Locational signal for TTC investment by sensitivity calculation

The zonal approach is now broadly adopted by electricity markets worldwide, since it provides the participants with an easily understandable representation of the transmission constraints. The zonal approach and the total transmission capability (TTC) interact in the sense that the higher is the TTC, the lower is the influence of transmission constraints on market results. As a consequence the TTC value is one of the most important issues in a liberalized environment. Its improvement is crucial for the market: it is typically pursued by investments on new branches. The effectiveness of a new line can be measured by evaluating its ability to relieve the transmission constraints that currently limit the TTC: since an exhaustive analysis of this problem would entail an unacceptable computation burden, a new approach based on a sensitivity approach is used to identify possible new lines for planning purposes The related benefits are eventually evaluated by effectively computing the relevant TTC. The effectiveness of this new approach is successfully proved on the Italian transmission network.