Glossary of Hornsea 3 terms

The Hornsea 3 project will also include a battery energy storage system that will help provide stability to the UK energy supply and reduce price volatility. On windy and sunny days, when renewable energy generation exceeds demand, the battery will store the excess energy so that it can be discharged later to balance the grid. 

With a capacity of 600 MWh, equivalent to the daily power consumption of 80,000 UK homes, the battery energy storage system will be one of the largest in Europe upon completion. 

The Tesla battery energy storage system will be installed on the same site as the project’s onshore converter station in Swardeston, near Norwich, Norfolk.

Pre-construction drainage is installed where necessary to keep the soil draining effectively during construction work. Post-construction drainage is later installed to help the land return to its former use.

Ducting is the term used to describe the pipes or tubes that are used to carry electricity export cables. Horizontal directional drilling is being used to install some of the ducting for Hornsea 3’s export cables. 

Energy balancing infrastructure manages the peaks and troughs in supply and demand of renewable energy by storing and supplying energy from renewable sources whenever it is needed.  

Hornsea 3’s energy balancing infrastructure facility will include a battery array, a control room, and electrical infrastructure which will connect it to the onshore converter station.

The renewable energy generated by the Hornsea 3 offshore wind farm will be connected to the UK’s National Grid via export cables.  

Mel Vila Flores is responsible for all of the onshore export cables for Hornsea 3 and explained how they work. 

“Think of electricity as a fleet of delivery trucks. Just like trucks need roads to transport goods, electricity needs its own pathways,” said Mel. “Export cables serve as the highways for electricity. They carry electrical energy from its source to where it’s needed – our homes, businesses, and communities.” 

Temporary haul roads are installed at various sites along the onshore cable route to create safe, designated routes for the movement of construction materials.

Jack-up installation vessels are equipped with legs to lift them above sea level. Standing firmly above the surface of the water, the vessels can operate safely and securely without being impacted by currents and waves.  

The Haven Sea Challenger jack-up barge was used off the coast of Weybourne to create a stable platform for the installation of the offshore cable ducts, or pipes, that will transmit the green electrical power generated offshore by Hornsea 3 to land.

Hornsea 3’s Onshore Converter Station will be in Swardeston, near Norwich, Norfolk. This electricity substation will take the renewable energy from the Hornsea 3 offshore wind farm, convert it to the appropriate voltage to allow it to feed into the UK’s National Grid. 

Reinstatement is the process of restoring a construction site to its original condition after the work is done. 

“Our pledge is to return everything as we found it,” Jason Ledden, senior director for Hornsea 3, explained. “When we excavate trenches to bury cables, we put them back neatly with the original material and topsoil. We replant vegetation and restore everything to the way we found it whilst working in cooperation with the landowner.”