Energy and Society Development stages • Pre-agricultural era (human power) • Agricultural era (animal power) • Mechanical power era • Fossil fuels • Electricity Foraging society • Energy needs covered by human body • Sustained power 50-90 W, short-run power 100 W, maximum power 1000 W. • Transformation efficiency: • Chemical energy food => muscles up to 99 % • Chemical energy => kinetic energy around 20-25 % • Energy return on investment (EROI) up to 40, usually around 3, often around 1. • Very low population density (0,1 person/sq. km) • Exosomatic sources of power: fire, body extensions (bows) Agricultural society • Very slow pace of transition (never finished) • Greater population density (20-30 persons/sq. km) • First exosomatic sources of power: • Oxes (200-500 W) • Charcoal (29 MJ/kg, no smoke) • Metallurgy: low efficiency, high energy intensity (until 1750) • Mechanical propulsion (windmills) Energetický determinismus 5 Progress in the Middle Ages • Organic prime movers still dominant • Increased efficiency in energy transformation (treadwheels, horseshoes, fodder, breeding) • Non-organic prime movers • Watermills (England, 11th century) • Wind power: sails (+ compass, heavy cannons, rear stear = colonization) • Fuel scarcity (England at 1710s: 12 000 tons of wood/year) Energetický determinismus Středověké a raně-moderní pokroky dominance organických zdrojů energie postupné pokroky v efektivitě konverze (šlapací kola, kladky, podkovy, chomouty, krmiva, pěstění zvířat) – až 50% nárůst oproti antice ne-organické zdroje hnací síly: vodní mlýny v JV Anglii (4 kW) 11. století větrná energie: zdokonalení plachet (+kompas, těžká děla a kormidlo na zádi = zámořské objevy) 15. století: první tavící pece v údolí Rýna nedostatek paliva (poptávka průměrné pece v Anglii začátku 18. století je 12 000 tun dřeva ročně) 7 Towards modernity: steam engine • Europe: 1800-1950: Five distinct prime movers: humans, animals, watermills/turbines, windmills, steam engines • Fossil fuels: peat replacing wood in Holand (17th Century) • Steam engine (Newcomen, Watt) • 20 kW • Efficiency 5% • Inland transport revolution • „Industrial revolution“ powered by watermills and steam (positive feedback) • 1870: mechanical power outweighs organic power in the U. S. • 1900: North Sea windmills: 100 MW of installed capacity Evoluční přístup 9 Towards modernity: electricity • Production, transport, and use of electricity introduced between 1880-1900 • Basics laid by T. A. Edison in early 1880s • G. Westinghouse and N. Tesla: alternating current • Ch. Parsons: steam turbine • W. Stanley: transformer • N. Tesla: electric motor • 20th century: evolution of power industry • USA 1930s: 80% of all mechanical power • Profound change in work and personal life Towards modernity: internal combustion engine • 1890s: • Spark ignition engine (G. Daimler), carburator (W. Maybach), electrical ignition (K. Benz). • Compression ignition engine (R. Diesel) • Three waves of automobile dissemination • Aviation • 1904: the Wright brothers • 1961: Yuri Gagarin • 1969: Neil Armstrong, Boeing 747 • Fossil fuels-based transportation drives demand for oil, later on utilized in a variety of industries Energetický determinismus 13 Energy-intensive society • Mechanization of agriculture and industry • Geometrical growth of available power: Foraging societies 100 W (human) Early antiquity 300 W (ox) Ancient Rome 2 kW (watermill) The Middle Ages 5 kW (watermill) 17th century 8 kW (watermill 18th century 100 kW (Watt‘s steam engine) Early 20th century 10 MW (water turbine) Early 21st century 1,5 GW (gas turbine) • Last 10,000 years: • Maximum power of the prime movers has increased 15,000,000x • 99% of this change occurred in 20th century • Still a modest number compared to yield of weapons used Energy-intensive society • Increased quality of life • Great differences among societies/nations • 10% consumes 40% of all primary energy • 50% consumes 10% of all primary energy • Anthropocene Conclusions • Development stages reflect the power, efficiency, and flexibility of employed prime movers • Harnessing more energy leads to greater complexity of society