1. Options

2. Energy Future: Options(An SE’s Sample Of Topics) • Options for sources • “Reduced Carbon” fossil fuel • Renewables • Nuclear • Options for energy transport systems • Hydrogen • Options for efficiencies • Distributed generation • Spinning reserve • Options for policies

3. Energy Future: Options • Topics: • The importance of Natural Gas • A solar future • Nuclear?

4. Carbon Intensity of Energy Mix M. I. Hoffert et. al., Nature, 1998, 395, 881 Source: Nathan Lewis

5. LNG • Worldwide proven reserves of Natural Gas: 5500 T ft3 • 1999 – 84 T ft3 total, worldwide production • U.S. production of liquefied natural gas (LNG) has plateaued. • New U.S. electric power plants are largely natural gas • Prediction: by 2020, 25% of the world’s energy will be natural gas • Consumption: • 1997 LNG – 4 T ft3 • 1999 LNG – 5.4 T ft3 shipped • 2010 LNG – U.S. will go from .5 T ft3 to 2.2 T ft3 Source: Arabicnews.com, 12/19/2003

6. LNG http://www.kryopak.com/LNGships.html LNG requires a heavy infrastructure for cooling and transportation. This is currently capacity limited. http://www.energy.ca.gov/lng/

7. Coal Gasification And Sequestering • Great Plains Coal Gasification Plant (North Dakota) • From coal to the equivalent of natural gas • Sequester carbon dioxide into oil fields to assist in pumping • Oil field operator pays for Carbon Dioxide http://www.dakotagas.com/

8. Renewable Energy Potential Recall that the world needs 20 TW of carbon-free energy by 2050. Source: Turkenburg, Utrecht University

9. Solar Energy Potential • Facts: • Theoretical: 1.2x105 TW solar energy potential (1.76 x105 TW striking Earth; 0.30 Global mean albedo) • Practical: ≈ 600 TW solar energy potential • 50 TW - 1500 TW depending on land fraction etc.; WEA 2000 • Onshore electricity generation potential of ≈ 60 TW (10% conversion efficiency): • Photosynthesis: 90 TW Source: Nathan Lewis

10. Solar Thermal Energy Potential • Roughly equal global energy use in each major sector: • transportation • residential • transformation • industrial • World market: 1.6 TW space heating; 0.3 TW hot water; 1.3 TW process heat (solar crop drying: ≈ 0.05 TW) • Temporal mismatch between source and demand requires storage • (DS) yields high heat production costs: ($0.03-$0.20)/kW-hr • High-T solar thermal: currently lowest cost solar electric source ($0.12-0.18/kW-hr); potential to be competitive with fossil energy in long term, but needs large areas in sunbelt • Solar-to-electric efficiency 18-20% (research in thermochemical fuels: hydrogen, syn gas, metals) Source: Nathan Lewis

11. PV Land Area Requirements For U. S. Energy Independence • Facts: • U.S. Land Area: 9.1x1012 m2 (incl. Alaska) • Average Insolation: 200 W/m2 • 2000 U.S. Primary Power Consumption: 99 Quads= 3.3 TW • 1999 U.S. Electricity Consumption = 0.4 TW • Conclusions: • 3.3 TW /(2x102 W/m2 x 10% Efficiency) = 1.6x1011 m2 • Requires 1.6x1011 m2/ 9.1x1012 m2 = 1.7% of Land Source: Nathan Lewis

12. PV Land Area Requirements 3 TW 20 TW Source: Nathan Lewis

13. It takes .16% of the Earth’s surface to generate the Carbon Free energy needed in 2050 • 1.2x105 TW of solar energy potential globally • Generating 20 TW with 10% efficient solar farms requires: 2x102/1.2x105 = 0.16% of Globe = 8x1011 m2 (i.e., 8.8 % of U.S.A) • Generating 1.2x101 TW (1998 Global Primary Power) requires: 1.2x102/1.2x105= 0.10% of Globe = 5x1011 m2 (i.e., 5.5% of U.S.A.) Source: Nathan Lewis

14. A “Notional” Distribution Of PV “Farms” To Achieve 20 TW of Carbon Free Energy in 2050 6 Boxes at 3.3 TW Each Source: Nathan Lewis

15. How Much Energy Can Be Produced On The Roofs of Houses? • 7x107 detached single family homes in U.S. • ≈2000 sq ft/roof = 44ft x 44 ft = 13 m x 13 m = 180 m2/home or … 1.2x1010 m2 total roof area • This can (only) supply 0.25 TW, or ≈1/10th of 2000 U.S. Primary Energy Consumption • … but this could provide local space heating, surge (daytime) capacity. Source: Nathan Lewis

16. crystalline Si amorphous Si nano TiO2 CIS/CIGS CdTe Efficiency of Photovoltaic Devices 25 20 15 Efficiency (%) 10 5 2000 1980 1990 1970 1950 1960 Year Source: Nathan Lewis Margolis and Kammen, Science 285, 690 (1999)

