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EECS4460.129.22.19.pptx
Power System Management
EECS 4460/5460-901
Lecture #12
Power Systems and the Environment
1
Generation: 8652 power plants in the U.S.
Over 1.2MMw of Capacity (plants greater than1MW)
Over 20,000 individual generating units
Transmission: 600,000 circuit miles
240,000 miles at 230Kv and above
Substations: Over 55,000 substations
Distribution: Over 5.5 million circuit miles
Customer Interfaces
Over 151Million Customer Facilities and Connections
Generation, Transmission and Delivery of Electricity Clearly Impacts the Environment
Fossil Power Plant Emissions
CO2 is a greenhouse gas, which contributes to the greenhouse effect.
SO2 causes acid rain, which is harmful to plants and to animals that live in water. SO2 also worsens respiratory illnesses and heart diseases, particularly in children and the elderly.
NOx contribute to ground-level ozone, which irritates and damages the lungs.
PM (Particulate Matter) results in hazy conditions in cites and scenic areas and coupled with ozone, contributes to asthma and chronic bronchitis, especially in children and the elderly. Very small, or fine PM, is also believed to cause emphysema and lung cancer.
Heavy metals such as mercury are hazardous to human and animal health.
EPA: National Ambient Air Quality Standards (NAAQS) and 1990 Clean Air Act by EPA
Reduce Particulate levels (first set in 1971)
Reduce major emissions in sulfur dioxide (SO2) and nitrous oxides (Nox)
Cross State Air Pollution Role (CSAPR)
Mercury and Air Toxics Standards (MATS)
Regulations
Particulate Reduction: Electrostatic Precipitators
First applied in 1923
99% Efficiency
Handles large volumes with low pressure drop
Particulate Reduction: Electrostatic Precipitators
Particulate Removal Progress (all sectors)
SO2 Removal By “Scrubbers”
Technically Flue Gas Desulfurization
Pollutants are “washed” from the flue gas
Wet – Liquid spray, water and
Calcium carbonate (limestone); waste
product is gypsum
Dry- Chemicals neutralize pollutants; residual waste is hazardous
Also helps remove acid gases(HCl)
Simplified Wet Scrubber
NOx Removal: Selective Catalytic Reduction (SCR)
Today’s Power Plants…..
EPA – 1990 Clean Air Act Amendments MATS (Mercury and Air Toxics Standards)
Covered Toxic Air Pollution:
Mercury, Non-mercury toxic metals, Acid gases and Organic Air toxins
Activated Carbon Injection to Remove Mercury and Air Toxics
Mercury Compliance Achieved by Activated Carbon Injection Systems
Regulations and Emission Reductions from Power Generation
Reductions Continue
Coal Emissions Have Declined
Across the Country – All Sectors
Compliance Takes Time and Money
Emission Projections – Continued Decline
CARBON
CO2 is the primary
greenhouse gas
It is 84% of U.S.
greenhouse gas
emissions
CO2 Emission Coefficients
| Lbs of CO2 emitted per Million Btu | |
| Coal - Anthracite | 228.6 |
| Coal – Bituminous | 205.7 |
| Coal – Subbituminous | 214.3 |
| Coal – Lignite | 215.4 |
| Natural Gas | 117.0 |
Carbon Capture
Post-Combustion Process: Absorbed C02 liberated from the solvent
(e.g. ammonia) and compressed for
transportation and storage
Carbon Capture in Operation
240MW, Petra Nova (TX) Post Combustion CO2 Capture
DOE Project funded at $190M
90% Carbon Reduction
Captured carbon is released into mature reservoirs to release oil
Sequestration Options
CO2 Emissions Have Reduced Long-Term
U.S. Carbon Emissions in 2018 by Sector
| Residential | Commercial | Industrial | Transportation | Electric Power | Total | |
| Coal | 0 | 2 | 101 | 0 | 1150 | 1259 |
| Natural Gas | 274 | 191 | 538 | 46 | 581 | 1630 |
| Petroleum | 65 | 60 | 357 | 1866 | 21 | 2369 |
| Other 1 | 11 | 11 | ||||
| Electricity2 | 679 | 638 | 442 | 4 | ||
| TOTAL | 1018 | 891 | 1444 | 1915 | 1763 | 5268 |
Data is Million Metric Tons of CO2
1 – Combustion waste materials and geothermal
2 – Electricity sales to other sectors and the emissions
associated with the generation of that electricity
Water Quality
Land Use
State and Local Requirements
Transmission and Distribution Impacts
Global Picture and Climate Change
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