for impacts– Cumulative may be better represented by simulation