Energy usage in Ireland is affected by weather patterns and economic activity. Any analysis of energy efficiency measures must take these factors into account.
2008 was a cold year in Ireland - 20% colder than the previous year. The country was in recession, with a negative growth in GDP. This negative growth in GDP should have caused a drop in energy use. There was an associated drop in energy usage in industry and transport in 2008. However the energy usage in the residential and services sector was higher. This could be attributed to the colder temperatures, requiring more energy usage in heating in homes and businesses.
Ireland entered a deeper recession and this caused a decline in energy usage from the previous year in all sectors. 2009 did not have a similar dramatic change in temperature. Although the temperatures were still low, they were not significantly lower than the previous year. There was however a slight drop in residential energy usage. This could be due to energy efficiency measures or tightened household budgets due to the continuing recession. Percentage energy usage in industry, transport and services dropped at twice the rate of GDP.
2010 was again significantly colder than the previous year. There is an associated rise in residential energy usage. GDP is still declining, but not as quickly as in previous years. There is a strong increase in energy usage in industry. This may be because industrial output increased as the rate of decline of GDP slowed. Energy usage in the services sector also declines. This may be caused by reduced consumer spending due to reduced consumer confidence due to the previous recession years. There is a significant decrease in energy usage in transport.
In 2011 there was a small increase in GDP for the first time in many years. 2011 was also 20% warmer than the previous year. There was a significant reduction in energy usage across all sectors. The reduction in energy use in the residential sector was the most significant, continuing the trend of residential energy usage being closely linked to degree days.
Energy usage in Ireland is linked closely to temperature changes. This trend is strongest in the residential sector but can also be seen in the industry and service sectors.
There has been a consistent reduction in energy usage in transport. Energy usage in transport declines with a reduction in GDP. However there is also a decrease in 2011 when GDP rises. This could be explained by a general increase in efficiency in transport over the period. In 2008, changes to Ireland’s motor tax system were introduced. These heavily favoured more energy efficient cars. The gradual decrease in energy usage in transport could be partly attributed to the gradual modernisation of the motor fleet. Transport is not heavily affected by degree days.
Industry heavily reliant on GDP, but there also seems to be a slight correlation to degree days. Irish industries are not typically very energy intensive, so a significant portion of energy is used for heating.
Trend in energy usage in the services sector less clear. Both GDP and degree days seem to affect energy usage, but there are also other factors at play. Further work should compare energy usage in services to the consumer sentiment index.
Energy usage in the residential sector is very heavily influenced by degree days. A large portion of energy use in households is used for water and space heating.