The Appellate Tribunal for Electricity (APTEL), an India-based statutory appellate body for power sector disputes, has upheld the solar tariff order challenged under Appeal No. 54 of 2020. The solar tariff has been approved by the Tamil Nadu Electricity Regulatory Commission (TENERC) through a competitive bidding process. The appellant had sought tariff revision, stating that capital and operational costs had increased after bid submission. According to the tribunal, the applicable regulatory framework governs competitively discovered tariffs and restricts post-award modifications. As per the record examined, the tariff of INR 4.43 per kWh had emerged from competitive bidding. The tribunal held that such tariffs are binding unless regulations expressly allow revision under specified circumstances. It further stated that post-bid changes in cost assumptions were not sufficient grounds for tariff modification. Based on these findings, the appeal was dismissed, and the TNERC solar tariff order was upheld unchanged.