dsd-int 2014 - delft-fews users meeting - operating the federal columbia river power system in a...

B O N N E V I L L E P O W E R A D M I N I S T R A T I O N

Operating the Federal Columbia River

Power System in a World of Uncertainty

Christopher R Allen

Short Term Planning and Operations

Operations Research Analyst


Agency Background

Bonneville Power Administration (BPA) is a federal nonprofit agency based in the Pacific Northwest region of the United States.

BPA was established in the 1932 as an agency within the U.S Department of Energy. The agency is largely responsible for marketing wholesale power from:

• 31 multipurpose hydro electric dams; 22 GW

• 1 nuclear plant; 1.1 GW

• several smaller sources

BPA also operates and maintains about three-fourths of the high-voltage transmission in the region


Basin 614,000 km2 (approximately the size of France)


Grand Coulee Dam, 6.4 GW (est 1942)

Irrigation Facility; 708 m3/s


Bonneville Dam, 1.08 GW (est 1937)


Multipurpose dams are operate by the U.S Army Corps of Engineers and U.S Bureau of Reclamation:

• Flood Protection

• Environmental (Endangered Species & Clean Water Acts)

• Navigation

• Irrigation

• Recreation

• Variable resource integration (wind resources)

• Reliable electric power

Operations mission is to maintain high level of benefits while minimizing and mitigating the harm to fish and wildlife in the face of growing uncertainty and decreasing operational flexibility

Federal Columbia River Power System


Key Regional Stakeholders

• States of Oregon, Washington, Idaho and Montana

• Canada

• Tribal Nations

• Preference Power Customers

• Private resource owners (hydro electric)

• Recreator(s)

• Irrigators

• National Oceanic and Atmospheric Administration

Planning and coordinating the operation of the FCRPS is very complex and involves many different competing interests.




Annual Water Year (October – September) – Average runoff 164 km3 (Range: 98-241 km3) or 5200 m3/s on

average as measured at The Dalles

– Spring runoff (April – June)

Federal storage about 37 km3 (1/4 annual runoff) – Colorado and Missouri basins can store x2-x3 their annual runoff

Geographical variability between snowpack sources – Significant influence on spring runoff shape (timing & magnitude)

– Minimizing spill at the confluence of Columbia and Snake River systems is challenging during peak runoff period


October-December

Store water through October in preparation for fisheries operation. Release flows to support fisheries objectives.

January-April

Draft system for flood control while maintaining fisheries spawning habitat elevations. (Starting in April; spilling to support downstream migration of juvenile fish. Energy loss 1500 aMW)

May – June

Refill the system on the Spring freshet while meeting flow objectives for downstream fish migration.

July – August

Draft the system to augment flows supporting the downstream migration of juvenile fish.

September – October

Operate the system to prepare for Fall fisheries operations at

Grand Coulee, Vernita Bar, and downstream of Bonneville.

FCRPS Annual Operations Cycle


Power production is driven by the need to manage water to

meet objectives, which can often conflict, in the most

economic way possible while meeting load obligations.

– Long-term and short-term energy markets are used to buy and sell

energy necessary to meet load obligations and to shape energy

production to meet operational objectives

– There must be sufficient flexibility in our resources and in the

marketplace to handle uncertainties

Capacity (flexibility) is set transmission reserve obligations: – 1600 MW Incremental (INC) reserves: capacity that is reserved

for when wind generation falls below the schedule or load increases within an hour

– 1100 MW Decremental (DEC) reserves: generation above minimum that is reserved for when wind generation is above the schedule or load drops within an hour



Uncertainty Today and Tomorrow

Uncertainty sources in daily operation – Meteorological and model related:

• Meteorological (temperature, precipitation) incorporated in the streamflow and load forecasts

• Streamflow related to BPA’s hydrological models to forecast annual runoff and day-to-day short-term forecasts

• Loads related to BPA’s load models

– Power system • Ancillary Services: balancing and contingency deployments

• Resource Availability: unit outages and wind resource generation

• Power Contracts: dependent upon uncertain power market prices

• Market Liquidity: sufficient depth to manage objectives

– Non-federal reservoir operations: Private Utilities and Canada

– Operational constraints: flood control, environmental, etc…

Increasing environmental requirements will likely reduce FCRPS capability and operational flexibility in the future


Lower Snake deterministic streamflow forecast Variability in deterministic forecasts can have tremendous operational consequences. (Inflow forecasts ranged between 2290 m3/s and 5950 m3/s in a 5-day span.)

