Following the introduction of the Feed in Tariff (FIT), clusters of renewable generation are appearing on the Low Voltage (LV) network, and proposed programmes suggest that large numbers of connections could be carried out in relatively small geographical areas.

This intermittent generation exporting energy into the network is expected to cause a number of technical issues including: voltage rise, phase imbalance and harmonics.

Small scale renewables such as PV panels are usually connected to the low voltage network without a DNO's prior consent, in accordance with Engineering Recommendation (G83 stage 1), and have not so far been considered to be a significant problem. UK Power Networks has recently been assessing requests for large numbers of PV connection in relatively small geographical areas (G83 stage 2).

In response, UK Power Networks has developed a draft policy to provide guidelines for planners when more intensive studies are required, but this policy has necessarily had to make some simplifying assumptions.

Objectives

This project aims to carry out the following:

• Validate the assumptions within UK Power Networks draft guidelines and develop an approved policy.

• Gain a detailed understanding of the impact of PV on the LV network by monitoring several PV clusters (G83 stage 1 and 2) and covering different types of LV network. This will be achieved by equipping 20 secondary substations and 10 PV installations with LV network monitoring equipment. The monitoring will include networks without PV connections to create a clear baseline and develop a better understanding of the difference in voltage profiles and power flows. The trial will run for 24 months to capture seasonal variations

• Assess to what extent the information available to PV installers (e.g. monitoring of PV output) could be used by DNOs

• Investigate what innovative solutions can be applied to address network constraints. It is expected that the networks selected for this project will be used as trial areas for the solutions being identified.