How do you use energy? • Your life –
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How do you use energy? • Your life – – How do you use energy? • Rank order the energy use by highest to lowest amount. • Rank order them in GHG emissions – How do you use electricity? READ: U.S. DOE Energy Perspectives http://www.eia.gov/emeu/aer/pdf/perspectives_2009.pdf http://www.eia.doe.gov/energyexplained/index.cfm?page=us_energy_home How we use Electricity Other Equipment 3% Laundry Appliances 7% Household Electricity Consumption Air-Conditioning 17% Home Electronics 8% Lighting 10% Space Heating 11% HVAC Appliances 5% Water Heating 10% Kitchen Appliances 29% Per average household Electricity is 42% of home energy use Energy Use (quadrllion Btus) U.S. Total Residential Energy Use 25 20 Grand Total Direct Use Direct Electricity Use 15 10 Electrical system energy losses 5 0 1970 1980 1990 2000 2010 Source: Energy Information Administration/Monthly Energy Review December 2007; www.eia.doe.gov Definitions Energy: A measure of the ability to do work. Power: The rate at which energy is used. Key Point ! POWER ≠ ENERGY Work = Force x Distance (Joules) Work = Energy Power = Energy Time So Energy (J/s = Watts) = Power x time (kWh) What is ENERGY efficiency? Other outputs (non-useful) Input Output Process πΆπππππ π¬πππππ π¬πππππππππ = < 1.0 π°ππππ π¬πππππ Light Bulb Energy Use Consider a 100 watt light-bulb: – 100 watts for one hour is 100 watt-hours or 0.1 kWh Since 1 kWh costs approximately 17 cents, your 100 watt bulb costs about 1.7 cents to operate for an hour $31/y if on 5 h/d; 365 d/y How can you decrease your cost? Heat (thermal energy) (not useful energy) Light Electricity (electric) (radiant) Useable energy • Turn the light OFF Conservation • Replace bulb with CFL Efficiency Focus on Efficiency Other energy outputs (non-useful) (e.g., heat) Useful Energy Out Energy in Process • Less than 1/4 energy used in stove reaches food • Waste heat from US power plants could power the Japanese economy • 15% of energy in gasoline reaches wheels of a car • 2.7 mpg increase in light vehicle fleet would displace Persian Gulf imports (Amory Lovins) Cost of Carbon Savings (Euros/tonne CO2) 50 Switch – coal to gas power plants Carbon capture – retrofit coal power plants Solar Forestation Wind Carbon capture – new coal power plants Cellulosic ethanol Sugar cane ethanol Fuel efficient vehicles Efficient water heating Efficient lighting Insulation improvements Fuel efficient commercial vehicles Focus on Increased efficiency 0 -50 -100 -150 (The Economist June 2, 2007) What Makes our Energy Use “Efficient”? • Most of energy input converted into most useable form of output. – Our use of the process is “efficient” – The technological product itself is efficient – The production of the energy we use is efficient What makes a system NOT efficient • Heat related – Seals not shut tightly – Poorly insulated • Power / electronics – Not turned off when done – Conversion process creates un-useable forms of energy • Heat • Vibration • Noise – Phantom loads To fix inefficiencies ο • Change the user habits • Change to better technology Efficiency of electricity generation • Electricity is a Secondary Energy Source • Coal ο electricity ο home = very inefficient Energy Flows “Losses” Extraction processing Fossil fuel Fossil fuel combustion Thermal energy “Losses” engine, turbine “Losses” Conversion to electricity Mechanical electricity energy ?? MJ 100 MJ Energy Efficiency of power plants: Did You Know? A pound of coal supplies enough electricity to power ten 100-watt light bulbs for about an hour. Coal NG Residual Oil Biomass 30-46% 33-53% 35% 32-40% Estimating CO2 emissions 2750 kg CO2 990 kg