and it is assumed that a large part of the power will be utilized in that territory ultimately. The distance that the power would have to be transmitted to reach this market would be approximately 170 miles.

As a basis for determining the cost of transmitting electrical energy to this market, it is assumed that four 220,000-volt circuits would be provided, each capable of delivering 127,000 kilowatts under normal operating conditions with a reasonable factor of safety against instability at times of system disturbances. Each circuit would be capable of carrying up to 146,000 kilowatts under emergency conditions when one of the other circuits is out of service. Synchronous condensers would be provided as part of the terminal substation equipment in the ratio of 0.59 kilovolt-ampere of condenser capacity per kilowatt of delivered power, for regulation of power-factor and voltage.

The cost of the transmission lines including terminal substations and right of way is estimated as follows:

$8,950, 000

340 miles double circuit 220 kilovolt line__ Terminal substations, including synchronous condenser equipment. 5, 458,000 Right of way-

Total----

1, 510, 000

15,918, 000

Estimated annual cost of transmission lines including terminal substations is as follows:

In order to provide reliable and satisfactory service over long distance power transmission circuits, it is generally considered necessary to provide sufficient steam stand-by generating capacity at the terminal end which, together with the overload capacity of the circuits remaining in service, will carry the full load with one of the circuits out of service. On this basis there would be required 70,000 kilowatts of steam stand-by capacity to supplement the delivery of power over the four 220,000-volt circuits contemplated for delivering power to the Puget Sound area at times when one of the four circuits is out of service.

The assumptions used and the estimated annual cost of providing steam stand-by are shown in Table 10 and the annual cost of steam stand-by in dollars per kilowatt of capacity for various prices of fuel-oil and for both public and private developments are shown graphically on drawing No. 222-D-8.

Cost of transmitting energy.-The total cost in mills per kilowatthour for transmitting energy from the Columbia River power plant to the load center for various load factors and prices of fuel oil and for both public and private developments are shown by Tables Nos. 11, 12, and 13 and by graphs on drawings Nos. 222-D-9 and

222-D-10.

C=cost in mills per kilowatt-hour for transmitting energy from the Columbia River power plant to the load center, without steam stand-by.

C=C, except with steam stand-by.

T-annual cost, in dollars, of transmission from the Columbia River power plant to the load center (for the various load factors and for public and private developments as shown in item "b" of Table No. 14).

S=annual cost, in dollars, of steam stand-by (for the corresponding load factors, for public and private developments, and for the various fuel costs, as shown in item "d" of Table No. 14).

K=total energy generated at the Columbia River power plant in millions of kilowatt-hours (for the corresponding load factors as shown in Table No. 14).

TABLE NO. 10

ESTIMATED YEARLY COST OF STEAM STAND-BY, PUBLIC AND PRIVATE DEVELOPMENTS

Assumptions:

Capital cost per kilowatt of installed capacity.

Depreciation (per cent).

Operation and maintenance per kilowatt_

Fuel oil, barrels per kilowatt___.

General expenses, 3 per cent of costs other than oil and taxes.

Return on investment for private development (per cent) -
Taxes on investment for private development (per cent)
Rate of interest for public development (per cent).

Amortization for public development (40-year sinking fund at 4
per cent)____

$77.50

2. 25

$1.75

1.00

3.00

7.00

1.50

4. 75

0.88

Depreciation, return on investment and operation and maintenance. $8.919

$8.919

General expenses.

Fuel oil..

1.00

1.25

. 267 1.50

ANNUAL COST OF STEAM STANDBY
PER KILOWATT OF CAPACITY.

TABLE NO. 11.-Cost of transmitting energy to load center, public and private developments, without steam standby, Columbia Basin project

T-annual cost, in dollars, of transmission from Columbia River to load center.
K=total energy generated at Columbia River in millions of kilowatt-hours.

C=cost in mills per kilowatt-hour for transmitting energy from Columbia River to load center, without steam standby.

TABLE NO. 12.-Cost of transmitting energy to load center, public development, with steam standby, Columbia Basin project

T=annual cost, in dollars, of transmission from Columbia River to load center.
S-annual cost, in dollars, of steam standby.

K= total energy generated at Columbia River in millions of kilowatt-hours.
Cs=cost, in mills per kilowatt-hour, of transmitting energy from Columbia River to load center, with
steam standby.

TABLE NO. 13.-Cost of transmitting energy to load center, private development, with steam stand-by, Columbia Basin project

T-annual cost, in dollars, of transmission from Columbia River to load center.
S-annual cost, in dollars, of steam stand-by.

K total energy generated at Columbia River in millions of kilowatt-hours.

Cs-cost, in mills per kilowatt-hour, of transmitting energy from Columbia River to load center, with steam stand-by.

COST PER KILOWATT-HOUR IN MILLS AT POWER PLANT

0.5

3

EXPLANATION

PUBLIC DEVELOPMENT
PRIVATE DEVELOPMENT

COST OF TRANSMITTING ENERGY FROM

COLUMBIA RIVER DEVELOPMENT TO LOAD CENTER 170 MILES DISTANT WITHOUT STEAM STANDBY