3.4.                  Assessment

3.4.1.             Construction

An assessment has been carried out based on the elements scoped into the assessment. The results in Table 3-3 and Table 3-4 provide the predicted GHG emissions arising from the Project.

The offshore Proposed Development is estimated to generate 6,226,793 tCO2e during the construction phase (2025 – 2032). The onshore Proposed Development construction phase is estimated to generate 33,769 tCO2e during the same period. In both cases the greatest GHG emissions are derived from the embodied carbon resulting from the production of the materials.

Table 3-3 – Offshore Proposed Development Construction Phase GHG Emissions

Table 3-4 – Onshore Proposed Development Construction Phase GHG Emissions

3.4.2.             Operation and maintenance

An assessment has been carried out based on the elements scoped into the assessment. This includes the lubricants and fuel required to operate the offshore substation platforms and wind turbines, and the additional distance travelled by ships using the alternative shipping routes. These GHG emissions constitute the operation and maintenance phase GHG emissions and are shown in Table 3-5. The Project is expected to operate for 35 years.

The consumption of materials during operation from the offshore Proposed Development is estimated to generate 5,197 tCO2e per year of operation. This will equate to 181,895 tCO2e during the entire operation and maintenance phase.

The GHG emissions resulting from the diversion of shipping routes would be 113,235 tCO2e in the first year of partial operation. GHG emissions are anticipated to decrease year-on-year for shipping in line with net zero targets for 2050. This assumes that the level of shipping on these routes stays at the same level as current.

Maintenance vessels will transit between port and site during the operation and maintenance phase of the Project. These vessels will begin this process in the first year of partial operation. During this first year, 12,500 tCO2e GHG emissions will be generated. It is assumed that the shipping sector will decarbonise at a steady rate in line with the UK Government’s net zero target and will be net zero by 2050.

Table 3-5 – Operation and Maintenance Phase GHG Emissions

Overall, the total GHG emissions resulting from the construction and operation and maintenance of the Project will be 7,638,930 tCO2e and are shown in Table 3-6.

Table 3-6 – Project Lifecycle GHG Emissions

3.4.3.             ELECTRICITY GENERATION

Due to the lower operational GHG intensity of the Project compared to the national grid GHG intensity projections, a net reduction in GHG emissions will be achieved as a result of the Project as offshore wind power is a less GHG intensive form of energy generation than the projected marginal generation in 2028 onwards, which includes a small residual amount of generation using unabated fossil fuels.

Electricity generation from the Project during the first full year of operation (when 4.1 GW of capacity is installed) is estimated to be 14,445,415 MWh. The Project is anticipated to produce 505,589,525 MWh of electricity over its 35-year operation and maintenance phase.

The average operational GHG intensity of the Project has been calculated at 2.8 grams of CO2 equivalent per kWh (gCO2e/kWh) by dividing the total operational GHG emissions by the total electricity generation of the Project. Construction GHG emissions have not been included within this calculation to allow a like-for-like comparison with the projected grid intensity, as the BEIS GHG intensity projections also only account for operational GHG emissions.

When compared to the current projections for the GHG intensity of marginal generation on the national grid from 2028 to 2067 (BEIS, 2021) as noted in Table 3-7, the GHG intensity of the Project is much lower throughout the entire operation and maintenance phase. This means that the Project will produce fewer GHG emissions per kWh of energy generated than the marginal generation sources it displaces from national grid supply.

Table 3-7 – GHG Intensity and GHG Emissions Saved by the Project

Based on the difference between the operational GHG intensity of the Project and the projected marginal GHG intensity for each year of operation, published by BEIS, it is estimated that the Project would save the amount of 9,178,312 tCO2e from being emitted into the atmosphere during its operation and maintenance phase (see Table 3-7).

3.4.4.             COMPARISON TO ALTERNATIVE FORMS OF ELECTRICITY GENERATION

The beneficial impact of the Project is further realised in relation to alternative forms of electricity generation.

This comparison uses a different GHG intensity to that presented in section 3.4.3 and accounts for construction GHG emissions to provide a like-for-like comparison from a lifecycle perspective.

Based on the total electricity generation of the Project and the lifecycle GHG emissions of 7,638,930 tCO2e, the lifetime GHG intensity of the Project is 15 gCO2e/kWh. This compares favourably with other low carbon energy generation and is significantly better than fossil fuel energy generation.  Table 3-8 outlines energy intensity ranges of alternative forms of energy generation (CCC, 2013). 

Table 3-8 – Comparison of Lifecycle GHG Intensities of Various Forms of Electricity Generation

3.4.5.             COMPARISON TO UK CARBON BUDGETS

The Applicant is committed to reducing GHG emissions wherever practicable and to supporting the UK and Scottish Governments in meeting their carbon reduction targets.

It is assumed that the construction phase takes place from 2025 to 2032 and that the GHG emissions resulting from this phase are spread evenly over this period. This period falls over the 4th (2023-2027) and 5th (2028-2032) carbon budgets of the UK Government.

The Project will operate during the entire 5th and 6th carbon budget periods. The operation and maintenance phase will extend until after the 2050 net zero target date.

Table 3-9 shows the proportion of the relevant carbon budgets that the Project would contribute to the UK Government’s 5-year budget period.

Table 3-9 – Comparison of Project to UK Government Carbon Budgets (tCO2e)

Note: This table does not include the GHG emissions resulting from the replacement of key offshore Proposed Development components as it is not known at this stage when any replacements might take place and hence into which carbon budget they would fall.

