PUB00037

• Year: 1988
• Title: Colorado Joint Planning Study Economic Potential of Pumped Storage
• CWCB Section: Interstate & Federal
• Author: Colorado Water Resources and Power Development Authority
• Description: Assessment of whether pumped storage facilities are economically attractive to Colorado utilities
• Publications - Doc Type: Water Resource Studies

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each generating unit's output for 1986. The heat rates, loading blocks, forced outages,
fuel costs, maintenance schedules, and purchase power schedules of each unit of
each utility were modeled. The benchmark runs were verified by the utilities, and the
model was calibrated for a 20-year study period with a 30-year extension period. In
this way the calibrated model accurately represented the historical generating patterns
for the utilities studied.

The TSC decided to use either a 15- or 20-percent reserve margin depending on each
utility's characteristics. The medium peak load and energy forecasts and escalation
rates were reviewed for reasonableness and consistency of methodology and
assumptions. Each utility was then dispatched on the EGEAS model for the planning
horizon serving its own native load and making sales and purchases as appropriate.
The utilities were modeled to reflect current levels of interconnections and agreements
controlling interutility power flows. An expansion plan was prepared for each utility
using the EGEAS optimization dynamic program option with the exception that the
utility's current "most likely" expansion plan was used to schedule the units. The
EGEAS-optimized expansion plan established a reasonable base case for each utility
to compare against the cases with the pumped storage units.

In addition, the other Colorado utilities were simultaneously dispatched with the
selected primary utility system so that economy energy transfers and reserve sharing
could be accounted for between the systems and all existing generating capacity in
the state would be utilized prior to the addition of new generating capacity. Table 2-4
shows the six modeling scenarios that were completed.

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