Renewable and Nuclear Energy as Appropriate Technology for Large- Scale Production of Hydrogen Fuel Paul Kruger Prof. Em. Nuclear Civil Engineering Stanford University NHA

The Fossil-Fuel Era by M. King Hubbert (1960s)

Start of Official Environmental Awareness in the U.S.A. NEPA,1969, First Law of the New Decade, Signed into law 1 January 1970 as recognition of a National Policy for the Environment Considers such Broad Problems as Population Growth Urbanization Resource Exploitation Appropriate Technology

Factors for Appropriate Technology Growth of World Population Search for Sustainable Energy Supply Growth of World Electrification Worry about Global Climate Change Desire for Reduction of Fossil-Fuel Use Need for Alternative Energy Resources Specific Energy of Available Fuels Appropriate Fuel for Scale of Application

World Population 1950 – 2004 – 2050

World Electricity Generation 1980 – 2004 – 2030

World Electric Energy Intensity 1980 – 2030 Electricity Generation Population Intensity Year (PWh) (Billion) (MWh/cap) Ratio 3.8 X 1.9 X 2.0 X

Alternative Energy Resources Terrestrial Geothermal steam Thorium and uranium ores Hydrogen isotopes: deuterium and tritium Lunar Tidal energy Solar Thermal energy Hydraulic energy Kinetic energy Photosynthesis

Specific Energy of Fuels

Appropriate Technology as f (Specific Energy) For Large Numbers of Distributed Small-Scale Applications: Low-Specific Energy Resources For Small Numbers of Central Large-Scale Applications: High-Specific Energy Resources

Renewable Energy Resources for Large-Scale Applications Geothermal –Steam: to Electric Power Solar Radiation –Biomass: to Biofuels –Potential energy: to Hydroelectricity –Kinetic energy: to Wind Power –Photovoltaic: to Electric Power

Appropriate Technology Solar PV Electricity Electric Power in Space Rural Electrification Remote Monitoring and Control Electricity Grid-Connected Systems Power Stations Building-Integrated Photovoltaic Systems Homes Commercial Buildings

Home Use of PV Electricity

PV Electricity for U.S. Homes No. Single-Unit households: 76 Million For mean PV capacity per unit: 3 kW (AC) Potential PV power capacity: 228 GW U.S. generating capacity: 813 GW Potential for solar replacement: 28 % Source: American Housing Survey – National (HUD, 2001)

Building-Integrated PV Systems PV cells → modules → arrays mostly:crystalline wafers of Silicon (Si) BIPV: thin films, e.g., amorphous Si on transparent substrates, e.g., glass Provides daylight, heat, and PV electricity as part of the structural material Requires large area to offset low conversion efficiency, Inverters to transform DC to AC current, and a Storage System (e.g., batteries or connection to a utility grid)

4 Times Square Building

One of the First BIPV systems in the USA Thin-Film arrays extend over the topmost floors on South and East facades Cover 3095 ft 2 at module weight 13.5 lb/ft 2 Generates ~ 15 kWp at module efficiency ~ 6% Produces ~ 14,000 kWh/yr

Pearl River Tower

Under construction in Guangzhou, China as a net-zero-energy skyscraper using several “green” technologies, including: 8 wind turbines on the south face; 2 arrays of solar PV cells: one on the east and west sides one on the spandrels on the south face

Development of Large-Building PV 4 Times Pearl Masdar Square River City Year installation BIdg PV area (m 2 ) Power (W/m 2 ) ~ PV system (kWp) Annual yield (MWh)

Appropriate Technology Nuclear Production of Hydrogen World vehicle fleet: 800 million by 2010; FC fleet could grow to 1.4 billion by 2050 Hydrogen fuel demand: low thru 2030; could grow to 260 billion kg/a by 2050 Electric energy demand: 35 PWh/a by 2030; could grow to 60 PWh/a by 2050 w/o H 2 Additional electricity required for hydrogen fuel could grow to 10 PWh/a by 2050.

Nuclear Production of Hydrogen Electric power for steam reforming of methane Off-Peak utilization of electricity for electrolysis of water High-Temperature electrolysis of steam Thermochemical dissociation of water

Resources for a World Electricity Supply of 70 PWh/a by Percent from Solar Energy 17.5 PWh from photovoltaic electricity Number of 5-kW(AC) installations, each generating 2000 kWh/a per kW: 1.7 Billion 17.5 PWh from wind energy Number of 5-MW wind turbines, each generating 3GWh/a per MW: 1.2 Million

Resources for a World Electricity Supply of 70 PWh/a by Percent from Nuclear Energy 35 PWh/a from Nuclear Power Plants Number of 1250-MW NPPs, each generating 10 TWh/a per NPP: 3500

Balanced Resources for a World Electricity Supply of 70 PWh/a by 2050 Electricity Supply Resource (PWh/a) (%) No. Required Solar PV billion Wind million Nuclear

Solar-Nuclear-Hydrogen Energy Parks Concept: Large-area industrial park with central cluster of nuclear power plants surrounded by field of photovoltaic arrays (and wind towers where appropriate) Mitigation of Concerns: Nuclear: unpopularity of Hi-specific energy Solar: problems of Low-specific energy Synergistic Coupling: Increased efficiency of producing electric power and hydrogen fuel at minimum cost