The point of connection to the national grid is primarily via a substation and should be a key criterion in the selection of a solar farm site and should be considered at the outset of any proposal in consultation with National Grid. Locating solar farms in close proximity to available grid connection capacity enables the maximisation of existing grid infrastructure, minimising disruption to local community infrastructure or biodiversity and reduces overall costs. Where this is the case, consideration should be given to the cumulative impacts of situating a solar farm in proximity to other energy generating stations and infrastructure. Solar Farms are required to connect into the transmission network via an existing, which may require extending, or new electricity substation. A solar farm proposal may also require an on-site substation to take the electricity generated from the PV panels and Battery Energy Storage System (BESS) up to the right voltage for onward transmission to the Grid.

A substation is considered `associated development’ and should be considered alongside any solar farm proposal and be subject to the same detailed siting option appraisal and preliminary environmental assessment. Alternative locations for any substations and BESS should be considered and assessed on a comparable basis. It is advised that solar farm proposals and their associated development is considered together to enable the consideration of cumulative impacts in the Environmental Impact Assessment (EIA) process, in Preliminary Environmental Information Reports (PEIRs) for Nationally Significant Infrastructure Projects (NSIPs) and on local communities.

Underground cabling systems are encouraged over the use of overhead powerlines to connect to the national grid and the draft National Planning Policy Statements (NPS) for Electricity Networks Infrastructure (EN-5) should be referenced. An optioneering process should be undertaken to identify the cable route corridors that have been considered and include technical and engineering requirements, planning, environmental, land use and ownership constraints with a comparable assessment of each option against specified criteria. Any need for overhead gantries and temporary diversion works to overhead lines to enable connection to the grid should be minimised.

Any associated development and the necessary underground connection to the grid will be required to consider the standard EIA topics of climate change; cultural heritage; ecology; flood risk, drainage and surface water; landscape and visual amenity; noise and vibration; socio-economics and use; transport and access; air quality; ground conditions; human health and waste. In addition, consideration will be required to be given to the scale and design of development, soil stripping, storage and excavation for site compounds, cable routing impacts and access for maintenance. All proposals will be required to consider their individual and cumulative impact during construction and decommissioning phases.