Transcript Slide 1

EESOM: Electrical Energy Sourcing Optimization Model
Energy Demand
The Simplified Model
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Electrical energy demand – the actual amount of energy
consumed – is measured in Watt-hours (Wh), which
measures generating capacity at any single moment.
min( ( ( TC  X A, B,C ))  ( ( H A, B  GC  X A, B,C )))
A1 B 1 C 1
A1 B 1 C 1
Subject to:
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Land Constraint
Limited amount of land available
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AUTHORS : GROUP 11
Jayson Bowlsby ESE ’09
Shana Hoffman ESE ’09
Nick Perkins ESE ’09
Michael Rovito ESE ‘09
ADVISORS: Dr. John Keenan,
Peter Scott & Walter Sobkiw
Figure 2: Daily Load
Figure 3: Annual Load
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Demand Relative to Peak
Natural Gas
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Reg 3
Reg 4
40
20
•
Reg 6
60
Reg 2
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•
•
Reg 1
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3
5
Region 1 to Region 2
581 Miles
2.8% Loss
$16MM/GW
The True-Cost of Energy Transport
•
Reg 5
4
0
EESOM divides the US into 6 regions approximately equal and
square in area (Figure 1)
Transport costs are a function of distance and amount of energy
transported between the centroids of the regions (Figure 1)
Regional supply and demand are represented at each centroid
EESOM uses high voltage DC (HVDC) wires to transport electricity
between regions
HVDC wires require large capital investments but have lower
attenuation (gradual dissipation of energy) than AC lines
Jan Mar May Jul Sept Nov
• Cost: 10.24 - 13.39 ¢/KWh
• Capacity: 0.026 - 0.019 MW
• Output: 6.7 - 3.6 GWh/yr
• Area: 0.032 acres
Concentrated Photovoltaic; 30%
Efficiency; Single Module
Figure 4: Supply Curves
• Plant types determined based on long-term
commercial scale feasibility
• Each plant type has unique characteristics (size,
output, cost, etc.) that interact with model
constraints differently
• Renewable outputs vary with strength of resource
• Wind and solar power have outputs that vary as a
function of time while the other four provide
baseload outputs (Figure 4)
15%
10%
5%
11PM
9PM
7PM
5PM
3PM
0%
EESOM divides the nation into ~ 92,000
squares, 10 miles X 10 miles (100 sqmi). Each
square reflects values of:
• Solar Irradiance (Strength of Suns Rays)
• Wind Power Class (Measure of Wind Speed)
• Temperature at 6.5km Depth
• Federal Protection Status
• Population Density
Figure 5: Solar Irradiance
with Example Layers Cutout
Figure 6: Wind Power Class
WIND
GEO, NUC,NAT,COAL
Scenario Analysis and Results
EESOM’s output is the lowest cost regionalmakeup of energy supply that meets demand
within the constraint of natural resources. For
each scenario, EESOM determines:
• Number of plants of each type in each region
• Which plants transport energy to which region
• Cost: 5.92 - 9.31 ¢/KWh
• Capacity: 1.65 MW
• Output: 6.8 - 3.6 GWh/yr
• Area: 84.8 acres
Single turbine; 50m height
1PM
• Cost: 17.34 - 33.52 ¢/KWh
• Capacity: 4.6 - 2.0 MW
• Output: 40.3 - 17.5 KWh/yr
• Area: 20 acres
Dual Flash Hot-Dry Rock; 6.5km
Well Depth; 2 Wells
Sunnier
Wind
While coal, natural gas, and uranium can all
be transported, sun, wind, and subterranean
heat are fixed (Figures 5-7). The location and
intensity of these resources determines
where renewable plants should be built. Land
availability constrains all plant types. Federal
lands (Figure 7) and population density
(Figure 9) limit construction of new plants in
certain areas.
