The 400MW of installed electrical capacity will generate 1,366GWh1 (Gigawatt hours) of power output each year from a clean, renewable energy source. The power will supply the equivalent of up to 290,000 homes2 each year for the lifetime of the project, that’s the equivalent of more than 4 in every 10 homes in the whole of Sussex, including Brighton & Hove3.
We estimate that the project could avoid the emission of almost 600,000 tonnes4 CO2 per year (587,000 tonnes). We know this because electricity generation and demand is actively balanced, every minute of every day by National Grid, to ensure that supply and demand are always precisely matched. Since wind energy is accepted onto the grid as and when it generates, conventional generators are required to reduce their generation and in turn, the amount of fuel and CO2 released. Therefore we can calculate how much CO2 would have been emitted from the fossil fuel generators displaced.
1 Assumed capacity factors for offshore wind, The Contracts for Difference (Standard Terms) Regulations August 2014, DECC. Generation: 400MW x 0.39 x 8760 x 1,000 = 1,366,560,000KWh / 1,367GWh pa)
2 Based on an average annual domestic household electricity consumption of 4,700kWh (DECC):
1,366,560,000KWh / 4,700KWh = 290,757 homes
3 Office National Statistics Census data 2011
4 Every unit (kWh) of electricity produced by the wind displaces a unit of electricity, which would otherwise have been produced by a power station burning fossil fuel. This is a generally accepted fact used by many organisations including Government in their environmental calculations. Wind-generated electricity does not replace electricity from nuclear power stations because these operate at 'base load', that is they will be working for the whole time that they are available. The calculation is made using a static figure of 430g CO2/kWh representing the energy mix in the UK.