Energy in Context

Overview Magnitude of Energy Use -Implications to human living -Implications to global climate change Technological Cycles –Impact of human practices on energy use

Magnitude of Energy Use Energy Required to raise 100 kg a distance of 1 m. ~1000 Joules Energy required for 60 Watt light bulb operating 1 hours ~216,000 Joules Energy required to heat 5 kg pan of water to boiling temperature ~1,670,000 Joules Energy required to process 1 kg wood products ~2,000,000 Joules Energy required to process 1 kg of plastic products ~100,000,000 Energy required to mine/smelt 1 kg aluminum ~220,000,000 Joules Energy required to drive an SUV 25 miles ~200,000,000 Joules

Implications for how we live?

Connection to ‘Global Climate Change’ (gCO 2 per 3,600,000 Joules) Energy SourceCoalOilGasHydroNuclearSolar PV Current technology Next generation technology

Energy Efficiency of Industrialized Economy Est. 1-3% Why so low?

Product Life Cycle Consider life cycle energy impact of a 1 kg of aluminum being used in an aluminum wheel of a Ford Excursion over a 150,000 mile life.

Case A – No Recycling

Life Cycle Stage Total Energy Input from Fuel (typical) Energy efficiency (typical), %, Minumum energy required if 100% efficient Mining10 MJ/kg MJ/kg Materials Processing 220 MJ/kg60132 MJ/kg Manufacturing - Casting 20 MJ/kg6012 MJ/kg Use[1][1]375 MJ/kg-al MJ/kg Total625 MJ/kg [1][1] Ford Excursion = 3000 kg, 15 mpg, 150,000 miles/life…Useful energy from I.C. engine overcomes rolling resistance, inertia, drag. 75% of this is dependent upon weight. Therefore the mass consumed in the burning of gasoline over life due to the 1 kg mass on the vehicle is: (150,000 miles/life)/(15 miles/gallon) x (3 kg-fuel/gallon) / 3000 kg-al x 0.75 = 7.5 kg – fuel/kg-al Energy consumed = 7.5 kg-fuel/kg-al x ( 50 MJ/kg-fuel) = 375 MJ/kg-al

Nylon $2.50/kg MaterialVirgin MJ/kg Recycle d MJ/kg Cost[1][1] Aluminum220 20$1.50/kg Polyethylene98 56$0.80/kg PVC65 29$1.20/kg Steel40 18$0.45/kg Glass30 13$0.20/kg Copper200 10$5.00/kg [1][1] Source: American Metals, amm.com

Case B – Recycling r% of the aluminum

Same energy use as in Case A except that the mining energy and material processing energy are reduced by: r(E mining + E materials ) where r is the fraction of recycled aluminum going into the making of a new wheel

Life Cycle Stage Total Energy Input from Fuel (typical) MJ/kg-al Energy efficiency (typical), %, Minumum energy required if 100% efficient MJ/kg-al Mining(1-r) 1030(1-r) 3.33 Materials Processing (1-r) 22060(1-r) 132 Manufacturing Use[1][1] Total395+(1-r)230… (1-r) [1][1] Ford Excursion = 3000 kg, 15 mpg, 150,000 miles/life…Useful exergy from I.C. engine overcomes rolling resistance, inertia, drag. 75% of this is dependent upon weight. Therefore the mass consumed in the burning of gasoline over life due to the 1 kg mass on the vehicle is: (150,000 miles/life)/(15 miles/gallon) x (3 kg/gallon) x 0.75 / 3000 = 7.5 kg – fuel Exergy consumed = 7.5 kg-fuel x ( 50 MJ/kg-fuel) = 375 MJ/kg-al

Comparison

Cost Comparision If 100% recycle and given a cost of $0.10 / (3.6 MJ), a 230 MJ reduction in energy yields a $6.30 savings per kg Note: This is 4 times more expensive than it would seem because aluminum companies have been given cheap access to hydroelectric energy!!!!!

Energy Generation Efficiency ProcessEfficiency Coal  Electricity  transmission 20% Natural gas  electricity  transmission 25% Fuel Cell40% (70-80%) if heat used Solar PV20% typical Wind30%