Figure 8: Federal Lands
Scenario 1: Current demand, no cap, no
nuclear limit, no investments
5.9%
6.59%
11.9 %
11.9%
Scenario 2: Double demand, cap at sustainable
emissions, no nuclear plants, no investments
19.8%
17.6 %
24.9 %
25.7%
11.0%
29.7%
22.0%
Figure 7: Temperature at 6.5km
Fed Land
Free Land
Figure 9: Population Density
Higher Temps
Solar
Geothermal
Natural Resources
More Dense
• Cost: 6.32-9.66 ¢/KWh
• Capacity: 560 MW
• Output: 2.6 GWh/yr
• Area: 750 acres
2065 MM tonnes CO2/yr; IGCC;
No Carbon Capture
Windier
• Cost: 6.41-8.16 ¢/KWh
• Capacity: 750 MW
• Output: 3.8 GWh/yr
• Area: 750 acres
3839 MM tonnes CO2/yr; IGCC;
No Carbon Capture
11AM
• Cost: 7.32 - 10.55 ¢/KWh
• Capacity: 2392.90 MW
• Output: 19 GWh/yr
• Area: 6920 acres
Dual PWR Reactor; Safety
Penalty Included
9AM
EESOM’s output is the lowest cost mix of power
plants – including their general location –
necessary to meet demand given the resources
available. The model can be run under a variety of
scenarios, including carbon caps, enabling its use
as a policy analysis and investment assessment
tool. The most relevant finding is that the
domestically available natural sustainable
resources – sun, wind, and subterranean heat –
are sufficient to meet double the current United
States’ energy demand.
Coal
7AM
EESOM utilizes linear optimization to assess
whether an independent and sustainable energy
system is achievable and determines what the
lowest-cost system would look like. The model
minimizes total cost subject to the constraints that
electrical energy demand cannot exceed supply
and resources used cannot exceed resources
available. Issues addressed include: timing of
demand and supply, location of natural resources,
energy transportation costs, and requirements
and capacity of various power generation
technologies.
Nuclear
5AM
Questions such as when and where electrical
energy is needed and how the resources that fuel
its generation should be harnessed, are integral to
the development of a national electrical energy
system. The answers to these questions are
mutually dependent and highly interrelated.
Plant Types and Characteristics
3AM
The United States’ electrical energy sector faces a
set of challenges that could undermine national
security and destabilize the Earth’s ecosystem if
left unaddressed. There is a clear need for a
national energy system that is independent of
foreign inputs and sustainable in nature.
Definitions:
A = Production Region; B = Consumption Region; C = Source type; X A, B,C = # plants; TC = Annual cost/plant;
GC = Output Capacity of Plant C; H A, B= Cost/unit electricity of HVDC line; DB,M , H = Output for Plant C in
Month M at Hour H; EB, M , H = Demand for Region B in Month M at Hour H; WA,B = % Electricity maintained
from Region A to Region B; LA =Land available in region A; FC = Land needed for plant C
% Total Output
Abstract
Electricity usage – the load on the system – varies by hour and
month. This variability is represented in the daily and annual
load curves (Figures 2 and 3). EESOM includes this variation by
dividing demand and supply into 288 slices (24 hours x 12
months).
B 1 C 1
A 1 C 1
2
Variation of Demand in Time
 ( FC  X A, B,C )  LA
 ( ( DC , M , H  WA, B  X A, B,C ))  EB, M , H
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1AM
Department Of Electrical &
Systems Engineering
Demand Constraint
Supply must meet demand
MM MWh/yr
Objective Function
Minimize total cost
Figure 1: Transport Regions with Sample Calculation
Scenario 3: Double demand, no nuclear, no emissions,
geothermal cost reductions via investment
4.57 %
2.28%
13.7%
13.2%
79.5%
Legend
DEMO TIMES
Thursday, April 23, 2009
Times: 9:30, 10:00, 2:00, 2:30
Coal
Prime Solar
Natural Gas
Prime Wind
Nuclear
Moderate Solar
Moderate Wind
Geothermal
• Cost: 7.65¢/kWh ; 4.69% transported ; 4.24 MM tonnes CO2
• Coal serves as low-cost base load resource
• The shape of solar’s output curve makes it useful despite high cost
• Cost of transport forces use of more expensive solar resource in
middle south for transport to eastern regions
• Cost: 7.80¢/kWh ; 2.12% transported ; 1.18 MM tonnes CO2
• With carbon cap, natural gas becomes favorable to coal
• Wind fills base load gap over carbon cap threshold
• Wind resource is abundant
• Cost: 9.01¢/kwh; 65.9% transported ; zero MM tonnes CO2
• With moderate investment, geothermal can serve as cheap,
abundant base load energy source
• Increased reliance on renewables requires high levels of transport
as most natural resources are located in the West