7417

• UCREFRP Catalog Number: 7417
• Author: U.S. Fish and Wildlife Service.
• Title: Flaming Gorge Operations Study December 15, 1988-Preliminary Draft.
• USFW Year: 1988.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

Explanation of Power and Operational Tables
The preceding tables have important and special significance for
power plant operations. Many of the tables are parameter/
function tables which occur in pairs, and define a relation
between a function value and a (variable) parameter value. For
example, reservoir elevation as a function of the reservoir
content is given in a parameter/function table. These tables do
not require twelve entries, but the relationship they define must
be valid for the entire year. HYDROSS performs linear
interpolation to derive a function value for a given parameter
value.
The basic equation for power plants is:
Energy = Constant x Discharge x Head x Efficiency
or
E_ .0010241 x F x H x Y
where
E = generation, in megawatt hours
F = flow, in acre-feet/month
H = head, in feet
Y = plant efficiency, as a fraction
and
H = is reservoir surface elevation minus tailwater
elevation
All of the components are either constant or functions of the
flow, directly or indirectly. Where there is a power requirement,
HYDROSS sets up and solves a partial differential equation to
determine the flow that would produce the required energy. This
is returned to the calling routine as either a requirement for
more water (if positive), or water available for storage or other
purposes (if negative).
1. Power Target
Average power targets were derived from historic operations from
1967 to 1983. A power requirement is similar to an instream flow
requirement, but in.this case the monthly table gives the power
required. The flow required is calculated (by HYDROSS) from the
reservoir content and the head and efficiency data. All reservoir
releases are assumed to go through the power plant, so natural
water will workas well as project water in satisfying the demand.