Plant

Table I-1. Duke Power Company Generating Facilities

These old steam plants have a heat rate that averages 10,676 Btu/kWhr. Year shown is first year of operation and does not reflect subsequent provements, such as installation of gas turbines.

CUpon completion.

A special case, since gas turbine is located outside the DPC district.

respectively.

The capacity of the system with and without these units is compared with the peak loads forecast by the company for the years 1971 to 1974 in Figure 1-3. Without the Oconee capability, the 1973 generating and purchase resources of the applicant would be about 450 megawatts short of its anticipated load for that year. With Units 1, 2, and 3 in operation the reserve capacity would be about 25%.

The amount of reserve capacity that should be provided in a system depends upon the total system capacity, the size and condition of the individual units, and the sharing and transfer arrangements with other utilities. The Duke Power Company was part of the old CARVA pool, which also included the Virginia Electric and Power Company, the Carolina Power and Light Company, and the South Carolina Electric and Gas Company. With the addition of two new members, the Southeastern Power Administration and the South Carolina Public Service Authority, the expanded pool is called the Virginia-Carolinas Reliability Group, a member of the newly organized Virginia-Carolinas Reliability Council. The compounded annual growth rate of this power pool is reported by the Federal Power Commission to be 8.3%.(2) Additions to the installed capacity by members of the CARVA pool will provide a reserve margin of 1,941 megawatts (about 8.8% reserve capacity) if the units are not counted and 4,600 megawatts (20.8% reserve) if the units are included. (The new members are planning additions to the installed capacity of only about 248 megawatts between 1970 and 1973; therefore the reserve margin of the new group will be similar to that of the old CARVA pool.)

These planned reserve capacities may be compared with those which have been planned and justified for other areas. The northeastern United States, for example, is working toward an average reserve capacity of 15 to 20%.

Reserve generating capacity helps to provide assurance against unexpected outages. In addition to the increased reliability, a further advantage of ample new generating capacity is that cutbacks can be made in the operation of old, less-efficient thermal power stations which consume relatively more fuel per generated kilowatt and thus emit greater amounts of pollutants to the environment. All the steam plants shown in Table I-1 are in operation at the present time even though three are more than 40 years old and four others are more than 30 years old.*

*

The applicant plans to retire about 79 megawatts in old units in 1973 (possibly the Tiger, Buzzards, Roost, and Greenwood plants) when the Oconee units are completed.

**

YEAR

THE CAPACITY WITHOUT OCONEE IN THE YEAR 1973 SHOWS A
DECREASE BECAUSE A CONTRACT TO PURCHASE ABOUT 58 MW
OF POWER FROM OUTSIDE WILL BE REDUCED TO ABOUT 40 MW.
INCLUDES 305 MW (e) OF JOCASSEE CAPACITY.

NOTE: The peak load points on the above graph are the

projected maximum demand values during the winter
at the end of the year indicated. Thus, for example,
the peak load forecast indicated for "1972" is the
projected peak load during the winter 1972-73. (See
also Table X-1 on page 103.)

B. SITE SELECTION

The Station is in Oconee County, near the western boundary of the applicant's system, in northwestern South Carolina near the North CarolinaSouth Carolina border. The site is 8 miles northeast of Seneca and about 25 miles west of Greenville, South Carolina.

One of the primary reasons for selecting the general location of the Station was to allow shorter transmission of power to the rapidly growing industrial and domestic load in the western portion of the applicant's service area. Another was the potential for a good supply of cocling water for the plant. A source of cool condensing water provides better thermal efficiencies and lower plant capital costs than if cooling towers are used. Not only were the existing streams and terrain in the vicinity of the site suited to the construction of a reservoir from which cool water could be drawn, but also a hydroelectric turbine could be installed at the dam to provide peaking capacity. Further, a pumped-storage facility could be constructed upstream from the reservoir to provide additional peaking capability. The applicant examined possible arrangements and determined that there were important economic advantages to the multiple-purpose impoundment of the water. A secondary consideration was that the lakes would offer recreational benefits and enhance the area for residential use.

The Keowee hydroelectric station has an installed capacity of 140 megawatts, but the limited flow of water into the reservoir will normally allow generation at this rate only about 5% of the time (5% plant factor). The Jocassee hydroelectric station, with less flow but greater head, will have an installed capacity of 305 megawatts by 1974 and 610 megawatts by 1978, with sufficient water for 14% plant factor at the 305-megawatt rating. The Station will contain three units rated at 886 megawatts each, giving a total generating capacity of more 2658 megawatts at a plant factor of 80 to 90%, or better. Although the capacity of the hydroelectric stations to help meet peak demands is important, it is evident that the total electrical production by the nuclear station overshadows that of the two hydroelectric facilities and that the chief function of the lakes is to furnish an assured supply of cool water for the turbine condensers of the nuclear plants.