Modelling and evaluation of interruptible-load programmes in electricity markets

Achieving higher system reliability using market-based approaches is a contemporary issue that has been attracting a great deal of attention in the emerging deregulated electricity-market structure. The paper presents a methodology for the modelling and evaluation of interruptible-load programmes to tackle this issue. The interruptible-load programme is formulated as an equivalent price-based generating resource with a random outage effect, and is thus incorporated in a probabilistic production simulation of a system. The interdependence between the electricity spot-market price and the equivalent generating-resource parameters is addressed and solved by an iterative co-ordinating algorithm. The proposed approach is capable of achieving comprehensive evaluations and systematic decision making for the interruptible load programme in electricity-market operation. A numerical-case-study example is presented to illustrate the validity of the method. The results reveal that interruptible-load programmes can serve effectively as a market-based tool to achieve a proper balance between generation-capacity reliability and economics in the ccompetitive electricit markets.