Unlike non-variable renewable energy (VRE) generators, VRE generators have site-specific, various, and uncertain characteristics that require different approaches for power wheeling cost calculations. The conventional power wheeling method cannot be used to accommodate the variability and site specificity of VRE. This study aims to develop a power wheeling calculation method that accommodates the variability and site specificity of VRE by comparing the postage stamp and MW mile methods in a multi-period optimal power flow simulation. The impact of line contingencies on the total power wheeling cost is also assessed. The simulation uses a modified IEEE 39 bus system as the test network, with three study cases centered on assessing the impacts of variability, site specificity, and line contingency. Based on the simulation, it is understood that the pivotal power wheeling cost is the line used by power wheeling actors, as there are cheaper and more expensive lines. Therefore, the total power wheeling cost is less affected by variability and more affected by the site specificity of VRE. On the other hand, because of the meshed network being employed as the test case, line contingency results in a lower cost for power wheeling actors to use fewer and cheaper lines.
Read full abstract