Analysis of supply costs in buses of the National Interconnected System of Paraguay under uncertainty

This paper proposes a method for addressing the transmission expansion plan by means of analyzing the system congestion. For this purpose, the marginal supply cost in each bus of the system is used as the indicator of congestion, obtained through computing an Optimal Power Flow AC (OPF AC). The applicability of the proposed method is verified by adopting the National Interconnected System of Paraguay as a case study. Likewise, it is considered that demand develops an uncertain growth, thus such growth is described by means of the Brownian Motion stochastic process and Monte Carlo realizations. The long-term system expansion is assumed to follow the Plan of Infrastructure of the National Electricity Administration (ANDE) of Paraguay. In addition, new investments are incorporated in order to assess the impact on the prevailing congestion level of the system. Finally, a stochastic discounted cash flow is applied in order to value if the tariff perceived by ANDE is sufficient for covering the capital costs of future investments, given the resulting congestion levels.