Session 7 Sustainability and Fossil Fuels

1
Session 7 Sustainability and Fossil Fuels
2
Definitions of Sustainability

• One definition
• For renewables Usage rate lt generation rate
• For non-renewables Usage rate lt sustainable use
  rate of substituted renewable
• For a pollutant Emission rate lt rate of
  recycling, absorption, or neutralization
• The ideal requires complete reliance on
  renewables.
• Another definition related to GHGs
• Sustainability means meeting energy needs w/o
  adverse warming

3
Sustainability Who Cares?

• Life is day-to-day in many countries
• However, all countries face a global market for
  primary fuels price is a force
• Pie charts, p 264 China, Middle East/Africa
  will outpace US energy use by 2095 will all
  three adopt the ideal?
• If sustainability erodes economies, can we
  maintain or improve human condition?

4
A Conundrum

• Human Development Index (HDI) of United Nations
  Humans need gt 4 MWh annually of electricity for
  well being
• Yet, the UN IPCC predicts temp rises of 1.4 to
  5.8 C by 2100
• Do we meet basic human needs and suffer climate
  change consequences, or leave needs unmet with a
  more stable environment?

5
Assessing Technology for Sustainability

• Engineering may yield an answer that is not
  mutually exclusive!
• Comparing conversion systems is difficult
• UN uses three general indicators to measure
  sustainability
• Environmental
• Economic
• Social
• Lets compare wind and nuclear using these
  indicators

6
Cornerstones of Sustainable Energy Policy
Customers (Regulatory or market-based?)
Technology (Technically feasible at required
scale? Public or private development?)
Capital (Who will invest, what risk/return profile
?)
7
Fossil Energy

• Recall About 80 of US energy is fossil 70 of
  US electricity is fossil based
• Recall Fossil coal, natural gas, petroleum
• P. 296 A fossil fuel is a substance that
  releases energy by a chemical reaction.
• This is a necessary but not sufficient definition
• Also needs to be organic, have covalently bonded
  Carbon, and be produced over geological time
  periods
• Consider how biofuels meet parts of these
  definitions

8
Fossil Energy ReservesExample from Sample
Problem 7.1

• They appear huge . . .
• for Coal, 290,000 Quads (roughly)
• World annual energy use in 1995 was 325 Q
• If rate stayed constant, and if coal used
  exclusively,
• Reserves would last for 846 years

9
Fossil Energy ReservesExample from Sample
Problem 7.1

• However, with 2 annual growth in consumption,
  reserves shrink to 144 years.
• Are reserves increasing each year?
• Are countries and reporting entities trusted
  sources for national reserves?

10
Fossil Energy ReservesNorth Dakota Lignite
Reserves

• 351 billion tons of known lignite reserves
• 25 billion tons that are economically recoverable
  good for 800 years
• 32 million tons produced annually steady
  production for a decade or more
• At 7000 Btus/pound, North Dakota reserves contain
  4.8 E 18 Btus
• or 4800 Quads
• Enough to power the world for over 10 years.

Source North Dakota Geological Survey Lignite
Energy Council