The 70MWp solar PV part of the project was completed in April 2023, becoming the first standalone solar PV plant to connect to the transmission network. Energisation of the 49.5MW/99MWh battery energy storage system (BESS) co-located with the solar development, makes the facility the first of its kind to be transmission connected in the UK.
The project has a 120MW grid connection, which, as commercial manager Patrick O’Connor told Energy-Storage.news, means “the BESS is not competing with the solar for export capacity”.
Marta Martinez Queimadelos, CEO of Cero Generation, who said she was “delighted” to have reached this milestone, explained: “This co-located solar and battery storage project will allow power to be delivered to the grid when it is needed, coupling demand and generation. The development of these projects will help to reduce the cost of energy for households, while also reducing the UK’s reliance on fossil fuels.”
Rabobank financed both the BESS and the solar PV elements. Cero generation and its UK development partner Enso Energy said that working on the project has established long-term partnerships with both Canadian Solar, as the lead on the engineering, procurement and construction (EPC) for the battery, and EDF, as the battery performance optimiser.
To connect the solar PV facility to the transmission network, Cero and Enso, in collaboration with National Grid, installed new switchgear at the site. A high-voltage cable also connected the solar farm to the Iron Acton substation near Bristol.
The partnership between Enso and Cero was originally signed between Enso and Macquarie’s Green Investment Group (GIG), before GIG launched Cero and consolidated its existing and future European solar activities, including the UK pipeline, into the new developer.
On 11 November, Solar Power Portal reported that National Grid had completed upgrades to its Drax 132kV substation to accommodate the transmission connection of TagEnergy’s 100MW/200MWh BESS.
According to the renewable energy developer, the facility in North Yorkshire is the largest transmission-connected battery storage system in the UK.
A connection to the higher voltage transmission system, rather than a local distribution network, means that the energy generated at a site, or discharged from a battery, can be transported across greater distances.