// lecture 35

Question 1

benefits of fracking

Answer 1

• domestic oil and natural gas production in the usa
• less dependence on imported oil
• lowers gasoline prices
• provides jobs in north dakota

Question 2

willie soon: climate denier

Answer 2

• from the harvard-smithsonian center for astrophysics scientist
• documents show that he accepted money from the fossil fuel industry to write papers for scientific journals and did not disclose the source of his funding.

Question 3

exxon mobil and GW denial

Answer 3

• formerly standard oil from which the rockefeller family made its fortune
• rockerfeller family has gone out of its way to show that
• exxon mobil worked to deny climate change, even though they knew based on numerous briefings from their own scientists that it was a serious problem directly related to fossil fuel use
• they undertook a program to deny and obfuscate the facts

Question 4

stabilizing atmospheric CO2 at ~500 ppm

Answer 4

• in 2004, Pascala and Socolow proposed a scheme to achieve this goal
• phase 1: no further increase in emissions until 2054, with energy production still increasing rapidly. ramping up existing technologies to do this.
• phase 2: after 2054, rapid reductions in global emissions. final emissions of all GHGs must level off by ~2100 to ~1.5 Gt/yr or ~20% of present global emissions

Question 5

what is a wedge?

Answer 5

a wedge is a strategy to reduce carbon emissions that grows in 50 years from zero to 1.0 GtC/yr so total 25 gigatons of carbon reduced.

Question 6

pholtovoltaic (solar) power

Answer 6

• effort needed for 2055 for one wedge:
• 2000 GW (peak) - 700 times current capacity
• 2 million hectarces (about 12% the size of WA): roofs can be used though
• would require 14% increase per year (we’re currently increasing at 30% per year)

Question 7

nuclear electricity

Answer 7

• effort needed by 2055 for 1 wedge: 700 GW displacing coal power.
• No new nuclear power plants have been built in the US for a long time, because of Three Mile Island and Chernobyl problems. Problem with waste disposal. NIMBY

Question 8

fuel switching

Answer 8

• effort needed by 2055 for 1 wedge
• substitute 1400 natural gas electric plants for an equal number of coal fired facilities
• one wedge requires an amount of natural gas equal to that used for all purposes today

Question 9

carbon capture and storage

Answer 9

• effort needed for 1 wedge by 2055
• implement CCS at 800 GW coal electric plants
• implement CCS at 1600 GW natural gas electric plants

Question 10

efficient use of electricity

Answer 10

effort needed by 2055 for wedge:

• Use best efficiency practices in all residential & commercial buildings
• 25% - 50% reduction in expected 2055 electricity use in commercial and residential buildings

Question 11

Changing all light bulbs to CFL would be

Answer 11

1/3 of a wedge! now we have LEDs

Question 12

CFL vs LED cost

Answer 12

• cost about a factor of 2, but life time is factor of 5

and energy efficiency is factor of 2. So if you are going to keep it for long enough, get the LED.

Question 13

efficient generation of electricity

Answer 13

Effort needed by 2055 for 1 wedge:
- Improve the efficiency of coal power plants from 40% to 60%, and double efficiency from which we take fossil fuels from the ground.

Question 14

efficient use of fuel

Answer 14

effort needed by 2055 for 1 wedge
- decrease the number of miles drive per car: 5,000 instead of 10,000 mi per year

effort needed by 2055 for 1 MORE wedge
- double fuel efficiency of cars: 60 mpg instead of 30 mpg

Question 15

deforestation

Answer 15

• eliminate all tropical deforestation

Question 16

reforestation

Answer 16

plant new forest over an area the size of the Continental u.s.

Question 17

conservation tillage

Answer 17

• use conservation tillage on all cropland (1600 Mha)
• leaves at least 30% of crop residue on the surface
• stores more carbon within the soil

Question 18

no till agriculture

Answer 18

• saves energy and money
• preserves the soil
• buries carbon in soil
• can be just as productive as full tillage methods

Question 19

are the wedge strategies scalable?

Answer 19

can the wedges keep growing?

• are the first million two-megawatt wind turbines more expensive or cheaper than the second million two-megawatt wind turbines?
• The first million will be built at the more favorable sites.
• But the second million will benefit from the learning acquired.

The question generalizes to almost all the wedge
strategies:
- Geological storage capacity for CO2, land for biomass, river valleys for hydropower, uranium ore for nuclear power, semiconductor materials for photovoltaic collectors.
- First ones are the low-hanging fruit, but then you learn to pick the fruit more efficiently.

Question 20

What’s appealing about wedges?

