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Due to the recent COVID-19 outbreak and subsequent lockdowns in multiple countries, there have been reports of marked decreases in day-to-day pollution hanging over cities, such as this report on Beijing. This is being attributed in part to the lack of commuters going to work, with lots of workers across industries staying home under quarantine lockdown.

For some people, there is still the option to work from home. My question is, does working from home offer much from a sustainability perspective?

Take for example, a small office of 10 people, where:

  • The building is lit by fluorescent bulbs that supply light for the whole office.
  • Heated/cooled by a single HVAC system.
  • Communal shared appliances (printers, fridges, dishwashers etc).
  • Office supplies ordered in bulk (paper, pens etc)

vs those same 10 people working from home, having individual lighting, heating/cooling, appliances and supplies. There may be more points of comparison but these are the ones I can think of.

Which option is more sustainable, taking into account commuter transport, utilities, and so on? Have there been any studies done to this effect?

Robotnik
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    Three weeks ago, just after the start of the lockdown here in the Netherlands, the media reported that the power consumption of people working at home versus in an office is more or less the same. AFAIK hardly any factories are closed here, but the first results on air pollution published a few days ago reported that the air is now 20-60% cleaner because of the reduction in emissions from transportation. If only I could find the scientific studies this is based on..... – THelper Apr 01 '20 at 06:33
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    The US Energy Information Agency just published an update on electricity sales -- the total for all sectors was down 4% this year compared to last April. Data on natural gas and petroleum sales for April weren't available yet. – LShaver Jun 30 '20 at 16:12

1 Answers1

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Here's a piece of the answer for the U.S. Hopefully others can provide additional details covering other countries or regions.

MAJOR EDIT: Comments pointed out that something seemed fishy. I double-checked my numbers, and at one point I multiplied by 1,000 when I should have divided. Turns out that makes a HUGE difference.

Office building emissions

According to the U.S. Energy Information Agency (from Commercial Buildings Energy Consumption Survey 2012), there are 33.8 million office workers using 1.5 billion m2 of non-vacant office space in the U.S. (looking at office work only since it is the most likely candidate for the switch to telework).

CBECS also provides data on energy usage for office buildings:

  • 773 TWh of electricity (including transmission and distribution losses)
  • 83 TWh of natural gas (for heating and cooking)
  • 5 TWh of fuel oil (diesel, also for heating)

On average in the U.S., emissions factors for each of these fuels are as follows:

  • 0.45 kg CO2 per kWh -- total 347 million tons of CO2 (source)
  • 53.07 kg CO2 per million Btu of natural gas -- total 15 million tons of CO2 (source)
  • 78.79 kg CO2 per million Btu of fuel oil -- total 1.4 million tons of CO2 (ibid.)

Thus total annual emissions from office buildings is 364 million tons, or 10.77 tons per office worker per year.

Office commute emissions

According to a 2005 poll, the average American commutes 32 miles (51 km) a day. According to the same poll, 4% use public transit, and 8% carpool. If we assume the average carpool is two people, this means that 92% of office workers are driving 51 km a day -- about 31 million workers driving a total of 1.6 billion km per day. There are about 250 working days per year, so that equates to 400 billion km per year.

In the U.S., the average efficiency of vehicles on the road was 22.3 miles per gallon in 2017. This equates to 10.6 L per 100 km. Combined with km driven, this means Americans are using 42 billion L of gasoline per year to commute.

Combustion of gasoline results in emissions of 8.89 kg CO2 per gallon, or 2.35 kg CO2 per L.

Thus total annual emissions from workers commuting to offices is 99 billion tons, or 2.93 tons per office worker per year.

Comparison

There are series of assumptions and approximations here (please check my math, again!), but for the average office worker who commutes in a private vehicle in the U.S., emissions from the office are nearly triple the emissions from the drive.

If we say (for arguments' sake) that emissions from a home office per capita are the same as an office building per capita, then eliminating the commute results in a 20% reduction in emissions.

To fully understand the question, we'd need data on increased residential energy usage from teleworking. There are some estimates (here and here), but nothing thorough that I could find.

LShaver
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  • This is good info, thanks! It would be good to get some numbers for places where the mass transit usage is higher, as the commute may factor in differently. But for now, I'll accept this as you've covered the majority of what I was asking :) – Robotnik Apr 01 '20 at 23:09
  • Great collection of information. Are you making the assumption that when an individual worker works from home, the office building does not still consume that worker's worth of energy? The building will still be heated/cooled, appliances and equipment will still be run... To some degree doesn't the home energy consumption add to the office energy consumption instead of replace it? – electronpusher Dec 06 '22 at 01:10
  • I think 44 square meters per office worker is a bit excessive. The place where I work has about 15 square meters per office worker. Also 515 kWh electricity per square meter is just absurd and probably includes factories too. In Finland (a very cold country), 100 kWh per square meter per year is used for HEATING. Remember all electricity turns into heat. So if 515 kWh per square meter per year was used for e.g. computers and lights, it would turn into heat, and the heat would be so much it's 5x too much even for a very cold country. – juhist Dec 06 '22 at 07:32
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    Yes, the 773 TWh/year seems to be 22900 kWh/year per office worker. In United States, electricity usage per capita is 12300 kWh. That 773 TWh/year can't be possibly right. It's probably including factories and other large users of electricity. – juhist Dec 06 '22 at 07:39
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    @juhist all those numbers are straight from U.S. Energy Information Agency data, and I just went through and double-checked the numbers. Factories/industry is not included in the survey. You can see the definition used for office here. 44 m2 includes all spaces in the building such as conference rooms, lobby, cafe, etc, divided through by number of workers. The energy consumption includes cooling as well -- you can see intensities here. – LShaver Dec 07 '22 at 01:35
  • Land and energy are much cheaper (way too cheap) in the U.S. than almost anywhere in the world, which is why these numbers seem so ridiculous. And only about half of the population is employed (full time or otherwise), so that 12,300 per capita includes children and the retired. – LShaver Dec 07 '22 at 01:38
  • @electronpusher the assumption is that the energy consumption of both the home and the office are the same for each worker, and don't change regardless of where the worker is (home or office). This lets us focus on the impact of the commute relative to the office consumption. – LShaver Dec 07 '22 at 01:40
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    In addition to the home office energy, the office-office energy, and the commute, what about all the other things related to working out of the home? Coffee shops and lunch restaurants etc? Many of these have closed (and so are not emitting anything) due to lack of customers. Alternatively, some home workers are driving to not-very-local fast food places when they want something cooked for them instead of walking to the sandwich shop next to the office... people are taking trips to stores instead of getting stuff on the way home from work ... lot to consider really. – Kate Gregory Dec 07 '22 at 14:48
  • Do these estimates include emissions from office building construction / renovation? Ideally both the construction process and raw material extraction. – jrbe228 Feb 20 '23 at 02:53
  • @JeremyBeale no, the question and this answer assumes that the home and office are already built. Factoring the office construction would further tip the balance towards the home, since you'd still need a place to sleep even if you didn't need an office. – LShaver Feb 20 '23 at 16:04
  • Maybe that can be included on a future edit. The construction industry is massive. Estimated 13% of all CO2 emissions globally. Another potential edit could be a separate category for "non-office workers with WFH potential". More commutes potentially cancelled, although the OP's office emission numbers would remain the same. – jrbe228 Feb 20 '23 at 16:40
  • @JeremyBeale probably better as a new question, actually, since this one is in the context of covid. – LShaver Feb 20 '23 at 16:47