The sensitivity of present-time electricity demand on past climate change: a case study for Italy

Simone Scapin,Maurizio Maugeri,Michele Brunetti,Francesco Apadula

doi:10.1186/s40322-015-0030-7

Abstract

Abstract A methodology for estimating secular daily minimum, mean and maximum (Tn, Tm and Tx) temperature records for any urbanised point of a 30-arc-second-resolution grid covering Italy is presented. It is based on the superimposition of 1961–1990 climatologies and departures from them (anomalies). The anomalies are obtained by applying inverse distance weighting to 143 Italian high-quality records, whereas the climatologies are based on a larger dataset and on the application of local weighted linear regression of temperature versus elevation. The grid-point Tn, Tm and Tx records are then used to set up secular records (period 1801–2013) of temperature-derived variables that influence Italy present-time national electricity demand. They are national averages over Italian urbanised areas of cooling degree-days (CDD), heating degree-days (HDD) and solar radiation deficit with respect to a defined threshold (S), with solar radiation estimated using daily temperature range as a proxy. The monthly and yearly sums of the daily CDD, HDD and S records are then used, alongside with a model allowing to link these variables to present-time Italy electricity demand, in order to understand the impact of climate variability and change on present-time Italian electricity demand. We find that temperature changes as the ones observed in the last two centuries are capable of altering significantly the present-time monthly profile of the electricity demand, raising (lowering) summer (winter) months contributions. The impact is higher in summer months where it exceeds 5 % of present-time Italy average monthly electricity demand, whereas the decrease of the winter demand is rather low because of a very limited use of electricity for heating. The summer and winter opposite-sign changes result globally in an increase of the yearly demand of about 5 TWh, corresponding to about 1.5-2.0 % of present-time Italy yearly electricity demand.

Highlights

Spatial climate datasets in digital form are currently in great demand and gridded estimates of 30 years climatological normals are requested by a variety of models and decision support tools, such as those used in agriculture, engineering, hydrology, ecology, energy management and natural resource conservation (Daly et al 2002; Daly 2006)
After these parts on the meteorological data, we discuss the method we use to set up national average records allowing to capture the dependence of present-time Italy electricity demand on meteorological variables; we present past variability and change of these records and discuss the relevance of their changes on the light of the sensibility of Italy present-time electricity demand on cooling degree-days (CDD), heating degree-days (HDD) and S
This paper focuses on the impact of climate change on CDD, HDD and S and on the corresponding impact on present-time electricity demand

Summary

Introduction

Spatial climate datasets in digital form are currently in great demand and gridded estimates of 30 years climatological normals are requested by a variety of models and decision support tools, such as those used in agriculture, engineering, hydrology, ecology, energy management and natural resource conservation (Daly et al 2002; Daly 2006). Variability and change of CDD, HDD and S from the beginning of the 19th century to present can be used, alongside with the model proposed by Scapin et al (Scapin et al 2015), to get a rough estimation of how the present-time electricity demand would be if the climate were still in the situation prior to global warming.

Results

Conclusion