The world’s leading company capturing carbon dioxide from the atmosphere is opting not to partner with oil and gas companies, in contrast with its top competitors.

“Given the product that we are offering, being independent of the interests of a specific industry is very important, and not only that, it’s core to our strategy,” said Jan Wurzbacher, co-founder of Switzerland-based Climeworks, in Cipher’s latest “Innovators” virtual interview.

Watch the full interview with Wurzbacher here.

The other two leading direct air capture (DAC) companies have partnerships with and/or investments from oil companies: U.S.-based Global Thermostat with ExxonMobil and Canada-based Carbon Engineering with Occidental Petroleum and Chevron.

Wurzbacher is touching on a dicey debate.

The oil and gas industry faces criticism over its decades-long role fighting action on climate change, but more recently some companies have begun taking significant steps toward supporting new technologies, including DAC and renewable electricity.

To further complicate matters, some oil companies are using captured carbon to extract more oil, raising concerns about the climate benefits.

“I’m sure that the [oil] industry has to and will play a role,” said Wurzbacher. The industry’s engineering and geology expertise is vital when applied to capturing and storing carbon.

But he added: “For the moment, drilling for oil and gas is still quite an economically attractive business, and we need to make sure that we clearly separate between these two.”

Our conversation took place in mid-May, just a few weeks after the company raised $650 million in funding to build more and bigger plants in various parts of the world, the largest amount ever for a startup in this space.

Climeworks has a long and diverse list of investors raising a total of more than $800 million since its 2009 founding, including the most recent round led by private equity firm Partners Group and GIC, Singapore’s sovereign wealth fund. It doesn’t have any oil and gas investors.

Another reason oil and gas companies face scrutiny is concern that investing in DAC gives the industry a pass to avoid cutting emissions.

Wurzbacher says that’s a false choice: “We just need to do both.”

Climeworks began operating the world’s largest DAC facility last year in Iceland with a capacity of 4,000 metric tons of carbon.

Numerous startups are pursuing different technologies to capture CO2, but Global Thermostat and Carbon Engineering are the only others capturing any amount of carbon right now, and their current levels are tiny compared to those of Climeworks, according to the International Energy Agency.

Yet Climeworks’ 4,000 tons are tiny compared to what’s needed. Human activity emits 51 billion tons of greenhouse gases a year. To qualify for U.S. government funding in the infrastructure law, a company’s facility must capture at least 1 million tons of carbon a year.

“Going to the United States is something that’s on the table now,” Wruzbacher said. He cited an Energy Department program that is directing $3.5 billion into regional DAC hubs, networks of facilities and infrastructure for capturing CO2.

“There are several challenges to overcome” in the U.S., said Wurzbacher, including ensuring an ample supply of renewable energy for the large amounts of electricity and heat the company’s technology needs. Finding suitable underground conditions to store carbon and transporting it are other hurdles.

Iceland, with its ample supply of clean geothermal energy and underground rock suitable for storing CO2, is “a low-hanging fruit,” Wurzbacher said. “Up until 2030, the art will be in finding the other low-hanging fruits.”

Cost is a formidable challenge facing Climeworks and all carbon removal companies largely because captured carbon currently has little intrinsic economic value.

A benchmark cost per ton at its Iceland plant is around $800, according to a Climeworks spokesperson. Wurzbacher said they’re likely to get that down to $300/ton or lower by the end of the decade. That’s triple the U.S. Energy Department goal of $100 by decade’s end.

Unlike some other DAC companies and other big-infrastructure companies, including oil producers, that aim to lower costs by going big, Climeworks is going the opposite way.

“A fundamental basis of our technology concept is building modular systems that can be mass manufactured,” Wurzbacher said. “That is the principle that made solar PV [photovoltaic] the cheapest energy source we have today on the planet.”

The Climeworks team calls their modular systems CO2 collectors, which are about the size of a cargo shipping container. The most prominent visual part of the machine are massive fans. (See this week’s photo).

Here’s a (very) simple explanation of their technology: The fans draw the air in, CO2 is captured on the surface of a filter inside the machine, and then it’s separated from the filter using low-grade heat. The carbon is further treated and injected deep underground where it’s turned to stone.

The whole process requires a lot of energy, which Climeworks says will always be powered by clean resources. That all makes it harder to lower costs.

“By using a modular system, we can do very fast iterations of our technology,” Wurzbacher said.

Editor’s note: Carbon Engineering’s investors include Bill Gates, founder of Breakthrough Energy, which supports Cipher.