CO2/MWh Coal 75% Carbon 30,000 kJ/kg 1000 kg CO2 ?? kg/MWh Electricity ?? MWh Coal-fired Power Plant 33.3% efficient 2.78 MWh IPCC Estimation Approaches • Tier 1: – All C atoms in fuel eventually ends up as CO2 – CH4 and N2O from IPCC default emission factors that vary by technology and fuel • Tier 2: Region-specific Emission Factors – Primary fuel X emission X equivalency consumed factor factor (GWP) = mass CO2 eq./energy value – Emission factors vary • by fuel • technology used to consume fuel • therefore, by country, region – Emission factors from IPCC and other sources http://www.ipcc-nggip.iges.or.jp/public/2006gl/pdf/2_Volume2/V2_1_Ch1_Introduction.pdf CO2 emissions - various fuels Coal (anthracite) Coal (lignite) Coal (subbituminous) Coal (bituminous) Wood and wood waste Fuel oil Kerosene Automobile gasoline Aviation gasoline Propane Liquefied petroleum gas Natural Gas 0 20 40 60 80 100 120 CO2 emitted (g/106 J fuel combusted) What are the consequences of fuel choice on GHG emissions? Electricity from Coal Hydroelectricity ? Nuclear Electricity Example – CO2 from Electricity • Questions: – – – – How much GHGs do you generate with electricity use? Does it matter where you live? Explain Why or Why not What can you conclude about New York State? • Procedure: – Explore fuels used and resulting CO2 emissions – http://epa.gov/powerprofiler Your home town (or school) East Hampton NY 11937 Boston MA 02129 Seattle WA 98101 Los Angeles CA 90001 Columbus OH 43201 Chicago IL Kansas City MO Atlanta GA Denver CO Honolulu HI 60601 64101 30301 80012 96801 Regional differences do matter U.S. Total http://cfpub.epa.gov/egridweb/reports.cfm - summary tables - 2005 What is a lifecycle perspective? • Typical approach – Reduce environmental impacts in one component – Create new and different environmental impacts in another component • Better approach – Consider the whole systems rather than small and isolated parts of a system Electric car Electricity Use Water Use Nuclear fuel mining and processing Nuclear Electricity Electric Power Transmission Electricity from Coal Water Use Air Emissions Hydroelectricity Water Use Air Emission s Fuel Use Transportation Fuel Use Coal from mining Petroleum Fuel Water Use Air Emission s Spills to Water/Soil LC GHGs vary by electricity fuel source Coal Lifecycle Emission Factors (g/million Btu) Coal Mining: NonCoal Mining Combustion and Cleaning Emissions CH4 1.09E+00 N2O CO2 Coal Transportation to Power IGCC Plants Turbine total for coal % at combustion 8.74E-01 5.10E+00 1.24E+02 4.1% 1.36E-02 1.82E-02 5.10E+00 5.13E+00 99.4% 8.78E+02 7.56E+02 1.08E+05 1.10E+05 98.5% 1.17E+02 Emission Factors for NY Energy Source Natural Gas kg CO2 kg eCO2 52.76 52.92 mmBtu 14.43 155.46 short ton 14.43 155.46 short ton Gasoline Fleet 8.71 8.93 gallon Diesel Fleet 9.99 10.08 gallon E85 Fleet 0.95 1.18 gallon B20 Fleet 7.85 7.94 gallon B100 9.46 9.55 gallon Electricity (NY) 0.33 0.33 kWh Air travel 0.77 0.78 mile Wood Chips Wood Pellets per Clean Air Cool Planet - http://www.cleanair-coolplanet.org/toolkit/inv-calculator.php Energy/GHG - Key Points • Energy demand and GHG emissions continue to grow • US relies a great deal for generating electricity on coal - (~50%) on the worst fossil fuel in terms of CO2 emissions • Efficiency of our energy systems low • What do we do to “fix” this? Defining Priorities • What sector(s) should we focus on? • Why? Further reading • EPA – Energy and You – http://www.epa.gov/cleanenergy/energy-and-you/index.html • DOE – Energy and the Environment – http://www.eia.doe.gov/energyexplained/index.cfm?page=environment_ where_ghg_come_from • World Resources Institute – Climate Analysis Indicator Tool – http://cait.wri.org/
