Transmission Wheeling Charges Study for the Southern African Power Pool Phase 2

Client: Department for International Development, UK.

Project Manager: Peter Beard

PPA was appointed by DfID, with Frontier Economics as a sub-consultant, to carry out the second phase of the Wheeling Charges study for the Southern African Power Pool. The distance-related (MW-km) model developed in Phase 1 was automated and made suitable for interfacing directly the PSS/E transmission planning software. A matrix of wheeling charges (tariffs) and increment losses was developed for all the potential wheeling transactions. Training was provided to the SAPP counterpart team in the operation and updating of the wheeling model.

Description of Services Provided:

PPA staff were responsible for the development of the wheeling charges model in MS-Excel, using Visual Basic programming. The team worked closely with the SAPP counterpart team who carried out the PSS/E studies to model the wheeling transactions under the supervision of PPA. PPA developed a seamless interface between the PSS/E- DCCC output file and the wheeling charges model input file. This was achieved by developing a system of coding relating the transmission equipment and corresponding cost files. PPA carried out extensive QA/QC checks on the model and it was then used in calculating a matrix of wheeling charges / tariffs for all potential transactions between the SAPP Operating Members. A matrix of incremental losses corresponding to the wheeling transactions was also calculated. The weighted average cost of capital was calculated for the SAPP member countries for use in the wheeling charges model. PPA staff conducted a workshop on the SAPP wheeling model and made a presentation of the results of the study to the bi-annual SAPP meeting held in August 2001, in Lesotho.