SUNRISE POWER LINK A

Document Sample
SUNRISE POWER LINK A Powered By Docstoc
					                    SUNRISE POWER LINK A.06-08-010
                     SDG&E’S 3/26/08 RESPONSES TO
                       MGRA DATA REQUEST #7



MGRA-52   Is the map attached to the SDG&E response to MGRA Data Request #6,
          titled “SPRL Wind Speed Map.pdf” a correct and complete depiction of the
          maximum wind gust speeds used for calculation of wind load during the
          design of the Sunrise Powerlink transmission project and its construction
          cost estimates?

SDG&E Response

          The wind speed map provided in response to MGRA data request #6 has
          been revised, and submitted to MGRA on March 19, 2008. The values
          provided on the map for the two transmission line segments of the Sunrise
          Powerlink project, Penasquitos to Santa Maria Valley, and Santa Maria
          Valley to Central Substation site, have been revised to match the values
          currently being used for transmission structure design for maximum wind
          gust. These wind speed requirements shown on the revised wind map are
          included in the Sunrise Powerlink cost estimates provided in our testimony.
                    SUNRISE POWER LINK A.06-08-010
                     SDG&E’S 3/26/08 RESPONSES TO
                       MGRA DATA REQUEST #7


MGRA-53   There are apparent contradictions between the map in “SPRL Wind Speed
          Map.pdf” and the calculation methods described in the answer to this data
          request. A detailed description of these contradictions is provided in the
          MGRA Phase 2 direct testimony on pp.64-66 and also in Appendix 2G, pp.
          13-14. Which of these – the values derived from the provided map or the
          values that would be derived from the calculation method in the Data
          Request response – represents a correct description of how the maximum
          design wind gust values were obtained for the design of the Sunrise
          Powerlink project and its construction cost estimates?

SDG&E Response


           The wind map has been revised to match the calculation as described in
           response to MGRA-52 above.
                    SUNRISE POWER LINK A.06-08-010
                     SDG&E’S 3/26/08 RESPONSES TO
                       MGRA DATA REQUEST #7


MGRA-54   How does SDG&E explain the apparent contradictions noted in MGRA-53
          and described in the MGRA testimony?

SDG&E Response


           The wind map has been revised to match the calculation as described in
           response to MGRA-52 above, and therefore there is no longer a
           contradiction.
                       SUNRISE POWER LINK A.06-08-010
                        SDG&E’S 3/26/08 RESPONSES TO
                          MGRA DATA REQUEST #7


MGRA-55     What is the current estimated total construction cost for the Sunrise
            Powerlink project, assuming the proposed route?

SDG&E Response


Please refer to Tables 3.1 and 3.2 in SDG&E’s March 12, 2008 Direct Testimony.
                          SUNRISE POWER LINK A.06-08-010
                           SDG&E’S 3/26/08 RESPONSES TO
                             MGRA DATA REQUEST #7


MGRA-56        What were the construction costs calculated for the Sunrise Powerlink, in
               dollars per mile, averaged, for the following segments of transmission line
               (as described in SDG&E’s answer to MGRA-49):
               Del Mar – Ramona: “From the Penasquitos substation to an elevation of
               about 2,200 ft MSL just south of the Santa Maria Valley (about 22 miles
               inland)”1
               Ramona – E. Ramona: “The Santa Maria Valley area southeast and east of
               Ramona (about 22-28 miles inland)”
               E. Ramona – Grapevine: “From the east edge of the Santa Maria Valley to
               a few km southeast of Ranchita (about 28-34 miles inland).
               Grapevine – Desert: “The short stretch of corridor (about 6 miles long)
               through the Grapevine Canyon mountain pass, north of Grapevine
               Mountain and the Volcan Mountains, and about 6 miles southeast of
               Ranchita, California. Wind direction should be parallel to the pass
               orientation, from either the west-northwest or the east-southeast (about 34-
               40 miles inland).”

SDG&E Response


                 Average cost per mile estimates can be obtained for the various segments
                 provided within the Confidential Attachment 3-1 of SDG&E’s Phase II
                 testimony. Cost per mile estimates specific to the areas requested are not
                 readily available.




1
    SDG&E Response to MGRA Data Request #6; MGRA-49.
                     SUNRISE POWER LINK A.06-08-010
                      SDG&E’S 3/26/08 RESPONSES TO
                        MGRA DATA REQUEST #7


  MGRA-57 What are the construction costs, in dollars per mile, typical, for
          transmission lines engineered to the following wind gust standards:
          a) 56 mph (for 230 kV)
          b) 68 mph (for 230 kV and 500 kV)
          c) 73 mph (for 230 kV)
          d) 88 mph (for 230 kV)
          e) 92 mph (for 230 kV)
          f) 146 mph (for 230 kV and 500 kV)
          Note: each of these values appears in either the “SPRL Wind Speed
          Map.pdf” map or in calculations based upon the method recommended by
          SDG&E. Assume two circuits for the 230 kV lines, as per the SPL design.

SDG&E Response

            Similar to the proposed Sunrise Powerlink project the typical 230 kV
            transmission cost per mile would range between $3 and $4 million/ mile,
            and the cost per mile for the 500 kV portion would range between $2 and
            $3 million/mile. The project cost and design are based on wind gust
            speeds as shown on the revised wind map provided in the revised response
            to MGRA data request no. 6. These revised maximum wind gust values,
            provided in the revision to MGRA data request no. 6, encompass the wind
            speeds described above (except for cases e and f for 230 kV) and,
            therefore there would be no increase in these costs. SDG&E has
            determined that cases e and f are not required for the 230 kV transmission
            structures on Sunrise Powerlink project.
                       SUNRISE POWER LINK A.06-08-010
                        SDG&E’S 3/26/08 RESPONSES TO
                          MGRA DATA REQUEST #7


MGRA – 58 For each of the engineering countermeasures listed in the response to
          question MGRA-51, please list
          a) The wind gust speed range in which that countermeasure would be
          considered appropriate; and
          b) The incremental cost increase per mile of transmission line that applying
          that particular countermeasure would incur.

SDG&E Response


              The engineering countermeasures provided in response to question
              MGRA-51 are not based on incremental wind speeds. They are simply a
              listing of engineering design options that can be used to strengthen
              transmission structures. Therefore it is not appropriate to assign wind gust
              speeds to each of these countermeasures. Similarly individual incremental
              costs cannot be assigned to these countermeasures.

				
DOCUMENT INFO