Our changing lifestyle seems to be saving a lot of energy
When it comes to the environmental impact of humans, it’s best for the soul to look at things with a ‘glass half-full’ outlook as much as possible. So while it’s true and thoroughly depressing that human activity is the driving force behind catastrophic climate change, and our consumerist lifestyle is causing terrifying amounts of e-waste, we are at least moving in the right direction in terms of energy consumption.
That’s the verdict of a new paper from the University of Texas in any case. Postdoctoral fellow Ashok Sekar and his team examined a decade’s worth of American Time Use Surveys between 2003 and 2012 and discovered that US citizens are cumulatively saving an estimated 1,700 trillion BTU in energy thanks to gradual shifts in the way we live our lives. Sekar tells me that although more up-to-date surveys exist, energy measurement data for the same period wasn’t accessible. His feeling, though, is the lifestyle changes driving the trend will only have accelerated in the intervening years.
Broadly, said changes fall to the increased amount of time Americans spend in the home. Compared with 2003, in 2012, Americans spend an additional eight days at home, transferred from eight days in commercial buildings and one day travelling. That’s likely to be a mix of flexible working, the rise of internet entertainment and online shopping – three changes that had really begun to take hold between 2003 and 2012. An illustrative point of the latter two: in 2003, Netflix was celebrating its one-millionth American subscriber – by 2012, it had increased 27-fold. During the same space of time, Blockbusters – a rival that required people actually leave the house – went from 9,000 brick-and-mortar stores worldwide to the verge of liquidation. That’s small-fry in the greater scheme of thing, but a neatly illustrative example of how our lives have shifted quite rapidly.
“We did expect to see net energy decrease, but we had no idea of the magnitude,” Sekar said. “This work raises awareness of the connection between lifestyle and energy. Now that we know people are spending more time at home, more focus could be put on improving residential energy efficiency.”
At first, it feels somewhat counterintuitive that spending more time at home would lower energy usage. After all, humans sharing energy costs in communal spaces surely reduces our overall burden, right? In theory, yes, but in practice, it’s quite different, once the BTU/person/minute amount is calculated, Sekar explains when I put this to him. “In the U.S. the total energy use of residential and commercial sector is ~20,000 trillion BTU and ~18,000 trillion BTU,” he adds, which isn’t a huge difference considering the time discrepancy: roughly 17 hours at home, and 5.5 hours outside.
Eric Williams, a sustainability research from the Rochester Institute of Technology and a co-author on the paper has some additional thoughts. “Commercial buildings use a lot more energy per square foot than home,” he explains. Around four times as much, to be precise. “Thinking of a retail store, the entire area is super lighted and at constant thermostat temperature from open to close (and beyond), regardless of how many people are in the store. During non-crowded times, energy per person is going to be orders of magnitude higher than a house.”
Additionally, Williams adds, behavioural changes from telework aren’t really impacting on individuals’ home energy uses, but are having an effect on workplaces. “Most people in the U.S. weren’t changing their thermostat when they were out, so staying home doesn’t add – when averaging over a bunch of people – much additional energy,” he says. “But with enough telework, businesses can switch to shared space/contract workers and eliminate the entire office space.”
And what about the impact of home delivery on the planet? The energy required to package, ship and deliver parcels isn’t insignificant, surely? “If packaging is done in the U.S. it would come under commercial sector and therefore that would be included in the model,” says Sekar. Although he notes that shipping wasn’t included in the calculations, past research indicates that online shopping is more energy efficient than people heading out to a retail store en masse. “Imagine everyone in your neighbourhood going to a local supermarket for buying their groceries vs. a truck driving around multiple neighbourhoods and dropping off packages,” he explains.
Of course, this study is looking purely at America – but it’s not a bad place to start, given it’s a country of 323 million, with the second-highest electricity consumption in the world. There will likely be differences between countries: Williams speculates from his time living in Japan that the trend might be reversed due to air conditioning and heating being turned off when properties are vacant, and crowding means that offices and shops tend to be busier. There will likely be differences in cities where good public transport infrastructure means most citizens avoid the roads entirely.
“We did not perform that analysis although the model can be improved provided city-specific data,” Sekar says. “In fact, the time-use trend may be more stark, with more time at home compared to non-cities due to various reasons including high traffic and large availability of work from home jobs etc.” But this is all speculation, he stresses.
It’s tempting – and often correct – to think that the majority of recent changes to our lifestyle have been bad for the planet. Our carbon footprint, meaty diet and rampant consumerism all attest to this philosophy. But in electricity consumption, at least, there may be something to say for our new way of life after all.