Quantifying the long-term benefits of interruptible load scheme for distribution network investment

This paper seeks to measure the long-term benefits brought by the interruptible load scheme (ILS) to network utilities and customers. Normally, the ILS is adopted as necessary to reduce system peak demand. By contrast, this paper states that if the scheme is adopted during network contingencies that drive future reinforcement, great benefits might be obtained. It assumes that the long-term benefits incurred from introducing the scheme needs to be investigated and long-term use-of-system pricing is qualified for this purpose. In order to encourage customers to participate in the scheme, the derived charges can work as economic incentives. Hence, the long-run increment cost (LRIC) pricing for interruptible loads is reported, which is able to truly recognize the impact of ILS on network investment in long-term. The benefits from introducing the scheme are evaluated in terms of deferral in present value of future reinforcement of network investment and the reduction in nodal use-of-system charges. The concept is demonstrated in a practical Extra-high voltage (EHV) distribution network, indicating its effectiveness.