// lecture 36 Flashcards
American Energy Innovation Council
Led by people like Bill Gates. Published report stating that US government is not spending enough money on research into energy sources. Claim that fracking bonanza was in part a result of government funded research.
World’s Large Solar Energy Plants
- IvanPah in the Mojave Desert of CA (SW of Las
Vegas, NV on road to LA) produces 377 Mega Watts (MW) 400,000 homes worth. - Built between 2010 and 2013. Three towers have
been built and are operating.
Solar Revolution
Dewa 13 plant in UAE, south of Dubai, 13MW
geothermal power
Taps into hot rocks under the surface of the Earth (This heats water, makes steam to turn turbines).
- US is top producer (2.5 GW) in terms of total capacity (CA, NV, UT)
- Over 15% of the electricity generation in Iceland, Philippines, El Salvador, Costa Rica, and Kenya
- Very steady source (no problems with intermittency)
geothermal energy pros
- Reliable Supply
- Relatively Simple Facilities
- Inexpensive
- Small surface footprint compared to wind and solar
geothermal energy cons
- Regionally limited
- Releases a little CO2 and other more harmful gases from underground
- Enhanced geothermal systems have caused seismic activity during construction
one way to generate nuclear power
1) heat water
2) which makes steam
3) which can turn a turbine.
nuclear power
- Huge in France (80% of electricity there)
- Over 100 plants in the US. No new constructions since 1970s. Obama administration recently approved $8 billion for loans for new plants.
- Many see a “nuclear renaissance” to help move towards
carbon zero energy
Nuclear Power Problems
- New plant construction is rather expensive ($9 billion?)
- Waste disposal remains an issue: Highly radioactive material is produced that must be kept away from life forms. Short term storage on-site, but long term storage? Reprocessing can help but this produces plutonium (can be used in weapons).
nuclear energy pros
- Produces no greenhouse gases
- Available 24 hrs/day
- Plenty of Uranium in US
nuclear energy cons
- Expensive to build facilities
- Storage of extremely hazardous radioactive wastes
- Requires lots of water
- Relationship to weapons (concerns about proliferation)
Carbon Capture and Storage
- Works for CO2 emitted from Coal and Natural Gas Plants, but not applicable to non-point sources (e.g., CO2 emitted from tailpipes).
- Makes energy from coal expensive compared to many other sources, including renewables.
- Risky if CO2 escapes from storage.
Carbon Capture and Storage (CCS)
- Pumping gases into oil or natural gas fields is sometimes done anyway to increase oil field productivity. Oil companies love this solution.
- Requires a large amount of energy. Increase the fuel needs of the plant by 25-40%.
- Could up to double the cost of energy from coal.
“Clean Coal” is not the same thing as Carbon Capture and Storage
- May include among the following:
• Wash coal to remove harmful chemicals
• Gasify coal by heating it to release and capture SO2, some CO2 is released and often pumped into depleted oil and gas fields to create pressure
• Produce Synfuels, which are burnt later (releasing CO2 later) - When people use this term they aren’t necessarily talking about reducing CO2 emissions at all!
Coal Power in the Pacific NW
WA and OR plants are switching to Natural Gas
Oregon’s only coal plant (Boardman power plant)
recently announced it would close by 2020:
- Biggest source of CO2, nitrous oxide, and sulfur dioxide
pollution in Oregon
- Closing would be 20 years earlier than planned (to avoid installing pollution controls)
Centralia Power Plant is the only coal plant in
Washington:
- 10% of WA emissions, also lots of mercury, sulfur dioxide, etc
- WA state senate approved a bill to support an agreement to switch it entirely away from coal by 2025
Centralia Washington Coal Power Plant
- Centralia, WA also had a coal mine
- Coal mining stopped in November of 2006
- Coal now comes from Powder River Basin (WY)
Combined Cycle Gas Turbine
- A jet engine that runs on methane, with a steam turbine
to get electricity out of the waste heat. - Exhaust from gas turbine, heats water for steam turbine.
Two stages more efficient than one. 55-59% - 270 MW gas turbine coupled to a 130 MW steam turbine
giving 400 MW in total is typical
Combined Cycle Gas Turbine
- Brayton Cycle - gas turbine
- Rankin cycle - steam turbine
Exhaust from Gas Turbine heats water for steam turbine.
