Evaluation of Investment Deferral Resulting from Microgeneration for EHV Distribution Networks

Microgeneration (MG) comes in various forms, ranging from solar photovoltaic (PV), wind turbines, small hydro to solar water heating and among others. The governments in Europe see MG as a real alternative in reducing carbon emission and improving supply efficiency and security. Incentives for MGs are therefore on the rise, along with the number of units connected to the HV/LV distribution networks. These incentives typically bear no relation to the impact that MGs would have on the infrastructure network and on the generation supply. These un-directed incentives could bring unnecessary burdens to the energy system rather than help. Therefore, it is desirable to develop cost-effective incentives for MGs that can reflect the potential benefits/costs brought by MGs. Investment deferral is considered to be one of the most important benefits brought by integrating MGs into the distribution network. In this paper, the investment deferral is evaluated and quantified by connecting MGs at various locations and at differing penetration and concentration levels. This paper aims to achieve three goals: 1) to propose a method to assess investment deferral resulting from MGs for the EHV (Extra High Voltage) network; 2) to investigate how investment deferral varies with different MG allocation approaches in the network; 3) to suggest a more effective allocation approach which can bring more benefits to network investment deferral when the same quantity of MGs is connected. All the analyses are carried out on a subset of a practical system in the UK.