17. Status Of Solar Photovoltaics • Current efficiencies of PV modules: • 6-9% on amorphous Silicon; 13-19% for crystaline Silicon • Performance efficiency improvement of 2X is anticipated • Increase in PV shipments (50MW in 1991; 280 MW in 2000) • Continuous reduction in investment costs up front • Rate of decline is 20%/year • Current cost is $5/Watt; target is $1/Watt (5X) • Payback time will be reduced from 3-9 years to 1-2 years • Electricity production cost prediction: • $.30 to $2.50/kWh would be reduced to $.05 - $.25/kWh • Over 500,000 Solar Home Systems have been installed in the last 10 years Source: Turkenburg, Utrecht University

18. Nuclear As An Option? • Nuclear plants do not scale well. • Typically most effective at 1 GWatt • To produce 10 TW of power … • 10000 new plants over the next 50 years • One every other day, somewhere in the world • Nuclear remains an option • Fusion power remains as a “great hope”

19. Energy Future: Options • Topics: • Hydrogen • Fuel Cells

20. Hydrogen • Widely produced in today’s world economy • Steam-methane reformer (SMR) process • Just now, beginning to successfully scale down (e.g. to be used at “gas stations” in future (100,000 places in U.S,). Source: NAE Article, The Bridge, “Microgeneration Technology”, 2003

21. Electrolysis • Hydrogen can also be made from solar power on electrolysis of water • A liquid, transportable form can be produced (methanol; (good catalysts exist to do this from CO2 )). This ends up as carbon neutral or CO. • At bulk power costs of $.03/W electrolysis of water can compete with compressed or liquid H2 (transported) • Could produce small quantities of H2 to fuel cars, even at the level of a residence

22. Hydrogen, Again • Fuel cells using Proton Exchange Membrane have made enormous progress, but are still expensive. • Hydrogen storage in carbon fiber strengthened aluminum tanks. • Hydride systems and carbon from solar power on electrolysis of water • A liquid, transportable form can be produced (methanol; (good catalysts exist to do this from CO2). This ends up as carbon neutral. • Hydrides appear to be promising as means of storing hydrogen gas

23. Is there Carbon in Hydrogen? • If used in a fuel cell, Hydrogen still produces Carbon (Dioxide) because of how it was manufactured: • 145 grams/mile if it comes from natural gas • 436 grams/mile if it comes from grid electricity • But, for context: • 374 grams/mile if it came from gasoline (no fuel cell) • 370 grams/mile if natural gas had been used directly (no fuel cell). • 177 grams/mile through hybrid vehicles (no fuel cell; with natural gas) Source: Wald, New York Times, 11/12/2003

24. Fuel Cell Technology Source: CETC

25. Fuel Cell Power Generation Is Emerging Source: Ballard

26. Energy Future: Options • Topics: • Distributed Power Generation • Spinning capacity

27. Microgeneration Technology(Distributed Generation) • 7% of the world’s energy is generated on a distributed basis • In some countries this is up to 50% • Generate power close to the load • 10 – 1000 kW (traditional power plants are 100 – 1000 MW) • Internal Combustion, Turbine, Stirling Cycle (with efficiencies approaching 40%), Solid-oxide fuel cells (over 40% efficiency), Wind Turbines, PV • Modular (support incremental additions of capacity) • Low(er) capital cost • Waste heat can be captured and used locally via Combined Heat and Power (CHP) systems • Storage technology is also moving forward to deal with localized capacity (e.g. zinc-air fuel cell). Source: NAE Article, The Bridge, “Microgeneration Technology”, 2003

28. Spinning Reserves From Responsive Loads • How to avoid significant “reserves” in power generation? • Control both generation and load: • Historically only generation was controlled • Network technology enables control of load (through management of numerous small resources) Source: Oak Ridge Research Report, March 2003.

29. Spinning Reserve From Responsive Loads(Smart Energy) Carrier ComfortChoice themostats provide significant monitoring capability - Hourly data - No. of minutes of compressor/heater operation - No. of starts - Average temperature - Hour end temperature trend - Event data - Accurate signal receipt and control action time stamp

30. Conservation • Hybrid Vehicles • Space heating • Water heating • Co-generation

31. Energy Future: Options(Policies) • Topics: • Taxes • Forced Standards • Research and Development

32. Energy Future: The EE Role • Electricity is the future • Most energy sources will come via electricity • Systems will have to be significantly more efficient, smarter: • More distribution • More connectivity (communication) • More intelligence • More information • More integration • More transparency • The entire energy infrastructure will have to be changed within 50-100 years Electrical Engineers will play a critical role in making this transition effective

33. Conclusions

34. Conclusions (Mine) • There is an “energy problem” (a “carbon problem”), an unsustainable dependence on fossil fuel • Market forces and innovation will play a major role, but are not responsive enough to deal with mass scale, current low costs of energy, and long time constants • The economic impact of a forced shift from fossil fuels is unacceptable • Policy shifts and long term investment are needed • Natural Gas to Solar is the most visible path to sustainability, today • Major, near term investment in Natural Gas infrastructure is needed • Cost of a major solar power infrastructure is daunting, but we should organize ourselves for this eventuality • Hydrogen can/will become an important transport system (start with methane derived hydrogen and move toward renewable resource driven hydrogen) • Known efficiencies can produce near term gains. E.g., Distributed power (with co-generation of heat), “smart power”, hybrids • Substantial investment in renewable energy research is justifiable • Sufficient research is needed to achieve attractive economies of scale

35. Questions and Comments