Gas turbine
Spinning axis shaft drives an electricity generator
Steam Turbine
Spinning axis drives an electricity generator
Other problems with coal
In addition to CO2 emissions, other problems include: Coal mining disasters, Black lung disease in miners, Respiratory concerns with air quality, Haze, Acid rain (from the sulfate emissions), Biggest mercury source into the air, Mountaintop removal/aesthetic concerns, Water usage in mines, Water quality near mining areas, Impacts on forests/wildlife/fish.
These problems vary significantly among mines/plants/
countries. Because of massive reserves, coal is likely going to be the main future problem with global warming
More Bad Ones for the Environment…
What are some other worst offenders for
greenhouse gas emissions/environmental problems?
- Tar sands (AKA oil sands): extremely large quantities in
Canada and Venezuela
- Oil shale: major deposits in the USA
tar sands
- Lots of Tar Sands in Alberta, Canada.
- Mixtures of sand, water & a dense form of petroleum
- Harmful to the environment: Strip mining destroys large amounts of forests and Conversion process requires lots of water and energy (2-5 barrels of water needed to make a single barrel of oil, 2 tonnes of raw sands per barrel of oil, Up to 5 times as much CO2 emissions in extraction/refinement: Well-to-pump has 30-70% more emissions on average).
- 44% of Canadian production is from tar sands (esp. in
Alberta): Just became the #1 single source of US crude oil imports in 2010 (around 10% of total imports). Projected to be 20-30% of imports by 2030
oil shale
- Carbonate rock rich in “kerogen” which is usually
refined to convert to fuel. - Environmental concerns with this as well: Open-pit mining & waste management issues, 1-5 barrels of water used per barrel (in relatively dry areas), andCO2 emissions similar to worst forms of coal
Problems with oil
In addition to CO2 emissions, other problems include
- Oil spills
- Benzene & other hydrocarbons in crude & gasoline are highly carcinogenic
- Contamination of runoff/soils
- Carbon monoxide pollution
- Uncombusted fuel air quality issues
- Bad ozone pollution (from NOx)
- Smog/particulate matter polution
- Respiratory problems (asthma, irritation, etc ) associated w/ the above 4
- In the US, mostly comes from foreign sources
- Connection to totalitarian regimes
- Could hit “peak oil” soon which would greatly increase prices
Also these issues vary hugely with regions/regulations
Clean Air Act has greatly reduced air pollution in the US!
Oil Train Derailment
Train carrying North Dakota fracked oil derails and
explodes in West Virginia
Fossil Fuels and Air Quality
- It has been estimated that the current healthcare
costs that result from our use of fossil fuels exceeds the cost of converting to carbon-free fuels in order to
avoid a 2˚C warming. - This is true both in the developed world, where we
live longer and where healthcare is expensive, and in developing countries where life expectancies are shorter and healthcare is less expensive and less
available.
India and Air Quality
- A recent paper in Economic and Political Weekly
claims that levels of air pollution in India are cuusing more than half of India’s 1.2 Billion population to die
sooner than expected. - 660 million live in areas where the fine particulate
matter exceed India’s national air quality standard. - Decrease in life expectancy of 3.2 years.
- 3.2 years times 660 million people equals 2.1 Billion
life years.
More harm from Air pollution
- In addition to life span losses, air pollution results in
more sickness during life and less human productivity. - A 2013 paper published the Proceedings of the National
Academy of Sciences showed that in 2010 the wheat yield was decreased by 36% and rice yields a fifth of what they would have been if pollution was kept in check. This decline in farm productivity was attributed to black carbon related to biomass and fossil fuel burning and to elevated levels of ozone caused by the production of NOx related to burning. - This is BEFORE any agricultural harm from warming is
factored in.
The Hidden Costs of Fossil Fuels
- The healthcare, climate change and other costs of
Fossil Fuel use are generally not born by the producers of fossil fuels and passed along to
consumers. - This represents a huge subsidy of the fossil fuel
industry by the current healthcare system and by the future.
2009 National Research Council Study
- Hidden Costs of Energy
- Tried to quantify the non-climate external costs of fossil fuels.
