Energy

1

• Energy
• Renewable
• Biomass and Waste
• Biomass fuels include residues from logging mill
  operations processing of wood, pulp, paper,
  fiberboard agricultural crops livestock and
  poultry operations food processing demolition
  (urban wood waste)
• Waste fuels include combustible residues from
  industrial processes, municipal solid liquid
  wastes
• Currently supplies 15 of electricity production
  worldwide, more in developing countries
• Benefits
• Readily available fuel
• Inexpensive
• Reduces waste stream
• Concerns
• Emissions Especially for waste combustion
• Low fuel density
• Technology still being developed (mainly
  emissions)

2

• Energy
• Renewable
• Geothermal
• Heat from deep within earth captured and used to
  turn an electric generation turbine
• Benefits
• Inexpensive
• Minimal environmental impact Little pollution
• Energy security US has extensive resources
• Concerns
• Limited use geographically
• Not truly renewable (water injection can prolong
  life of geyser field)
• Geothermal emissions may include CO2 and H2S, as
  well as various toxic compounds
• Not economically viable in most areas
• Geological risks

3

• Energy
• Renewable
• Fuel Cells
• Many types
• All have membrane that only allows positively
  charged particles to cross and external shunt
  that channels electrons
• Have been used for decades (powered manned space
  flights)
• Benefits
• Low emissions
• Highly efficient (up to 85 in some cases)
• No moving parts Enhances durability, simplifies
  maintenance
• Energy security Can be produced anywhere
• Concerns
• Technology still in its infancy
• Energy input during processing
• Risks of handling hydrogen and other fuels
• Currently very expensive

www.fuelcells.org
4

• Energy
• Renewable
• Biofuels
• Bioalcohols
• Biodiesel
• Biogas
• Benefits
• Renewable
• Energy security
• Reduced waste stream for raw materials
• Reduced environmental impacts vs. other energy
  sources
• Concerns
• Food vs. Fuel Elevated food prices
• Not carbon neutral or carbon negative
• Growing crops processing for fuel requires land
  and water
• Pesticides may contaminate local aquifers
• Emissions from biofuels (air pollution)

5
Gibbs et al. 2008
6
Righelato and Spracklen 2007
7
US EIA
8

• Energy
• Renewable
• Other
• Tidal energy
• Wave energy
• OTEC (Ocean Thermal Energy Conversion)
• Fusion

9

• Fresh Water
• Historically limiting factor in arid regions
• 1940-1990
• World population more than doubled
• 2.3 billion ? 5.3 billion
• Per capita water use doubled
• 400 m3 person-1 year-1 ? 800 m3 person-1 year-1
• Global water use increased fourfold
• 2000 USA 2000 m3 person-1 year-1 (1450 gal
  day-1)
• Current Status
• In 1996, world human population using estimated
  54 of all accessible fresh water in rivers,
  lakes, aquifers
• Many people predict disastrous consequences for
  worlds fresh water supply in coming years
• This potential disaster may have several causes

10

• Fresh Water
• Current Status
• Distribution
• Uneven compared to population
• 75 of annual rainfall in areas containing less
  than one-third of global population
• Amazon River carries 20 of global runoff through
  area containing 10 million people
• Congo River carries 30 of Africas runoff
  through area containing 10 of population
• Uneven in space
• North America contains 19,000 m3 per person per
  year vs. 4700 m3 per person per year in Asia
• lt10 of Mexico supplies gt50 of annual runoff
• Uneven in time
• India gets 90 of annual rainfall during summer
  monsoon season (Jun-Sep) runs off too rapidly
  for efficient use

11

• Fresh Water
• Current Status
• Usage patterns
• Agriculture 69
• Industry/Energy 23
• Domestic 8
• Varies among regions and with development
• Africa 88 for agriculture (irrigation)
• Europe gt50 for industry
• Japan Industrial but uses lots of water for
  growing rice
• Spain/Portugal Arid use water heavily for
  agriculture
• Personal use tracks standard of living
• Africa 17 m3 year-1 (12.3 gal d-1)
• Asia 31 m3 year-1 (22.4 gal d-1)
• UK 122 m3 year-1 (88.3 gal d-1)
• US 211 m3 year-1 (153 gal d-1)
• By 2020, water shortages likely in Ethiopia,
  India, Kenya, Nigeria, China (parts of China
  already face problems)
• Mexico City uses groundwater for 80 of municipal
  water supply

12

• Fresh Water
• Current Status
• Contamination
• Numerous examples worldwide
• Biggest source Agriculture
• Europe Over 90 of rivers have elevated
  nutrient levels from agrochemicals
• Hungary Nearly 40 of well fields contaminated
• Developing countries On average, 90 to 95 of
  all domestic sewage and 75 of all industrial
  waste discharged into surface waters without
  treatment
• Impacts
• Nile River Diverting water retention of
  sediment behind dams has caused fertile delta to
  shrink
• Rhine River Lost 8 of 44 fish species 25 more
  endangered
• Lake Chad Diversion drought has caused
  shrinkage from 25,000 to 2,000 km2 in 30 years
  Link
• Aral Sea Diversion for agriculture has caused
  severe shrinkage, with environmental health
  problems L1 L2

13

• Fresh Water
• Possible Solutions
• World may have enough fresh water but inadequate
  distribution mechanism
• Long pipelines and movement of icebergs have been
  proposed
• Excessively expensive
• Technological limitations

14

• Fresh Water
• Possible Solutions
• Improved irrigation efficiency
• Drip irrigation reduces losses from evaporation
• Cuts water use by 40-60 compared to conventional
  systems
• Used on lt1 of irrigated land worldwide but used
  extensively in some countries (Ex Israel uses
  DI on 50 of irrigated land)
• Low-energy precision application (LEPA) methods
  apply water directly to plants
• Can lower use of water and energy (20-50)
• Municipal conservation
• Infrastructural losses can be substantial
• Ex 40-70 of water lost in transit in 15 major
  Mexican cities (similar rates in India)
• Ex Djakarta, Indonesia could cut water losses
  an estimated 20 by fixing leaky distribution
  pipes would save 12 billion gallons of water a
  year, enough to supply 800,000 people
• Higher price could encourage conservation
• Ex Bogor, Indonesia increased water prices
  3-4x average household water use dropped by 30
  in less than one year

15

• Fresh Water
• Possible Solutions
• Reuse of urban wastewater
• Use of treated wastewater for irrigation
• Today, at least half a million hectares in 15
  countries are being irrigated with gray water
• More water-efficient industry
• Practiced in industrialized nations.
• Amount of water needed to produce a ton of steel
  ranges from 23 to 56 m3 in China, compared to an
  average of less than 6 m3 in US, Japan, and
  Germany
• Desalination
• 2010 Over 20 billion gallons of fresh water
  produced daily in 15,000 facilities worldwide
• Minimum cost 0.2 gal-1
• Current methods of desalination driven almost
  entirely by combustion of fossil fuels
• Solar powered desalination plants produced only
  1.4 million gal d-1 in 2009