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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3.2 Results

The resulting expansion plan is shown in Table 3-1, including the mix of future
generation plants, reserve margins, and purchases and sales on a statewide basis.
The expansion plan is based on the medium load growth forecast. (The expansion
plans for the low and high load growth forecasts are presented in 5.0.)

The first two columns of the expansion plan table show the study period years and the
total existing generation capacity for the Colorado utilities. The next three columns
show the new generating units (coal, combustion turbine, and combined cycle) that
are added under the base case assumptions. The sixth column (labeled "purchases")
is the capacity purchased from Western Area Power Administration, out-of-state
purchases, or power from Qualifying Facilities (QFs). In-state purchases and sales
were not considered since they are offsetting when the statewide totals are
considered. The column labeled "other" represents committed generating units,
retirements, and small hydroelectric plants. The preceding columns are then summed
in the "Total Colorado Capacity" column. The ninth column ("Total Colorado Peak
Load") represents the nOncoincident peak load of the utilities and is compared to the
total capacity in order to compute the percentage reserve margin which appears in the
tenth column, "Reserve Margin." The noncoincident peak loads were used since each
utility plans to meet its individual peak and not a coincidental statewide peak. The
right-hand columns labeled "Potential Purchases and Sales" show the capacity
(peaking and base load) needed by certain individual utilities, that could potentially be
purchased from another utility in the state starting in the year indicated and lasting
through the study period. Of course, the purchase would be contingent upon
successful price negotiations between the willing buyer and seller.

As shown on Table 3-1 for the medium load growth assumption, there is sufficient
capaCity in the state until 2001, after which new units will have to be added to meet the
increases in demand. This assumes the four planned units will be placed in service in
1990,1991,1996, and 1997. A total of about 1,382 MW of additional generating
capacity is required over the study period (1988-2007). More than half of the required
capacity (785 MW) is base load capacity, while 597 MW is peaking and combined
cycle capacity. This capacity was added to the 196 MW (180 net MW, there are 16 MW
of planned retirements) that was already planned by the utilities. This mix is important

3-2