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The challenges of building electrification — or, the parable of flameless wok hei

The tension between gas-fired woks’ unique capabilities and their outsize climate footprint is evocative of the wider challenges to decarbonize commercial buildings.

cooking vegetables in a flaming wok

Consider the humble wok. Little more than a wide metal bowl, a good wok can transmute high heat and simple ingredients into sublime flavors. Peek in the back of your favorite Chinese hole-in-the-wall and you may spy a chef calmly working the mix as flames engulf the wok and powerful jet burners roar below. A chef can spend years perfecting this fusion of fire and heat, oil and spice — or wok hei, the "breath of the wok." 

Elemental as they may be to Chinese cuisine, gas-fired woks are wildly inefficient. More of their heat is wasted than is used. Harmful combustion byproducts, such as carbon monoxide, can spike to levels far higher than allowed by safety codes. And much of the excess cooking heat radiates beyond the kitchen, boosting costs to cool and vent neighboring spaces.

The tension between gas-fired woks’ unique capabilities and the challenge of finding a good substitute given their outsize climate footprint is evocative of the wider challenges to decarbonize commercial buildings. And the urgency to find workable solutions is rising. 

More regions are advancing plans to curtail natural gas, a powerful greenhouse gas. Since 2019, when Berkeley, California, became the first U.S. city to pass a ban to discourage the use of natural gas in new homes and buildings, big cities including Denver, New York, Seattle and San Francisco either have introduced or approved similar rules. 

Homes and businesses account for about 13 percent of U.S. greenhouse gas emissions, with a large share of that coming directly from the combustion of natural gas to cook food, fire furnaces and heat water, as well as to wash and dry laundry. Methane — the main ingredient in natural gas which frequently leaks — traps 80 times more heat than carbon dioxide in the atmosphere. Curtailing the installation of new natural gas capacity, let alone retrofitting the millions of buildings that rely on it today, amounts to a monumental challenge. 

Efforts are advancing, whether for new construction (easier), retrofits (harder) or even restaurant electrification (among the hardest).

But the consensus view from a group of building professionals who gathered virtually for VERGE Electrify last month reflected progress for electrification. Efforts are advancing, whether for new construction (easier), retrofits (harder) or even restaurant electrification (among the hardest) — including, yes, those woks. Here are some highlights:

Bigger, taller, better buildings. Just five or 10 years ago, green building pros frequently faced fundamental doubts about electrification, those "Can it be done?" sorts of questions. "We’ve passed that," said Shawn Hesse, business development director at the International Living Future Institute (ILFI), a nonprofit that established the Living Building Challenge in 2007. "Today we get questions about scale and complexity." From tens of thousands of square feet a few years ago, "We’re seeing projects come through that are a million square feet or more today." 

Advancing ambitions. In that earlier era, advanced buildings often were at the bleeding edge of technology. Milestone net-zero energy projects helped to prove viability, refine learning and inspire further advances. "We’re not being guinea pigs anymore," said Calina Ferraro, a principal at Integral Group’s San Diego office, "we’re building taller and more challenging facilities." At one pioneering project, Seattle’s self-powered Bullitt Center, "Our main goal was to be a replicable model," so others could follow in its footsteps, said Jim Hanford, a principal at Miller Hull, which designed the building. To boost its solar potential in cloudy Seattle, the center’s distinctive solar canopy cantilevers out beyond the building’s edges. 

Integration drives innovation. Early successes opened the door to more ambitious building system integration and higher overall performance goals, said John Elliott, chief sustainability officer at Lawrence Berkeley National Laboratory (LBNL). By setting whole-building performance targets — instead of just trying to beat energy codes — LBNL’s newest high-performance building achieves deep efficiency, using a little less than a third of the energy of the facility it replaced. "We integrate the building to a campus-wide operating system and build applications on top of that," Elliott said. "We're seeing a drastic increase in our ability to scale energy management and be much more innovative."

