Tag Archives: energy index

By Rachel Duggan

The BrightWind Wind Map shows that annual wind speeds in 2022 reflect the long-term average across the island of Ireland.

  • The wind speed last year was within 0.5% of the long-term mean.
  • The wind speed frequency distribution from year-to-year was less consistent than normal.
  • The lowest relative wind speeds were in the south of the country, increasing towards the north-west.
  • Taking Galway as an example, the energy output for 2022 was up 3.1% on the long-term due to the difference in frequency distribution.


Continue reading for a more detailed comparison across 5 Irish regions.

BrightWind Wind Map shows the relative change in mean wind speed of 2022 compared to the long-term (2000-2021).

Ireland as a whole

The BrightWind Wind Map shows the windiness, or wind index, of 2022. It compares the short-term mean wind speed by normalising it against a long-term period (2000-2021). Looking at Ireland as a whole, last year was pretty on par with the mean wind speed being 99.6% of the long-term mean. This is a recovery from 2021’s low.

Annual mean wind speed, normalised by the long-term period, for Ireland over the previous 23 years showing last year to be comparable to the long-term mean (2000-2021).

Windiness by region

When comparing 5 areas (Carlow, Cavan, Donegal, Galway, and Kerry) there are some variations between the locations but the general trend is the same.

  • A weak January counteracts unusually high wind speeds in February.
  • Spring saw fluctuations in wind speeds which reduced to lows in August and September.
  • The highs of October and November contradicted a low December.
  • Resulting in near-typical wind speeds, on average, by the end of the year.


The trend for Galway is shown as an example here, but you can view trend for all 5 sites at the end of the article.

Windiness in Galway for 2022 and the long-term period (2000-2021), follows the same trend as other 4 regions analysed.

Although the mean wind speed last year was similar to the long-term, this was not the case for the frequency distribution, as shown below. Looking at Galway, the production in 2022 was 3.1 % above the long-term mean when put through a typical power curve (the SWT-2.3-101 in this case).

Wind speed frequency distribution across Galway for 2022 and the long-term period (2000-2021) showing a difference at all wind speeds.

Below are the wind indices, for the 5 locations, on a monthly basis and adjusting for seasonal effects. So, how have your assets performed in the context of 2022’s wind speeds? Contact me (rachel@brightwindanalysis.com) to help you find out.

Carlow

Windiness in Carlow for 2022 and the long-term period (2000-2021).
Seasonally adjusted windiness in Carlow showing extreme variations in February, late summer, and early winter.

Cavan

Windiness in Cavan for 2022 and the long-term period (2000-2021).
Seasonally adjusted windiness in Cavan showing extreme variations in February and October.

Donegal

Windiness in Donegal for 2022 and the long-term period (2000-2021).
Seasonally adjusted windiness in Donegal showing an extreme high in February.

Galway

Windiness in Galway for 2022 and the long-term period (2000-2021).
Seasonally adjusted windiness in Galway showing an extreme highs in February and early winter.

Kerry

Windiness in Kerry for 2022 and the long-term period (2000-2021).
Seasonally adjusted windiness in Kerry showing extremes in February, late summer, and early winter.