The electrification of heat and transport will lead to increased loads and potentially congestion on LV networks. Voltage drop limitations may be mitigated by MV/LV on-load tap changing transformers, however in other cases thermal capacity of LV Circuits may prove a limiting factor.
Thermal capacity limits can be effectively overcome with conventional reinforcement, upgrading cables/lines and upgrading or installing additional transformers to reduce the load on certain circuits sections. Installation of new transformers can often prove an economic long term solution, but practical issues, such as finding a site for a new secondary substation, can limit ESB Networks’ ability to deliver this solution in existing housing estates.
Miniature secondary substations, known as sidewalk transformers, are a solution to such spatial restrictions as they can be installed next to the congested circuits, on the sidewalk itself, and without the need for a large new site as would be required for a conventional installation. This technology is already in use in Tokyo, Japan for many years. ESB Networks now proposes to develop similar units suitable for use on the Irish network, and evaluate the practical implications of their deployment on the network.