The coronavirus pandemic is systematically demolishing the entire concept of efficiency.

Why it matters: Using energy more efficiently accounts for the largest share — nearly 40% — of the reductions in heat-trapping emissions needed to meet the goals of the Paris Climate Agreement.

The big picture: The virus, almost by design, hates efficiency of all kinds, energy included.

• Public transit, where a bunch of people move together in one vehicle, is the pinnacle of efficiency. Its use has plummeted and stayed down.
• In-person school features an efficient teacher/kid ratio of (roughly) 1:23. Ad hoc virtual school has a grossly inefficient ratio closer to 1:1. It’s also, of course, deeply disruptive to parents.
• Single-use plastic, by definition not efficient and wasteful, is coming roaring back amid fears thatthe virus is lurking on reusable menus, bags and cups.

Driving the news: The pandemic is dismantling energy efficiency in three ways:

1. It has stalled retrofits in homes and buildings given the fear of close contact. This has also cost hundreds of thousands of jobs, according to Steve Nadel, executive director of the American Council for an Energy-Efficient Economy.
2. Our society’s immediate chaotic response is wasting a lot of energy — such as big buildings sitting mostly empty but still guzzling energy, and public transit still moving but carrying few passengers.
3. Absent policy change, our medium to long-term response is probably going to use energy less efficiently. This includes using heaters to warm the outdoors, recycling more outdoor air into ventilation systems, and — perhaps most ludicrous — “flights to nowhere” that begin and end at the same place.

Where it stands: Overall electricity use in America was actually up slightly in July compared to the year before, according to a new working paper by Tufts University economist Steve Cicala.

That’s because residential energy use is higher with more remote work than it was the same time last year, offsetting the declines in industrial and commercial sectors. (On a yearly basis, power usage is still expected to be down 2.2%.)

• Remote work on some level is likely to stick around permanently, resulting “in a mixed format where both offices and homes are simultaneously drawing power,” writes Cicala, who is also a non-resident scholar at the Energy Policy Institute at the University of Chicago.
• Meanwhile, driving, which plummeted as lockdowns took over in April and May, is pretty much back to normal. People are still commuting to work less, but they appear to still be driving (somewhere).

How it works: There's a lot of inefficiency in the way buildings — like offices and schools — operate. Buildings, including commercial and residential, account for 40% of U.S. greenhouse gas emissions.

• Despite virtually all major U.S. cities locking down in April and May and offices emptying out, energy consumption by commercial buildings declined just 15%, Cicala’s research shows.
• It’s not as easy as simply turning off the lights. The way buildings are owned, rented and operated make it more difficult than it may seem to turn on and off certain systems, such as heating and cooling equipment, experts say.

What they’re saying: Nadel, of the efficiency council, says some building operators are running their ventilation systems more frequently and with more outdoor air to ensure better air flow to fight the coronavirus. This could double or even triple energy use.

• His colleagues in the private sector agree. “We’re looking at a really different world when we have to simultaneously address the COVID-19 threat from an indoor air quality perspective and we don’t want emissions and energy use to go up,” said Clay Nesler, vice president of global energy and sustainability at Johnson Controls.
• “We need to do it in the most efficient way possible. It is an interesting challenge.”

Yes, but: It’s not all bad news. Both short-term and longer-term efforts are underway that could give a boost to energy efficiency.

• California is retrofitting school HVAC systems to be both safe for COVID but also more energy efficient, a move other states and localities are likely pursuing as well, experts say.
• Energy efficiency is the cornerstone of a lot of the green components of economic recovery plans, especially in Europe. This is partly because making buildings, appliances and other societal essentials more efficient requires a lot of labor, which means more jobs for the millions unemployed.

The bottom line: “Overall, we reckon investment in energy efficiency will be down 12-15% in 2020,” said Brian Motherway, who is the International Energy Agency’s lead expert on the topic.

• “But, driven by economic stimulus actions we’re starting to see, there’s every chance we could see a full rebound in 2021 if that trend continues.”