// lecture 35 Flashcards
1
Q
benefits of fracking
A
- domestic oil and natural gas production in the usa
- less dependence on imported oil
- lowers gasoline prices
- provides jobs in north dakota
2
Q
willie soon: climate denier
A
- 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.
3
Q
exxon mobil and GW denial
A
- 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
4
Q
stabilizing atmospheric CO2 at ~500 ppm
A
- 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
5
Q
what is a wedge?
A
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.
6
Q
pholtovoltaic (solar) power
A
- 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)
7
Q
nuclear electricity
A
- 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
8
Q
fuel switching
A
- 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
9
Q
carbon capture and storage
A
- effort needed for 1 wedge by 2055
- implement CCS at 800 GW coal electric plants
- implement CCS at 1600 GW natural gas electric plants
10
Q
efficient use of electricity
A
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
11
Q
Changing all light bulbs to CFL would be
A
1/3 of a wedge! now we have LEDs
12
Q
CFL vs LED cost
A
- 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.
13
Q
efficient generation of electricity
A
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.
14
Q
efficient use of fuel
A
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
15
Q
deforestation
A
- eliminate all tropical deforestation
16
Q
reforestation
A
plant new forest over an area the size of the Continental u.s.
17
Q
conservation tillage
A
- use conservation tillage on all cropland (1600 Mha)
- leaves at least 30% of crop residue on the surface
- stores more carbon within the soil
18
Q
no till agriculture
A
- saves energy and money
- preserves the soil
- buries carbon in soil
- can be just as productive as full tillage methods
19
Q
are the wedge strategies scalable?
A
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.
20
Q
What’s appealing about wedges?
A
- 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
- Does not change the fact there are winners (alternative
21
Q
wind power
A
- 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
22
Q
how is wind power generated?
A
- 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
23
Q
main problem: intermittentcy
A
- 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).
24
Q
renewable energy
A
currently small part of total - 1.3 GWatts, global
25
in WA we have hydro power
- 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
26
wind power myths/fears
- 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
27
Wind Electricity
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)
28
biofuels
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.
29
offshore wind power pros
- Produces no greenhouse gases after windmill is constructed
- Decentralized production
- Moderately priced in the long term compared to fossil fuel
- Can use land underneath
30
offshore wind power cons
- Intermittent
- Not available everywhere
- Obstructs views/noise paranoia Hazard to birds? (probably not if placed away from migration zones)
- Requires large area
31
Solar Power types
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
32
Type 2: Solar Power Towers (collector)
“Power tower” plant outside Madrid: mirrors heat steam in the central tower that drives a turbine (11 MW peak)
33
Type 3: Photovoltaics
- “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
34
Myth: Albedo Effect Causes Global Warming
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.
35
Solar Energy and Albedo
- 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
36
solar energy pros
- 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
37
solar energy cons
- 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.)
