PCWA MFP Operations Model

All Models are WrongBut

Some Models are Useful

What is a Model?A Simulation Model is a mathematical representation of a physical system that includes:

RiversReservoirsConveyance and Release Facilities

Tunnels, Penstocks & Powerhouses,

Streamflow release valves

Operating Rules, Licenses and Agreements

What is a Model?

The Model routes water (Input Hydrology) through the System (mathematical representation of the physical world) according to Rules

What is a Model?

A model chooses how water is routed through the system in order to meet certain criteria and goals.

A model allows us to measure the impact that changes to the input set will have on the output set.

What are the Rules?

Rules are inputs to the Model

Rules represent decisions made by the operators

Rules fix operating parameters that can vary from run to run

Examples of Rules

Instream flow requirements

Storage level requirements and targets

Use of discretionary water supplies

Meet Consumptive Demands

Generate Power

Provide Recreation

Other Model Inputs

Flow (Hydrology) - PCWA believes that it has a reasonably accurate record of Project flows since the project began operation in 1968

For each different set of inputs, we intend to generate output using the same identical set of historic hydrology

Other Model Inputs

Fixed Criteria - project parameters that cannot be changed without physical alteration of the Project. Fixed Criteria include:

Tunnels and Turbine capacities

Outlet capacities

Elevations

Other Model Inputs

Water Supply Demands - special class of Rules

Consumptive demands at Folsom Reservoir

Consumptive demands at Auburn Pump Station

Environmental Demands (Water Forum Agreement)

Model Outputs

Tables to verify that the Rules are met

Rules guide the operation of the model, but may not be met 100% of the time. For example, minimum instream releases will not be met if a reservoir runs dry. Having the flexibility to violate rules helps provide information.

Model Outputs

Reservoir Level Trace

Identify excursions from “preferred” operation - too high (spills and loss of generation) or too low (risk of failure to meet consumptive demand)

Power Generation

Benchmark and Baseline

A Benchmark Run is used to verify that the model reasonably represents actual historic operations

The Baseline Run is the run against which all Alternative Model Runs are compared to determine the impacts of proposed conditions on the MFP operation

Benchmark and Baseline

PCWA proposes that the difference between the Benchmark and the Baseline Runs is that the Benchmark Run uses historic consumptive water demands and the Baseline Run uses buildout consumptive water demands

Using the Model

Model

Consumptive Demands

Hydrology

Operating Rules

Fixed Criteria

Verification Tables

Reservoir Levels

Input

Output

Baseline Study

Generation

Model

Consumptive Demands

Hydrology

Operating Rules (Changes)

Fixed Criteria

Verification Tables

Reservoir Levels

Input

OutputGeneration

Alternative Study

Assess Impacts

Assess Impact

s

Compare

Outside Model

Inside Model

Assessing Impacts

The Model Does Not assess environmental impacts

The model only provides comparative information on water supply and power generation for Alt Model Runs

Assessment of the full impacts of any Model Run is done by people

Assessing Impacts

An analysis of the benefits and costs of each alternative may be viewed differently by each person

To develop alternatives based upon environmental parameters requires completion of the 1st year of field studies. March 2009.

Alternative Model Runs

The desire to create a given environmental condition leads stakeholders to suggest changes to the rules

The resulting model run shows the impact of the rule change on water supply and power generation

Where are we now?

The Model is operational

Benchmark input set has been assembled for testing

A draft users manual has been prepared

What do we do until 2009?

Verification

Education

Development (betterments, hourly)

Investigate physical limitations

Find our sideboards: Dry year issues, Ralston Afterbay flexibility

How do we get there?

Process: We need good process around our group understanding of how Modeling Alternatives are developed, run and assessed