The abolition of daylight-saving time is a frequently - and heatedly - debated issue.
Frequently, only the aspect of electricity consumption due to artificial lighting is taken into account.
Researchers have now examined whether daylight saving has an effect on the amount of heating and cooling energy required for office buildings, and what role climate change may play in this.
The results should please proponents of daylight-saving time.
Leaving The House Earlier Saves Energy
SEBASTIEN SALOM-GOMIS/AFP via Getty Images
With the start of daylight-saving time, debates erupt, as they do every year, about whether or not the time change should be abolished, both in politics and in society at large, as per ScienceDaily.
Opponents argue that the time change has an impact on our health, such as sleep disruptions.
Proponents, on the other hand, frequently make the case for saving electricity because longer days require less artificial light.
"That was the original intention behind the introduction of daylight saving," Sven Eggimann explained.
However, from Eggimann's perspective, it makes sense to look not only at the impact on electricity savings in lighting, but on the overall energy consumption of a building.
He has thus determined whether and how the time change affects heating and cooling energy consumption in collaboration with his colleague Massimo Fiorentini and other colleagues at Empa's Urban Energy Systems Lab.
The scientists hypothesized that because of the time change, employees start their work an hour earlier in the summer and leave the office an hour earlier in the afternoon.
Because most cooling occurs later in the afternoon, this can save energy.
The assumption is that in an empty office, cooling can be reduced or even turned off entirely.
This would be relatively easy to achieve in the future as buildings become more intelligent.
To test the hypothesis, the researchers used data from various office buildings in 15 US cities to simulate the heating and cooling energy used with and without daylight-saving time for different climatic regions.
They considered not only the current climate, but also future climate scenarios up to the year 2050 in order to include the influence of climate change.
This is critical because climate change has a significant impact on the energy consumption of a building.
In another study, Empa researchers discovered that, as a result of climate change, Switzerland's demand for cooling may eventually equal that for heating.
The current study's findings should please supporters of daylight saving time.
"Switching to daylight-saving time can reduce an office building's cooling energy by up to nearly six percent while increasing heating demand by up to 4.4% due to an earlier start of work in the morning," explained Massimo Fiorentini.
However, because much more cooling than heating energy is required in summer, the time change has a positive overall effect on the energy balance of a building.
Overall energy savings varied across climate zones and scenarios, peaking at around 3%, but they were visible everywhere.
Although this result only applies to office buildings in the United States, it provides useful insights for Switzerland because the climatic conditions for several of the simulated climate zones are comparable.
Eggimann demonstrates how time change can help to protect the environment.
In the debate over eliminating daylight-saving time, policymakers should consider not only the electricity savings from artificial lighting, but also the impact on the overall energy balance of office buildings, as per Eurekalert.
At the same time, the researchers emphasize that changing the time is only one of many factors that can affect a building's energy consumption.
Building technical improvements, behavioral changes, and a general adjustment of our working hours can all contribute to energy savings and thus CO2 reduction - whether or not we change the time every six months.
