# SN-03 BPA Data Response

**Request No.:** WA/BPA:008

**Request:** Witnesses: N/A

Exhibit: SN-03-E-BPA-01

Page(s) Page 4-6, lines 12-16

Please discuss why the WECC 10-Year Coordination Plan Summary
(2000-2009) load forecast was used when the WECC 10-Year Coordination
Plan Summary (2002-2011) is available. Please also discuss why this
forecast was used instead of the WECC 10-Year Coordination Plan Summary
(2001-2010), which was used for the average annual growth rates on page
4-8.

**Response:**

At the time the study was being developed, the WECC 10-Year Coordination
Plan Summary (2000-2010) and the WECC 10-Year Coordination Plan Summary
(2001-2010) were the best information available.

April 10, 2003

# SN-03 BPA Data Response

**Request No.:** WA/BPA:009

**Request:** Witnesses: N/A

Exhibit: SN-03-E-BPA-01

Page(s) Page 4-8, lines 1-6

Please discuss why the WECC 10-Year Coordination Plan Summary
(2001-2010) load forecast was used when the WECC 10-Year Coordination
Plan Summary (2002-2011) is available.

**Response:**

At the time the study was being developed, the WECC 10-Year Coordination
Plan Summary (2001-2010) was the best information available.

April 10, 2003

# SN-03 BPA Data Response

**Request No.:** WA/BPA:010

**Request:** Witnesses: N/A

Exhibit: SN-03-E-BPA-01

Page(s) Page 4-14, Table 4-8

Please explain why the mean and median prices for the light load hours
are greater than the prices in the heavy load hours in the month of
September.

**Response:**

AURORA uses shaping factors to shape hydroelectric generation into heavy
load hours and light load hours. The higher these factors are set, the
more generation will be shaped into heavy load hours. If these factors
are set too high, hydroelectric generation will be shaped into heavy
load hours, thus displacing other generation. The corresponding amount
of hydroelectric generation to be used in light load hours is also
reduced. If too much hydroelectric generation gets shaped into the heavy
load hours, other resources may be called on in light load hours to meet
load due to the decreased hydroelectric generation levels. The variable
cost of these resources in light load hours may be higher than the
variable cost of the resources in heavy load hours when more
hydroelectric generation is present. Thus, the resulting price for heavy
load hours may be less than that of light load hours. BPA staff proposes
to change these factors for the final proposal to eliminate this result.

April 10, 2003

# SN-03 BPA Data Response

**Request No.:** WA/BPA:011

**Request:** Witnesses: N/A

Exhibit: SN-03-E-BPA-01

Page(s) Page 4-15, Table 4-9

Please update Table 4-9 to reflect the most current water volume
forecast from the Northwest River Forecast Center.

**Response:**

BPA staff propose to update the table for the final proposal. At that
time, BPA staff propose to incorporate the best information about
hydroelectric supplies in the study.

April 10, 2003

# SN-03 BPA Data Response

**Request No.:** WA/BPA:012

**Request:** Witnesses: N/A

Exhibit: SN-03-E-BPA-01

Page(s) Page 4-15, Table 4-9

Please provide a spreadsheet that shows the relationship between average
annual runoff, either in terms of percent of normal or MAF, and annual
energy output on the FCRPS assuming a normal progression of seasonal
runoff.

**Response:**

> For each fiscal year, BPA is providing a spreadsheet (WA-BPA-012a)
> that reflects monthly and annual FCRPS average hydro generation for
> each of the 50 water years along with the associated Oct-Sep average
> annual runoff measured at The Dalles. For FY03, BPA has provided a
> 9-month average instead of the annual average because the studies were
> initialized to January.
>
> Please refer any questions about this data response to the Loads and
> Resources panel.

April 10, 2003