Transcript Research Opportunities for Chemical Engineers in Building

The U.S. Industrial and Building Sectors
• Industrial energy usage = 35 quads; building energy
usage = 40 quads(total = 100 quads)
• Building energy consumption split roughly 50:50
between commercial and residential buildings
• These two sectors account for about 70% of total
U.S. GHG emissions
• By 2030, 16% growth in U.S. energy consumption,
which will require additional 200 GW of electrical
capacity (EIA)
• Energy efficiency goals of 25% reduction in energy
use by 2030(McKinsey and National Academies
Press reports)
1
Impacts of proposed US GHG
legislation if enacted in 2007
http://www.wri.org/climate/topic_content.cfm?cid=4265
2
Other Alternatives
• Cap and Trade
– Establishes firm limit on CO2 emissions
– Auctioning/trading of emissions permits
• Carbon Tax
– Price Predictability
– Favored by large chemical companies
– Apply to all Carbon Sources
• Regulated CO2
– Recent EPA announcement on reporting
requirements
3
CO2 Absorption/Stripping of
Power Plant Flue Gas
Use 30% of
power plant output
Flue Gas
With 90% CO2
Removal
Stripper
Absorber
Flue
Gas In
Rich
Solvent
CO2 for
Transport
& Storage
LP Steam
Lean
Solvent
4
Increased Generation Efficiency
• Conventional efficiency: 40-55%
• Cogeneration efficiencies: 75-85%
• Used by 25% of U.S. petrochemical industry
5
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
Price, Nominal dollars per million BTUs
10
How U.S. Fossil Fuel and Electricity Prices Have Varied from 19492006
9
8
7
6
5
4
3
2
1
0
Year
Natural Gas
Coal
Crude
Electricity
6
Impact of Shale (Natural) Gas
• Increasing supplies of domestic natural gas
(+20%)
• Increased usage in power generation
• Makes U.S. industrial locations more
globally competitive (feedstock, power)
• Changes regional industrial development
options (e.g., NY-PA), subject to local
environmental pressures
7
8
Optimization of Design and
Operation Can
•
•
•
•
•
•
Reduce energy consumption
Improve yields
Reduce pollutants
Increase processing rates
Increase profitability
Maximize efficiency
9
10
What is a Smart Grid?
• Delivery of electric power using two-way digital
technology and automation with a goal to save
energy, reduce cost, and increase reliability.
• Power will be generated and distributed optimally
for a wide range of conditions either centrally or at
the customer site, with variable energy pricing
based on time of day and power supply/demand.
• Permits increased use of intermittent renewable
power sources such as solar or wind energy and
increases need for energy storage.
11
Today’s Grid
Smart
Grid 1.0
12
Tomorrow’s Grid
Smart
Grid 2.0
13
Electricity Demand Varies
throughout the Day
Source: ERCOT Reliability/Resource Update 2006
14
Wind and ERCOT daily load
1.2
1
Normalized
0.8
Normalized
wind
0.6
Normailized
load
0.4
0.2
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour Ending
Source: Dispatchable Hybrid Wind/Solar Power Plant, Mark Kapner, P.E
15
Three Types of Utility Pricing
• Time-of-use (TOU) – fixed pricing for set periods
of time, such as peak period, off peak, and
shoulder
• Critical peak pricing (CPP) – TOU amended to
include especially high rates during peak hours on
a small number of critical days; alternatively, peak
time rebates (PTR) give customers rebates for
reducing peak usage on critical days
• Real time pricing (RTP) – retail energy price tied
to the wholesale rate, varying throughout the day
16
17
Smart Grid Challenges/Unknowns
•
•
•
•
•
•
•
•
•
•
Design of the grid
Power storage
Redundancy and reliability for peak/base loads
Power flow management
Power stability
Cybersecurity
Automation/decentralized control
Distributed power generation (renewables)
Power electronics
AC vs. DC
18
Future Industrial Environment
• Stronger focus on energy use(corporate
energy czars?)
• Increased energy efficiency and decreased
carbon footprint
• Increased use of renewable energy(e.g.,
solar thermal) and energy storage
• Interface with smart grids.
19
Thermal Energy Storage
• Thermal energy storage (TES) systems heat or cool a
storage medium and then use that hot or cold medium
for heat transfer at a later point in time.
• Using thermal storage can reduce the size and initial cost
of heating/cooling systems, lower energy costs, and
reduce maintenance costs. If electricity costs more
during the day than at night, thermal storage systems
can reduce utility bills further.
• Two forms of TES systems are currently used. The first
system used a material that changes phase, most
commonly steam, water or ice. The second type just
changes the temperature of a material, most commonly
water.
20
Grid Electricity
Exhaust
Facility Electricity
Auxiliary
Power
Electricity
Produced
Power
Generation
(Gas Turbine)
Electric
Chiller
Heat
Recovery
System
Heat Carrier
Storage
Tank
Input Fuel
Chiller
Power
Boiler
Chilled Fluid
Absorption
Chiller
Demand
Storage
Tank
Σ
Heat
Exchanger
Heat Carrier
Heat Carrier
Waste Heat
Electricity Flow
Fuel Flow
Thermal Flow
Energy flows in a combined heat and power system with thermal storage (Wang, et al. 2010)
Phenomena time scales in electric power systems
A typical electromechanical system