- External costs are those not
normally included in the competitive marketplace. They focused on non-CO2 air pollution, mostly Particulate Matter, SO2 and NOx. Health damages dominated the monetization. - Congress directed the US Department of the Treasury to request this study from the NRC – the Nation’s science think tank
- Considered costs for 2005
- 406 Coal-electricity plants $62 Billion in external costs, about 3.2 cents per kW-hour, ranging
from 0.5 to 12 cents a KW-hour mostly depending on the technology for scrubbing SO2. - 498 Natural Gas-electricity plants 0.16 cents per kW-hr – much less than coal.
- Transportation vehicle sector about $56Billion or 1.5 cents per mile.
- Total of mostly health-related costs about 120$B a year an underestimate because of all the things it does not consider (damages due to some pollutants, climate change, ecosystems, infrastructure and security.)
Transportation Emissions in WA
- Because we have clean electricity, a large percentage
of WA’s GHG emissions are from transportation (45%)
- Huge improvements in our footprint can be made by
switching cars to hybrid/electric cars
Kicking the Oil Habit: Hybrids/Electrics
- Hybrid electric vehicles run off of two propulsion
systems: internal combustion & electric - Environmental concerns: Requires large battery packs, which have toxic materials in them and Some rare materials used are becoming more scarce, harder to
obtain.
Electric and Hybrid Cars
- Lots of choices now. Sometimes expensive,
sometimes limited range. - Hybrid – Gas motor drives battery, can also capture
energy going downhill or braking - Hybrid – plug in You can plug it in at night
- Electric Vehicle – no gas engine, just plug it in.
Charging Time
- Level 1 : 110 Volts 9-hours 40mile Volt
- Level 2 : 220 Volts 6-8 hours full charge
- Level 3 : DC Quick-Charge 40 miles, 10 minutes.
What is Ethanol?
Ethyl Alcohol (the drinkable kind of alcohol)
• Produced from carbohydrates and yeast
• Sweet, simple carbohydrates ferment most easily (cane sugar is best, wood pulp is harder)
Ethanol Here and Worldwide
Huge in Brazil (25% of their fuel). From sugar cane
• We make more in the US, but from corn. Much less efficient than sugar cane – high carbon footprint
• Cellulosic ethanol (e.g., from switchgrass)
would be much better for carbon footprint. Easy to grow, doesn’t require as much plowing, etc. Harder to get to ferment though (more expensive)
What is Biodiesel?
Methyl or ethyl esters
• Formed by transesterfication:
alcohol + oil –> less alcohol + biodiesel + fertilizer + glycerin
• Oil source: soybean oil, canola oil,
restaurant grease. biodiesel smells like french fries because esters are aromatic!
Biofuel Use Today
- in 2008, Americans consumed 9.6 billion gallons of ethanol, which reduced gasoline consumption by less than 5%
- Most gasoline has some ethanol in it
- E10 is Gasoline with 10% ethanol content by volume. E85 is 85% ethanol and 15% gasoline, and it is mostly sold in the Midwest.
- The energy content of ethanol is about 33% less than “pure” gasoline, so your vehicle mileage may decrease by up to 3.3% when using E10.
- Currently, you must have a “flex-fuel” vehicle to use gasoline with an ethanol content greater than 10% because ethanol takes more energy to vaporize. Can be hard to start in the cold
biofuel pros
- Reduces NET CO2 emissions (CO2 is emitted but it came from plants which recently took that CO2 from the air!)
- Better for human health reduced carbon monoxide and particulate emissions.
- Less unburned hydrocarbon emissions
- Reduced acid rain potential no sulfate emissions
- Energy independence
biofuel cons
- May be worse for human health in some ways via NOX
emissions (a key bad ozone creator) - Expensive
- Less land for food production people compete with
machines for food - Pure/high ethanol is not approved for most cars okay
as an additive
Hydrogen Fuel Cells – make electricity
Like a battery but uses oxygen from the air. Needs a steady supply of the fuel, which is H2
how do hydrogen fuel cells work?
2H2 + O2 –> 2H2O + energy
catches of hydrogen fuel cells
The Catches
• Where do you get H2?
– not naturally occurring in large quantities
• H2 can be generated via electrolysis
– 2H2O + energy –> H2 + 2O2 – Requires lots of energy
• H2 can be generated from methane
– requires energy and produces CO2
• How is H2 stored? it takes up a lot of space
– Fuel tank many times bigger than car – Transport may be difficult too
Hydrogen is a carrier of energy, not a source