Table source: Advice on reducing the UK’s emissions - Climate Change Committee (theccc.org.uk)

3.4.6.             ASSESSMENT OF SIGNIFICANCE

The annual GHG emissions from the construction and operation and maintenance of the Project do not contribute to more than 0.24% to any of the UK Carbon Budgets that fall within this phase. Therefore, it is considered that the Project’s GHG emissions at no point will impact the UK Government’s ability to meet its Carbon Budgets. The UK Carbon Budgets align with the GHG emissions reduction trajectory required to limit warming to 1.5C, in line with IEMA guidance (2022) for determining significance, as noted in section 3.3.5.

Therefore, the GHG emissions resulting from the construction phase of the Project are considered to have a non-significant, minor adverse effect on the climate.

Despite the GHG emissions produced during the operation and maintenance phase, the Project is anticipated to save 9,178,312 tCO2e from being emitted into the atmosphere due to its lower GHG intensity than the grid’s marginal generation sources it displaces in the future baseline scenario. Without the Project, higher GHG emitting sources of energy generation will be required. Even when construction emissions are included in this equation, the Project would still save 2,951,519 tCO2e from being emitted into the atmosphere over its lifecycle.

The Project would take 8 years and 2 months to ‘pay back’ the GHG emissions relating to the construction phase from the start of the operation and maintenance phase.

The Project would begin providing carbon savings in 2036 and would continue to do so throughout its operational life. This would provide a beneficial contribution to both the UK and Scottish Governments in reaching their net zero targets by avoiding the release of GHG emissions to the atmosphere that would have been released by conventional sources of energy generation with higher GHG emissions.

This demonstrates how low-carbon energy generation sources such as this Project are crucial to the National Grid GHG intensity of electricity generation in the UK decreasing as projected.

The anticipated 9,178,312 tCO2e savings during the operation and maintenance phase mean that the Project would directly contribute to the UK and Scotland meeting their carbon reduction targets and results in GHG emissions being avoided from being emitted into the atmosphere. Therefore, the operation and maintenance phase of the Project is considered to have a significant beneficial effect on the climate.

Overall, the assessment has found that the Project would save 2,951,519 tCO2e GHG emissions from being emitted over the lifetime of the Project. This would provide a beneficial impact in relation to the UK and Scotland meeting their carbon reduction targets and cause GHG emissions to be overall avoided from the atmosphere. Therefore, the Project is considered to have a significant beneficial effect on the climate.

3.4.7.             CUMULATIVE EFFECTS

The effects of GHG emissions are essentially cumulative; it is their concentration in the atmosphere, not the actual level of GHG emissions, that determines the warming effect (i.e. it is the ‘stock’ rather than the ‘flow’ which is important). In addition, it is the global excess of GHG emissions from human activities all over the world that contributes to the overall effect on climate, not only local GHG emissions. And it is the global atmosphere that is the receptor for these GHG emissions. For these reasons, the impact of the Project should be considered in the context of overall GHG emissions from the UK and globally. As noted in the IEMA guidance, the effects of GHG emissions from specific cumulative projects should not be individually assessed as there is no basis for selecting any particular project over any other.

The Cambois connection[7] will export electricity from the offshore Proposed Development array area to the National Grid via a grid connection at Blyth substation, Northumberland. The Cambois connection will be constructed during a two-year period between 2028 and 2031. It would only be constructed if the Project is implemented. Since the Cambois connection is therefore directly dependent on the implementation of the Project, a cumulative assessment of the GHG emissions associated with the Cambois connection together with the onshore Proposed Development and the offshore Proposed Development is presented here in order to provide a precautionary, worst-case assessment of potential GHG emissions.

Since the Cambois connection is at the scoping stage, full design details are not known at this stage, but the worst-case scenario for the construction phase GHG emissions is estimated to be 337,935 tCO2e. The vast majority of these GHG emissions are embodied GHG emissions from the four export cables used along the up to 170 km offshore export cable route.

The GHG emissions for the operation and maintenance phase are not known at this stage but are considered to be minor. This is due to the likely limited operational energy and maintenance requirements associated with the export of electricity.

Table 3-10 compares the cumulative GHG emissions of the two projects with the UK carbon budgets. As the Cambois connection is due to be constructed within a two-year period between 2028 to 2031, the cumulative GHG emissions will only occur during the 5th UK carbon budget. The two projects combined will release 4,523,604 tCO2e during the 5th carbon budget. This equates to only 0.26% of this UK carbon budget.

Table 3-10 - Comparison of Cumulative GHG Emissions to UK Government Carbon Budgets (tCO2e)

The cumulative GHG emissions from the two projects do not contribute to more than 0.26% of any of the UK Carbon Budgets that fall within the construction and operation and maintenance phases of the Project. Therefore, it is considered that these cumulative GHG emissions will not impact the UK Government’s ability to meet its Carbon Budgets. The UK Carbon Budgets align with the GHG emissions reduction trajectory required to limit warming to 1.5C, in line with IEMA guidance (2022) for determining significance.

Taking the GHG emissions from the Cambois connection into account results in saving 2,613,584 tCO2e from being emitted into the atmosphere during the lifecycle of the Project.

Whilst the GHG emissions resulting cumulatively from the Project and the Cambois connection are considered to have a non-significant, minor adverse cumulative effect on the climate, they only occur cumulatively during the construction phases of both projects. The Project’s significant beneficial effect on the climate during the operation and maintenance phase is not changed when taking the Cambois connection into account, nor is the overall significant beneficial effect of the Project on the climate during its lifetime.