Energy and the Environment

Energy consumption is also the subject of analysis and controversy when discussing time zones. Some claim that more natural light in the evening reduces energy costs by saving street lighting - in this scenario DST would be more advantageous. Others believe that more natural light in the morning reduces energy costs because heating costs are saved - in this case the standard time would be more advantageous. It seems reasonable to assume that heating costs outweigh electricity costs, since heating is more expensive than light, whereby the actual comparison depends on the climate of the respective country.

A study on Great Britain, for example, assumes that permanent DST could save 0.3% of electricity costs [HDGC10]. However, another study from 2009 estimated that permanent DST would increase electricity costs in Indiana by 1% to 4%, equivalent to nearly $9 million a year [KoGr09]. In most of the studies that show savings, these are less than 1% regardless of where the savings are seen (standard time or DST) and are largely contradicting [ArNe08, HaHI18].

A meta-analysis of the publications on the topic of clock change and electricity saving comes to the conclusion that the best estimate of the influence of the summer time on electricity consumption is close to zero [HaHI18, IrHH17].

Even taking into account the influence of the geographical latitude, the potential energy saving effect is not really recognizable [ArNe08, HaHI18]. For Germany, experts estimate the savings in electricity through the 7-month DST to be around 0.1% (corresponds to 10 million euros) [HaHI18, IrHH17] with however a possible increase in fuel consumption [HeBT93] .


Moving human activity earlier one hour, however, has an impact on the environment. A recent study shows that in the USA the number of fires increases by 30% when switching to DST, an effect that can be observed up to 3 weeks after the time change [Koun20]. Even if forest fires in some countries, such as Germany, do not usually pose a very great risk, an unnecessary increase in environmental pollution and destruction through artificial time systems such as DST is not ethically sustainable.