The relationship between PVDG technical impacts and DSO revenue: An approach to foster a higher share of non-firm PVDG integration

摘要

In meeting the EU 20-20-20 target, renewable non-firm photovoltaic distributed generation (PVDG) integration in low voltage distribution networks (LVDN) is inevitable. Statistically, accommodating such non-firm PVDG in the LVDN presents both technical and economic challenges to the distribution system operators (DSOs). Due to the intermittent nature of renewable energy sources, together with the temporal and spatial behaviour of domestic customers, increasing penetration of PVDG leads to uncertainty related to the core activity of the DSOs and recovery of revenue. Analysing the likely impacts of increased PVDG has brought about the need for studies to determine if regulatory policy has to consider a higher non-firm PVDG share to meet the EU 20-20-20 goal. DSOs are regulated by the national regulatory authorities (NRA) and their revenue is generated from the tariff structure set by the NRA. To this end, most EU LVDN domestic customers are charged per volume of energy consumed, whereas, most of the DSO costs are directly proportional to the capacity of the LVDN. With increasing penetration of PVDG in LVDN, DSOs could likely face a time-lag in recovering their revenue. In addition, the application of net-metering needs to be revised as it may result cross-subsidisation between different customers. The impact studies based on increased penetration of PVDG in a standard LVDN is the objective of this paper which will take into account both temporal and spatial behaviour. The potential revenue for the DSO under different distributions of PVDG will be computed. It has been observed from the results that as the penetration of PVDG increases reverse power flow can occur. Also, more than 50% of the PVDG installed customers can experience over-voltage at some point during the year if the PVDG peak increases. However, the network losses are almost constant throughout the year. But with increased penetration of PVDG, the annual revenue of the DSO is decreased by 20-30% of the reference revenue. This reduction in revenue is due to the assumption of a volumetric tariff in conjunction with net-metering. This impact needs to be evaluated holistically against the contribution of cleaner energy production and greenhouse gas reduction.