The benefits of distributed battery energy storage systems for customers and network operators based on measured data from deployed systems

The rapid growth in distributed energy resources such as solar photovoltaics and battery energy storage systems (BESS) has introduced unprecedented opportunities and challenges for the electricity sector. Although these systems increase the self-consumption of the customer, their integration requires further investment into the electricity network, and they reduce the revenue of the network operators. Conversely, there are opportunities to engage distributed BESS to perform multiple grid services that may benefit all customers and the network operator. Out of these services, the reduction of network demand peaks and photovoltaic export peaks are highly valued in the electricity sector. Currently, there is a lack of literature on detailed analysis of deployed, non-coordinated residential BESS and assessment of co-optimisation of commercial-scale BESS to maximise the financial outcomes for both the customers and the network operator. This thesis explores these gaps in the literature in the following contexts: i) the ability of residential BESS to reduce demand during network peaks, ii) the ability of residential BESS to reduce photovoltaic export peaks, and iii) the ability of commercial-scale BESS to be co-optimised for both the customers and the network operator. Analysing the measured data from deployed systems showed that on average, residential BESS that were operating as expected were already discharging to support the network during demand peaks but were unable to reduce photovoltaic export peaks because they were charged to full prior to the peak period. Different operational strategies for the BESS were modelled and it was found that setting a 27% limit on the batteries’ charging power can increase their export peak reduction from almost 0% to 15%, with no impact on their ability to increase self-consumption. A co-optimisation model was developed for a scenario of maximising the financial outcomes of installing commercial-scale BESS for both customers and the network operator. Although the outcomes are site-specific, the model could be used to assess the outcomes at different locations and under different assumptions. Taken together these findings should provide knowledge and methods that will contribute to the uptake of behind the meter BESS in a way that benefits all customers and the network operator