Despite our offshore windfarms being out at sea, we have to connect to the National Grid onshore using a substation/converter station. To get power generated offshore to our substations/converter stations, cabling must be laid underground. The point where our offshore sub-sea cabling reaches land is called the Landfall point.
Throughout the construction of substations/converters stationand the laying of onshore cabling, a multitude of ecology measures are put in place to minimise our impact on neighbouring wildlife ecosystems, animal habitats and the surrounding environment.
Mitigation Throughout Construction
Prior to any development the environmental aspects of a proposed development location are assessed in detail for potential impacts to protected species, habitats, and the overall landscape. Numerous onshore ecological and environmental surveys are undertaken including habitat classification, protected species targeted surveys, watercourse condition surveys, baseline noise and lighting, and geological, hydrological, and visual landscape assessments.
The assessments help with the selection of sites to avoid the greatest impact. Where impacts cannot be wholly avoided these are mitigated for prior to or throughout construction.
Some of the key mitigation ahead of construction works is for ecological aspects, this may be closing and/or relocating badger setts that may otherwise be damaged, compensating for terrestrial amphibian habitat, closing and relocating bat roosts, temporarily displacing water voles and otter from sections of watercourses and managing vegetation ahead of works to remove potential for uptake of species.
Some of the key species mitigated for across our East Anglia ONE and East Anglia HUB projects including great created newts, badgers, marsh harriers, water vole, stag beetle, slow worm, wintering birds and jersey cudweed.
Mitigation Following Construction
Following construction, the temporary working corridor for the onshore underground cable route is reinstated. The majority of this is reinstatement of agricultural soils. Key aspects on our East Anglia ONE onshore work also included replanting 3500 linear metres of native hedgerows and grassland seeding according to habitat type such as roadside verges/field margins or specific acid grassland mixes. Furthermore, for every tree removed during construction, we replanted 2 in its place totalling 1700 new trees planted along our construction route.
Around the new Substation/Converter Stations extensive landscaping is undertaken to screen the development as well as provide extensive biodiversity gain. Surrounding the East Anglia ONE substation/converter station over 30,000 trees have been planted creating several areas of broadleaved and mixed woodland, as well as 12.6 hectares of species-rich grassland, 1600 linear metres of native hedgerows and two Sustainable Drainage System (SUDS) basins. The main SUDS provides a permanent pond area with planted aquatic flora which has established a diverse species assemblage from dragonflies and damselflies to amphibians including great crested newts, and various notable bird species such as stonechat, green sandpiper and jacksnipe.
The landscaping also included ecological enhancements such as bird nest boxes, bat roost boxes, hibernacula and log piles and barn owl boxes to aid uptake of the area whilst habitats mature. The East Anglia THREE Converter Station currently in construction will include additional landscaping to further screen both projects, providing increased biodiversity including woodland, hedgerows, grassland and a SUDS basin designed to provide a permanent pool area to maintain aquatic habitat year-round.