Flashcards in // lecture 35 Deck (37):
benefits of fracking
- domestic oil and natural gas production in the usa
- less dependence on imported oil
- lowers gasoline prices
- provides jobs in north dakota
willie soon: climate denier
- 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.
exxon mobil and GW denial
- 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
stabilizing atmospheric CO2 at ~500 ppm
- 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
what is a wedge?
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.
pholtovoltaic (solar) power
- 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)
- 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
- 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
carbon capture and storage
- effort needed for 1 wedge by 2055
- implement CCS at 800 GW coal electric plants
- implement CCS at 1600 GW natural gas electric plants
efficient use of electricity
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
Changing all light bulbs to CFL would be
1/3 of a wedge! now we have LEDs
CFL vs LED cost
- 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.
efficient generation of electricity
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.
efficient use of fuel
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
- eliminate all tropical deforestation
plant new forest over an area the size of the Continental u.s.
- use conservation tillage on all cropland (1600 Mha)
- leaves at least 30% of crop residue on the surface
- stores more carbon within the soil
no till agriculture
- saves energy and money
- preserves the soil
- buries carbon in soil
- can be just as productive as full tillage methods
are the wedge strategies scalable?
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
- 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.
What's appealing about wedges?
- 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
- 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
how is wind power generated?
- 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
main problem: intermittentcy
- 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).
currently small part of total - 1.3 GWatts, global
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
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
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)
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.
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
offshore wind power cons
- Not available everywhere
- Obstructs views/noise paranoia Hazard to birds? (probably not if placed away from migration zones)
- Requires large area
Solar Power types
1. Passive solar: doesn’t use mechanical or electrical
- 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
3. Solar photovoltaic
- Generates electricity directly from sunlight using
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)
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
Myth: Albedo Effect Causes Global Warming
Solar panels are dark: do they affect planetary
- Wrong! The albedo change is small and
results in a negligible amount of heating. This is not a problem.
Solar Energy and Albedo
- All the electricity in the world could be generated by
solar panels covering an area of the black box
- 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
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