Lower Granite Inflow Forecasts June 2 -9, 2010

50

70

90

110

130

150

170

190

210

230

6/2 6/3 6/4 6/5 6/6 6/7 6/8 6/9 6/10 6/11 6/12 6/13

KC

FS

F2 F3 F4 F7


Uncertainty in Reserves Deployment


Responding to future uncertainty

Develop measures of Operational Flexibility – The ability of resources to respond to changing conditions

More operational constraints = less operational flexibility

Develop strategies to quantify sources of uncertainty -Meteo, streamflow, loads forecasts

-Reserve obligations/deployments

-Resource availability

Explore market opportunities – The ability of the marketplace to supply sufficient amounts and

types of energy and capacity products. (New flexible resources or innovative market solutions like Energy Imbalance Market)

BPA Technology and Innovation projects aim to develop strategies to assess sources of uncertainty and measures of operational flexibility


Improve Short-term Decision Support Tools

Enhancement of the production system – Flexible data-model integration platform based on Delft-FEWS

– Replacement of the current deterministic optimization model

– Optimization models: RTC-Tools (Deltares)

Investments in Technology and Innovation projects:

1)Short-Term Hydropower Production and Marketing Optimization (HyProM) (Deltares & Fraunhofer IOSB-AST)

2)Development of a State-of-the-Art Computational Framework and Platform for the Optimal Control of Multireservoir Systems Under Uncertainty

3)Computationally Efficient, Flexible, Short-Term Hydropower Optimization and Uncertainty Analysis for the BPA System

Flexible data-model integration platform will enable BPA to more easily integrate advancements of TI projects.


TIP 259: Short-Term Hydropower Production and

Marketing Optimization (HyProM)

– Probabilistic short-term optimization is a main research topic and enables a better consideration of forecast uncertainty from multiple sources (meteo, streamflow, load)

– Integrated short-term management of hydropower production and marketing; 21 day forecast horizon

– Evolution from deterministic to stochastic optimization techniques

– Development of tools for integrated management of scenarios of streamflow, wind generation and load and meteo-related uncertainty


TIP 259: Short-Term Hydropower Production and

Marketing Optimization (HyProM)

common

control on both

branches

time

stream flow,

load etc.

forecast time

cold front with

30% probabilitymore stream flow &

wind, less load, low price

probability = 30%

less stream flow & wind,

more load, high price

probability = 70%

not sensitive to

constraints, high

flexibility (green)

sensitive to constraints, low

operational flexibility (red)


Scenario Trees to Model Decision Making under

Uncertainty

Decision Uncertainty Resolution Decision

Once uncertainty is resolved, it is possible to adopt the control

strategy optimal to the remaining scenario !!!

RainRain

No RainNo Rain

t

P

1 2 3 40 t

P

1 2 3 40

t

P

0 1 2 3 4 t

P

0 1 2 3 4disturbance

control

No Rain

Rain

before uncertainty resolution

after uncertainty resolution

t

u

0 1 2 3 4 t

u

0 1 2 3 4


Scenario Trees to Model Decision Making under

Uncertainty

Decision Uncertainty Resolution Decision

Once uncertainty is resolved, it is possible to adopt the control

strategy optimal to the remaining scenario !!!

RainRain

No RainNo Rain

t

P

1 2 3 40 t

P

1 2 3 40

t

P

0 1 2 3 4 t

P

0 1 2 3 4disturbance

control

No Rain

Rain

before uncertainty resolution

after uncertainty resolution

t

u

0 1 2 3 4 t

u

0 1 2 3 4

Branching Point

A tree specifies when uncertainty is resolved

Control Tree

t

u

0 1 2 3 4 t

u

0 1 2 3 4

Rain

No RainNo Rain


Meteo Versus Model Uncertainty (Orofino, Snake Basin)

• Largest uncertainty of prob. forecast during snow melt

• Overestimation of model uncertainty because of missing (manual) data assimilation in hindcast experiment


Streamflow Versus Load Uncertainty (Snake Basin)

• Streamflow uncertainty is significantly larger than the load uncertainty in the period January – June

• Load uncertainty is larger in the winter half, but relatively small


Forecast Convergence Score (FCS)

• Measures the change from one forecast to another

• Probabilistic forecast is more stable and should lead to more stable decisions


From Ensemble to Scenario Tree

similar ensemble members

and their probabilities get

aggregated (dedicated FEWS

display is on its way)


Forecast Uncertainty Propagating through the system

forebay elevation

(system state)

total outflow

(control variable)


Conclusions and Outlook

– Probabilistic forecast & stochastic optimization leads to better and more stable decisions compared to the deterministic approach

– Scenario tree based optimization technique translates forecast uncertainty into a distribution of control trajectories and system states; objectives and constraints enable the decision maker to direct the system

Next steps:

– FEWS based production system

– The integration with an energy marketing model is on its way to add another dimension of operational flexibility by approaching the energy market

– R&D (HYPROM) will be delivered in April 2015

dsd-int 2014 - delft-fews users meeting - operating the federal columbia river power system in a...

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