Energy Units & Consumption ESM 102

Sources of Energy

Natural Gas 0 Sold in units of THERMS cubic feet 0 Hydrocarbon mixture (mostly methane) 0 Uses: generating electricity, heating houses, providing heat & power to industry and vehicles 0 Found deep in underground rock formations & above crude oil reservoirs 0 Cheaper than oil, easy to transport, burns hotter & cleaner than other fossil fuels 0 Leaks of natural gas into atmosphere

Electricity 0 Sold in units of kilowatt hours (kWh) watt hours 0 Sources of electricity: 0 Fossil fuel combustion 0 Wind power 0 Hydropower 0 Can’t be easily stored…must generate as much as needed

Kilowatt Hours

Heating Oil 0 Sold in units of gallons 0 Low viscosity, flammable liquid petroleum similar to diesel fuel 0 Stored in above or underground storage tanks 0 Fuel for furnaces or boilers

Gasoline 0 Sold in units of gallons 0 Petroleum derived liquid used for fuel in internal combustion engines 0 In US and many other countries, gasoline blended with up to 10% ethanol 0 US accounts for 44% of world wide usage

Wood 0 Sold in units of cords 0 = 4’ x 4’ x 8’ stack of wood 0 = 250 copies of Sunday NYT 0 1 forested acre produces cords 0 Amount of energy depends on type of wood 0 Density 0 Water content

Energy in terms of BTUs 0 1 Calorie = BTUs 0 Heating Oil: 1 gallon = 138,690 BTUs 0 Gasoline: 1 gallon = 124,238 BTUs 0 Natural Gas: 1 therm = 100,000 BTUs 0 Electricity: 1kWh = 3412 BTUs 0 Coal: 1 short ton = 19,858,000 BTUs