Solar Energy and Personal Behaviors

Transcription

1 Solar Energy and Personal Behaviors Emissions reductions need to be rapid and large - 80% reduction by 2050 to avoid worst scenarios Urgent need for alternate energy sources solar wind 1

2 Algae as a source of green liquid fuel Diatoms are single-celled algae that make silica shells Some produce 60% lipid by weight Lipids can be converted to biodiesel or other petroleum substitute Estimated oil production: 5,000-20,000 gallons/acre/year At least 10 times yield of next best biofuel crop (palm oil) >200 times higher yield than corn ethanol 2

3 DOE: In open raceway ponds, enough biodiesel to replace ALL petroleum transportation fuels could be grown in ~10 million acres (~12.5% of the Sonora desert) Can be produced domestically on otherwise economically undesirable land - cost estimated by U.S. National Renewable Energy Laboratory to be $1.65 to $2.75/gallon 3

4 Wind power could supply 16 times current U.S. electricity demand using only onshore turbines - Michigan can supply 12 times our use Solar is the most plentiful energy source More energy reaches Earth from the sun in 1 hour than humans on the entire planet use in 1 year! 4

5 Two main ways to capture solar energy 1. Photovoltaic (PV) panels - generates electricity directly 2. Concentrating solar power (CSP) - generates heat, then steam, then electricity Three main methods for Concentrating Solar Power 1. Central tower: mirrors concentrate the sun's energy on a heat exchanger located on a central tower 5

6 2. Parabolic trough: long, curved mirrors concentrate the sun's energy on a pipe that runs down the center of the trough - this heats the oil flowing through the pipe, which boils water in a conventional steam generator to produce electricity Mojave desert, CA 3. Parabolic dish: parabolic mirrors concentrate the sun's energy on a Stirling engine - heat causes expandable fluid to drive a piston or turbine to produce electricity New Mexico - can be used on individual level or in large arrays 6

7 We have very good solar sites in the U.S. But August is much better than January 7

8 A solar array 100 x 100 miles could provide all of US electricity needs today Could solar energy be used to power Europe? 8

9 Could solar energy be used to power Europe? A small portion of the Sahara desert could supply all of Europe s electricity (and the world s) 9

10 Excess energy captured during the day could be stored as heat and used to produce electricity at night - can help stabilize the grid CSP could also help greenify the desert - excess energy could be used to run desalinization plants Northern Egypt coast 10

11 Greenhouses could even be located under parabolic trough arrays Globally, can wind and solar supply enough energy? 12,000 Energy (EJ/yr) 10,000 8,000 6,000 4,000 2,000 Today Global Demand Wind Potential Solar Potential 11

12 Who are the global leaders in solar energy? Company Suntech LDK Canadian Solar Trina Yingli Hanwha Solarone SolarWorld Jinko Sunneeg Sunpower Capacity (MW) 2,400 2,500 2,000 1,900 1,700 1,500 1,400 1,100 1,000 1,000 Country China China China China China China Germany China China USA Sooo we re not doing it now because the cost is much higher than electricity from coal, right? 12

13 Sooo we re not doing it now because the cost is much higher than electricity from coal, right? Coal electricity doesn t include many external costs - e.g. the cost of its CO 2 emissions 13

14 - e.g. the human health effects of pollutants When all true costs are included, coal is more expensive than almost all green options 14

15 The real problem involves not building better technologies but convincing regulators and ratepayers that it is in society s best interest to price electricity fairly and accurately. (Sovacool 2008) 15

16 Humanity already possesses the fundamental scientific, technical, and industrial know-how to solve the carbon and climate problem for the next half-century. (Pacala and Socolow, Science 2004) 7 emission reduction wedges needed to maintain emissions at 2004 levels through would keep CO 2 level <500 ppm by 2054 What can I do in the meantime to minimize adverse impacts of climate change? Household behaviors could provide one wedge Household energy use accounts for ~38% of overall U.S. CO 2 emissions ~ 8% of global emissions more than any country s emissions (except China s) 16

17 What can I do over the next 10 years to minimize adverse impacts of climate change? Most important behavioral changes: 1. Replace 20.8-mpg vehicle with 30.7-mpg vehicle Next time, buy a more fuel-efficient car 20 mpg 30 mpg 34 mpg 50 mpg Increasing by 10 mpg saves $585 and 1.6 tons of CO 2 per year 17

18 What can I do over the next 10 years to minimize adverse impacts of climate change? 2. Weatherize your house: weather-strip, adequately insulate attic, and replace single-pane windows with triple-pane windows - with 90% compliance, would reduce CO 2 emissions by 21 million tons (3.4% of overall household emissions) 18

19 What can I do over the next 10 years to minimize adverse impacts of climate change? 3. Next time, buy energy star appliances - with 80% compliance, would reduce CO 2 emissions by 12 million tons (1.9% of overall household emissions) 19

20 What can I do over the next 10 years to minimize adverse impacts of climate change? 4. HVAC equipment: when necessary, replace older furnace and central AC unit with Energy Star model - with 80% compliance, would reduce CO 2 emissions by 11 million tons (1.7% of overall household emissions) 20

21 5. Change to compact fluorescent light bulbs One per household would have the same effect as taking 6 million cars off the road 6. Turn the thermostat down (winter) or up (summer) Can save 7 tons of CO 2 per year for a family of four 21

22 7. Buy green electricity One GreenBlock supports 150 KWh of electricity from wind and landfill methane - same as driving 3,300 fewer miles - costs $1.50/month Unfortunately, energy conservation is not a solution - really just delays the inevitable 50 mpg 22

23 Emissions reductions need to be rapid and large - 80% reduction by 2050 to avoid worst scenarios Urgent need for alternate energy sources solar wind Who has the largest impact on Earth s future? 8. Contact your representatives! 23

24 9. Educate others 10. Vote 24

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