potential climate change impacts to the nw hydroelectric system nw hydroelectric association...
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Potential Climate Change Impacts to the NW Hydroelectric System
NW Hydroelectric Association ConferenceFebruary 20, 2013
2
Outline• Global Circulation Model
Output
• Assessing impacts to the hydroelectric system
• Mitigation Actions?
February 20, 2013
3
Global Climate Models• Climate Impacts Group – University
of Washington• Up to 20 climate models• At least 2 GHG scenarios • Downscaled for the NW
• Two key outputs for our analysis: Temperature changes Altered natural river flows
Can also model climate studies from other groups if data is available
February 20, 2013
River Management Joint Operating Committee
(RMJOC)
Two key functions:1. Vet natural flow and temperature data2. Provide additional data required to run hydro
studies• Flood control elevations• Hydro operating rule curves
Precipitation Changes (~2030)
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Source:Climate and Hydrology Datasets for Use in the RMJOC Agencies’ Longer-Term Planning Studies: Part I - Future Climate and Hydrology Datasets
No significant overall change
Temperature Changes (~2030)
6
Source:Climate and Hydrology Datasets for Use in the RMJOC Agencies’ Longer-Term Planning Studies: Part I - Future Climate and Hydrology Datasets
Expected higher temperatures
7February 20, 2013
Source:Climate and Hydrology Datasets for Use in the RMJOC Agencies’ Longer-Term Planning Studies: Part I - Future Climate and Hydrology Datasets
Precipitation can be higher or lower
Temperature is always higher
Temp and Precipitation
Changes
2020's Natural Flow at TDA: 70 year avg.
-
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
450,000
500,000
550,000
600,000O
ct
No
v
De
c
Jan
Fe
b
Ma
r
Ap
r I
Ap
r II
Ma
y
Jun
e
July
Au
g I
Au
g II
Se
p
Qn
(cf
s)
'
Study 21: Base Study 23: MW/D Study 24: LW/W Study 25: MC
Study 26: C Study 27: MW/W Study 28: LW/D
8
Source:Climate and Hydrology Datasets for Use in the RMJOC Agencies’ Longer-Term Planning Studies: Part I - Future Climate and Hydrology Datasets
Change in Natural Flows @ The Dalles (~2030)
9February 20, 2013
Oct Nov Dec Jan Feb Mar Apr1-15
Apr16-30
May Jun Jul Aug1-15
Aug16-31
Sep0
100000
200000
300000
400000
500000
600000
700000
800000
900000
Normal Variation in Flows vs. Average FlowsFl
ow (C
FS)
Average Natural Flows in BLACKAverage Climate Adjusted Flows in RED
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CIG Forecast Changes
• Runoff volume and river flowVolume not likely to change
significantlyHigher winter flows, lower summer
flows• Temperature
More likely to increase than decreaseMedian case 2.05 degrees 0F higher by
2030
February 20, 2013
11
Outline• Global Circulation Model
Output
• Assessing impacts to the hydroelectric system
• Dealing with climate uncertainty
February 20, 2013
Temperature Effects on Demand ~2030(For illustration only)
-1500
-1000
-500
0
500
1000
1500
2000
2500
3000
3500S
ep
Oc
t
No
v
De
c
Ja
n
Fe
b
Ma
r
Ap
r
Ma
y
Ju
n
Ju
l
Au
gPe
ak
De
ma
nd
(M
W)
-6
-4
-2
0
2
4
6
8
10
12
14
De
gre
es
(F
)
Demand
Temp
Heating Season
Cooling Season
13
Changes to Regulated Outflow ~2030(For illustration only)
February 20, 2013
Oct
Nov Dec Jan
Feb
Mar
Apr 1
Apr 2
May Jun Jul
Aug
1
Aug
2
Sep
-30000
-20000
-10000
0
10000
20000
30000
40000
50000
Difference in Regulated Outflow at McNary
Flow
(CFS
)
14
Changes to Power Generation ~2030(For illustration only)
February 20, 2013
Oct
Nov Dec Jan
Feb
Mar
Apr 1
Apr 2
May Jun Jul
Aug
1
Aug
2
Sep
-1500
-1000
-500
0
500
1000
1500
2000
Difference in Hydro Generation
Meg
awatt
-Per
iods
Impacts to Power Generation ~2030(For illustration only)
Changes to: February July
Generation + 1,700 MW - 1,000 MW
Demand - 1,000 MW + 3,000 MW
Balance + 2,700 MW - 4,000 MW
16
Outline• Global Circulation Model
Output
• Assessing impacts to the hydroelectric system
• Mitigation Actions?
February 20, 2013
Typical Reservoir Operations
0
900
1800
2700
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Ele
vati
on
Full
Empty
Draft for
Power
Draft for
Flood Control
Refill
Potential Mitigating Actions(My opinion only – not endorsed by the Council)
1. Release more water in summer
2. Coordinate with Canada for additional summer releases
3. Refill in winter with anticipated additional rainfall
4. Develop better forecasting methods for fall and winter flows – the beauty of this approach is that hydro operations will be better regardless of whether we see future warming or cooling
Potential Mitigating Operations
0
900
1800
2700
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Ele
vati
on
Before
After
Full
Empty
Winter Refill Higher
Flood
Control
Late Summer
Draft
Fill by J une
20
Other Issues to Consider
Climate change adjusted streamflows come from one source only
Issue of frequency of extreme events is not well quantified
Current analysis assumes equal likelihood for all streamflows– Should apply weights based on longer
records– Apply different weights for climate studies
February 20, 2013