Quantifying the domestic electricity consumption for air-conditioning due to urban heat islands in hot arid regions

• Effects of urban heat islands on domestic electricity consumption for air-conditioning.
• Variation in electricity consumption is a direct result of modifications on urban microclimate.
• The domestic cooling load is up to 17–19% higher than the rural load over the year.
• Domestic electricity consumption in urban centres is higher than the rural consumption by 10%.
• Estimates of urban consumption based on data of airports cause an error that can reach 6%.

Authoritative reports show that building electricity consumption can increase steadily once temperature values within urban regions exceed their rural values. This study first assesses the role of higher temperatures in the variation of Bahrain’s domestic electricity consumption for air-conditioning, using the cooling degree days (CDD) as a quantitative index. It then examines how this consumption is affected by urban features. The assessment is performed using established scenarios of the urban heat island (UHI), advanced statistics of building stock and data for electricity consumption. Simple regression equations are developed to predict the effects of temperature alterations on the electricity consumption. This work shows that the variation in CDD is a direct result of modifications to the urban microclimate. The annual total urban CDD value is up to 17% higher than the rural CDD value. A sharp increase of up to 10% in electricity consumption for air-conditioning occurs in urban regions from April to October. Estimates of the electricity demand for dense urban centres that are based on air temperature values measured in open areas, such as airports, can cause an error of almost 6%. The developed statistical equations can be a valuable and convenient method of quantifying the domestic electricity consumption for air-conditioning in Bahrain and other Gulf countries.