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Chart of the Week


Get a load of this! Wind output in January 2020

Tim Dixon
Tim Dixon Wholesale Team Leader

January 2020 was a ground breaking month for renewables, as National Grid ESO announced GB’s electricity system was the greenest on record. Transmission-level wind generation was 6.3TWh across the month.

High wind output has been aided by new capacity additions with projects such as the 285MW East Anglia One Phase 2 commissioning at the end of 2019 under the Contracts for Difference (CfD) scheme. These newer sites utilise the most advanced technologies, including larger turbine sizes, and are becoming notably more efficient than their predecessors. This efficiency is reflected in their load factors, which depend on their technology type – i.e. offshore or onshore – but also on the age of the site.

“Some of the newest offshore and onshore sites saw monthly average load factors close to, or above, 70% for the month of January, and on some days approached 100%.”

As a result of the elevated wind speeds experienced in January, onshore wind load factors averaged 42% for the month, and older offshore sites (pre-2016) reached an average of 52%. Demonstrating the rising efficiency of newer (post-2016) offshore wind farms, load factors averaged 55% for these sites. These are some of the highest load factors seen since the latter end of 2015. Some of the newest offshore and onshore sites saw monthly average load factors close to, or above, 70% for the month of January, and on some days approached 100%.

Our Chart of the Week highlights the monthly average load factors for wind technologies, across a sample of around 120 sites that we track. In the chart, we distinguish between offshore and onshore wind technologies, as well as by the commissioning year of the sites.

The chart shows differences in the performance of wind sites, with a trend line clearly seen in higher load factors for newer sites. This is likely due to the utilisation of larger turbines. With a further 1.1GW of new offshore wind capacity expected to be operational by April 2020 and with government aims to have 40GW of offshore wind by 2030 (up from today’s 10.8GW), these wind output records are likely to be broken more frequently.

Whilst a positive trend towards decarbonising the electricity mix, high levels of wind output are not without impacts. For one, all other things being equal, it causes lower wholesale power prices, often meaning that wind farms (bar those protected under the CfD), see reduced £/MWh revenues at times of high output. They can even cause negative prices, as seen for some day-ahead prices in December 2019.

There are also wider system impacts from increasing yield and the geography of wind assets. With the majority of onshore capacity in Scotland, limited transmission system capacity means that wind output is often constrained, resulting in additional consumer costs through the Balancing Mechanism and a reduction in wind output, something we will analyse in future Charts of the Week.


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