Achieving a sustainable energy balance for the U.S. current energy mix - 80% fossil fuel increasing renewables (wind, solar, tidal, geothermal, etc) increasing nuclear carbon sequestration (?) electricity as primary energy carrier biomass/biofuels (?) unconventional hydrocarbons (?) Regulation and ‘reasonable cost’ strategies carbon emissions tax (‘cap and trade”) tax incentives ‘hidden costs’ (e.g. health, environment) in current energy systems

Sankey diagram – ‘lost energy’ - gains from greater efficiency in energy conversions (Evans figure 10.1) co-generation capture waste heat (e.g. coal-fired plants) minimize conversion steps Move to ‘electricity economy’ – electricity as primary energy carrier increase generation capacity battery technology limitations in transport renewable/nuclear mix (Evans scenario 1 – figure 10.3) coal with carbon dioxide sequestration (Evans scenario 2 – figure 10.4)

Costs of renewable sources of electricity - capital and operating Wind – 8 cents per KWH Photovoltaics – 30 cents per KWH Biomass – 7 cents per KWH Landfill gas - 7 cents per KWH Geothermal – 8 cents per KWH Small hydro – 8 cents per KWH Tidal - 12 cents per KWH Coal – 4.5 cents per KWH Nuclear – 8 cents per KWH

Natural gas as intermediate solution (Boone Pickens scenario) lower carbon emissions per unit of energy compared to coal reserves more widespread than petroleum makes use of existing technology CNG for transportation LNG for long-distance transport Social consequences in any scenario Modification of behavior (e.g. public transportation) Cultural adaptation (e.g. to windfarms, smaller houses) Economic impact – higher energy costs

What is the intermediate term outlook according to the EIA? (OECD – Organization for Economic Co-operation and Development 40 countries)