Good enough can still be great. Keep in mind that not every project can hit the high bar of complete electrification — and that’s OK. Whether to score certification or hit a standard, a "kind of tunnel vision" can take over on some projects, Ferraro noted. "Some feel that if we can’t hit that, then we’re going to scrap it." Such perfectionism can derail good-enough approaches that take a step in the right direction and set the stage for greater impact later. For example, quicker upgrades that reduce demand — such as lighting improvements — cut overall building demand load, making electrification easier when it happens.

Incrementalism accelerates retrofits. In fact, step-by-step incrementalism is often the only way existing facilities can be electrified. At San Francisco International Airport (SFO), the challenge of financing upfront conversion costs, questions about technology maturity and the staggered timeline of tenant lease renewals are just a few variables influencing the rollout of the airport’s complex electrification plans across a campus of 103 buildings, according to Amy Nagengast, energy program manager at SFO. 

An audit of its menagerie of hangers, mechanical facilities and passenger spaces is giving SFO a deeper understanding of the challenge ahead. Most of the airport’s energy (56 percent) already comes from electricity; natural gas supplies 44 percent. And of all the buildings using natural gas, four-fifths are tenant-occupied. "We’re really trying to figure out what equipment uses that natural gas," said Nagengast, along with where it’s located, what electric alternatives are available and how best to finance a conversion. The audit is helping SFO sequence a conversion plan for both its own facilities and those occupied by tenants.

Electrifying restaurants is getting easier. SFO found that among its food and beverage tenants, natural gas consumption was concentrated in a short list of kitchen equipment: deep fryers, ovens and ranges. Swaying those restaurants to electrify is as much about education as it is about picking the best alternative gear. 

Once chefs start using electric induction ranges, they tend to like them, said Christopher Galarza, a pro chef who has electrified commercial kitchens and now runs Forward Dining Solutions. But preconceived beliefs can make conversion tough: "Chefs are, by nature, stubborn. We don’t like change." Some of those doubts are founded on past experience, from underpowered '50s-era electric coil stoves to vendors that can’t yet support the latest induction cooktops. 

But today, commercial kitchen suppliers have rolled out a full range of like-sized electric induction gear, which by many measures are better than their gas counterparts. Since electric induction cooktops are so efficient, much less energy is wasted. Food can cook more quickly and more consistently, thanks to more precise temperature control. And because kitchens are cooler overall, staff are less stressed and diners can be brought in closer to the cooking experience. Even skeptical kitchen vets are often "blown away by how this equipment can improve the restaurant experience," Galarza said.

Cooktek commercial induction range

A Cooktek commercial induction range.


About those woks

For all the advantages electric induction offers, development of new cooking equipment has followed a familiar arc. Early commercial induction stovetops and ovens arrived at high prices, beset with occasional performance glitches. Increasing scale is helping suppliers to work out those kinks, improve reliability and drive down costs.

Today, you’ll still find more natural gas cookers in supplier catalogs, but electric induction options are multiplying as prices fall and more chefs and restaurant managers discover their sometimes surprising advantages. Electric induction deep fryers, for example, use about half the oil of gas-heated versions, and the oil can last days longer. 

Woks have been trickier to convert but are tracing a similar path. When placed on a flat induction surface, too little of the wok heats up. The solution? A design that nestles the wok in a concave induction cavity delivers all of the heat — if none of the flame — using a fraction of the energy.

A quick scan of commercial kitchen supply houses shows induction woks remain costly but the price tags are coming down — lately to around $2,000 per station, about twice the price of a conventional pro rig. 

What’s next?

Don’t worry — your favorite stir fry isn’t going away. The parable of the wok illuminates an uneven path ahead for wider electrification. Change is hard and will take time, but it is underway. The technology is increasingly ready, but it will be pricey at first, which can make convincing skeptical stakeholders — from wok hei masters to big property developers — that much tougher. 

For their part, property developers are finding that as the barriers to electrification shrink, priorities are changing. "I would frame it as: What's the cost of not electrifying?" said Becca Rushin, vice president of sustainability and social responsibility at Jamestown, a global real estate investment and management company. "In the grand scheme, the increased costs of electrification ends up being incremental. And you're insulating yourself from the transition risk of being unprepared when legislation is passed."

[Missed VERGE Electrify? Catch up by reading our coverage of the event]

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