Answer 20

• the stabilization triangle
• • does not concede doubling CO2 is inevitable
• • shortens the time frame to within business horizons
• the wedge
  – Decomposes a heroic challenge (the Stabilization Triangle) into a limited set of heroic tasks
  – Establishes a unit of action that permits quantitative
  discussion of cost, pace, risk, trade-offs, etc
• The wedge strategy
• • Does not change the fact there are winners (alternative
    energies) and losers (coal and oil become more expensive sources of energy), but brings many options to the table

Question 21

wind power

Answer 21

• rapidly growing in Europe (denmark, germany, and spain) and the US (TX, IA, CA, OR, WA). still very underutilized.
• We are the Saudi Arabia of wind. Could provide 9 times US electricity usage just in lower 48

Question 22

how is wind power generated?

Answer 22

• wind blows past a turbine (like a propeller) and turbine is turned, which makes energy and power is produced which is proportional to wind velocity

Question 23

main problem: intermittentcy

Answer 23

• wind doesn’t always blow
• currently this isn’t a huge problem bc wind doesn’t provide most of the electricity anywhere but it could become more a problem in the future (nuclear/hydro/geothermal etc as backup). denmark deals with this by selling excess power to Norway
• having a grid connecting distributed wind farm sites can help ensure that the wind is blowing somewhere
• solar power tends to be complementary to wind in
  midlatitudes (windier in winter, sunnier in summer).

Question 24

renewable energy

Answer 24

currently small part of total - 1.3 GWatts, global

Question 25

in WA we have hydro power

Answer 25

• about 7% of the u.s. electricity comes from hydropower, this is 67% of WA’s electricity
• extremely expensive to build
• possible extreme environmental damage to flooded area and fish migration
• not likely to see more dams built in the u.s.
• Actually removed Elwha Dams on the Olympic Peninsula for wildlife reasons – all 5 species of Pacific Salmon. Finished removal summer 2014

Question 26

wind power myths/fears

Answer 26

• harms birds? all human structures harm bird life but wind farms are an extremely small fraction of the harm to birdlife and careful placement away from migration patterns can help
• aesthetics? cape wind was long delayed due to concerns about views

Question 27

Wind Electricity

Answer 27

One million 2-MW windmills displacing coal power: - Would require land space the size of Montana (but land below could be used for grazing, farmland, etc)
- Wind energy would only have to increase by 8%
per year to achieve this (and recent increases have been 30% per year)

Question 28

biofuels

Answer 28

Effort needed by 2055 for 1 wedge:

• 2 billion 60 mpge cars running on biofuels instead of gasoline and diesel.
• To produce these biofuels: 250 million hectares of high-yield (15 t/ha) crops, one sixth of world cropland.

Question 29

offshore wind power pros

Answer 29

• Produces no greenhouse gases after windmill is constructed
• Decentralized production
• Moderately priced in the long term compared to fossil fuel
• Can use land underneath

Question 30

offshore wind power cons

Answer 30

• Intermittent
• Not available everywhere
• Obstructs views/noise paranoia Hazard to birds? (probably not if placed away from migration zones)
• Requires large area

Question 31

Solar Power types

Answer 31

1. Passive solar: doesn’t use mechanical or electrical
   equipment
   - Uses sunlight to reduce heating/lighting/ventilation costs E.g., south-facing windows (in Northern Hemisphere) for more winter sunlight
2. Solar thermal collection
   - Produces hot water or warm air for homes, industry, or
   electricity generation
3. Solar photovoltaic
   - Generates electricity directly from sunlight using

Question 32

Type 2: Solar Power Towers (collector)

Answer 32

“Power tower” plant outside Madrid: mirrors heat steam in the central tower that drives a turbine (11 MW peak)

Question 33

Type 3: Photovoltaics

Answer 33

• “Photovoltaic” solar cells
• Growing rapidly in Europe and Japan
• Expense has been issue: uses pricey raw materials. Subsidies have been to make these economically viable. Prices are falling though
• Especially good for developing countries (can be installed one house at a time). Initial investment lower than coal plant per kwh

Question 34

Myth: Albedo Effect Causes Global Warming

Answer 34

Solar panels are dark: do they affect planetary
albedo?
- Wrong! The albedo change is small and
results in a negligible amount of heating. This is not a problem.

Question 35

Solar Energy and Albedo

Answer 35

• All the electricity in the world could be generated by
  solar panels covering an area of the black box
  below
• Total extra absorbed radiation if panels are above desert: 0.01 W/m2 (compare with 4 W/m2 for doubling CO2)
• Solar panels can also be installed on dark roofs

Question 36

solar energy pros

Answer 36

•   Produces no greenhouse gases after panel is installed - Unlimited
• Long lasting (low maintenance cost)
• Peak production in-sync with demand (we don’t need as much power at night)
• Decentralized production

Question 37

solar energy cons

Answer 37

• Expensive now
• Somewhat limited by location (deserts are gold mines for solar energy, but storing/transporting the power is expensive/inefficient at present – needs a smart grid.)