geothermal, solar, wind 1% hydropower 2% energy · 2016-03-15 · energy unit 5 renewable resources...
Transcript of geothermal, solar, wind 1% hydropower 2% energy · 2016-03-15 · energy unit 5 renewable resources...
energyunit 5
renewable resources• renewable
• solar• wind• hydroelectric• wood• geothermal
• non-renewable• fossil fuels
• oil, coal, natural gas• nuclear? (uranium)
nonrenewable87%
renewable13%
hydropower2%
geothermal, solar, wind1%
nuclear power6%
natural gas21%
coal26%
oil34%
biomass10%
Worldwide commercial energy mix, 2010
net energy• net energy yield
• each energy production process involves energy investment
• gross energy production - investment = net energy yield• more steps involved in
finding and using energy source, lower net energy yield
source net energy yield
reducing waste high
gasoline medium
natural gas medium
ethanol (sugarcane) medium
diesel medium
gasoline from heavy shale oil low
gasoline from tar sands oil low
ethanol (corn) low
biodiesel low
hydrogen negative
transportation energy sources
direct solar• solar cooking
• solar cookers and ovens• passive solar heating
• absorbs and stores heat during the day
• active solar heating• radiators
• solar thermal system• mirrors collect and focus sunlight • low net energy yield• Ivanpah (5 mi2)
• solar cells
hydro• hydroelectric power
• dams and reservoirs• tidal?
biomass• solid biomass
• wood, crop residues, animal waste• wood is most used renewable energy source
• biofuel• biodiesel• ethanol
geothermal• geothermal energy
• geothermal heat pump system• hydrothermal reservoirs
wind power• wind farms
• high net yield• turbines generate electricity• power lines carry electricity• clusters of windmills capture
favorable winds
wind power• trends in wind power
• lots of growth• 35% average 2007-2011
• calls for smart grid• could distribute energy
efficiently to eliminate regional effects of wind energy production
nuclear?• not renewable• low net energy yield
• high cost, efficiency loss in mining / processing
• inefficient power plants• waste?• safety issues?
portable energy• transportation
• hybrid cars• PHEV• HEV
• hydrogen• solar• biodiesel
hydrogen• hydrogen gas, H2
• can be produced by running electrical current through water -- electrolysis
• can be removed from methane (CH4)• negative net energy yield• no emissions other than water
what about oil• crude oil production
• peak production• proven oil reserves• heavy oil
• shale oil• tar sands
• low net energy yield• harmful environmental
impacts
improving efficiency• energy efficiency
• cheapest, fastest, safest way to reduce consumption• industry
• cogeneration• can double the efficiency of an power plant
• recycling• replacing lightbulbs
• transportation• increase efficiency standards• hybrids• less reliance on cars
• houses, buildings
discussion questions• what energy sources do you think people will be using 50
years into the future?• nuclear?
• what do you do that wastes energy? • are you willing to change?
• should we stop developing energy resources with low or negative net energy yield?• tar sands• hydrogen?
• what is the most promising / best energy source, all things considered?