A new home in the Bahamas was built using alternative concrete that absorbs carbon dioxide from the air. It’s a house that’s supposed to help fight climate change, and the plan is to build 999 more like it.
That’s the goal Rick Fox, the NBA Lakers legend turned actor, is now working toward in the small island nation where he grew up. Fox is the CEO and co-founder of sustainable building materials startup Partanna, which unveiled its first home today. If they succeed in the Bahamas, the goal is to make alternative concrete an everyday building material that can reduce pollution from construction.
“I ended my entire career that I had spent in Hollywood pursuing and creating [climate] Fox says the edge. “I had to navigate an industry that was new to me and meet people who were looking at me and saying, ‘What the hell are you doing in concrete?’”
“What the hell are you doing with concrete?”
Concrete happens to be a major source of greenhouse gas emissions that cause more severe storms, wildfires and other disasters through climate change. The reason is actually cement, which is a major component in concrete and alone is responsible for more than that 8 percent of carbon dioxide emissions worldwide.
“My entry into the world of concrete was just an attempt to survive the need for innovation in my home country,” says Fox. Hurricane Dorian struck the Bahamas in 2019, destroying 75 percent of homes on hard-hit Abaco Island and displacing thousands of people. Fox was in Los Angeles at the time. “The closest thing I can do is race with CNN to shout from the rooftops that we need to do something better,” he says.
Soon after, he met California-based architect Sam Marshall, whose home was damaged in the 2018 Woolsey Fire, one of the most destructive fires in the state’s history. Marshall had “actually been struck by lightning in a bottle,” according to Fox. Working with materials scientists, they were able to develop a way to make concrete without using carbon-intensive cement. Together they co-founded Partana.
The two are tight-lipped about the process, but the main ingredients are brine from desalination plants and a byproduct of steel production called slag. By eliminating cement as an ingredient, Bartana can avoid the carbon dioxide emissions that come with it. Cement manufacturing produces a lot of climate pollution because it must be heated to high temperatures in a kiln and because it triggers a chemical reaction that releases additional carbon dioxide from the limestone.
Bartana says his mixture can be processed at ambient temperatures, so it doesn’t need to use a lot of energy. It also says that the binding components in the mixture absorb carbon dioxide from the air and trap it in the material. In a home or building, the material continues to pull in carbon dioxide. Even if this structure is demolished, the material retains carbon dioxide and can be reused as aggregate to make more replacement concrete.
This is how a startup can call its material and newly constructed house “carbon negative.” The 1,250-square-foot structure is supposed to capture up to 5,200 mature trees’ carbon dioxide per year.
Calculating carbon using trees is certainly difficult. a guardian investigation Earlier this year, it found that 90 percent of rainforest offsets approved by one of the world’s leading carbon credit certifiers, Vera, were “worthless” because they likely did not lead to actual pollution reductions. Verra also certifies carbon credits for Partanna. Fox says the amounts of carbon dioxide captured by Bartana are easier to measure than forest offsets and are not as vulnerable as forests that need to be protected from deforestation in order to store carbon.
It is also worth noting that the main components of the Bartana plant, slag and brine, come from energy-intensive steel and desalination facilities that can produce a lot of carbon dioxide emissions on their own. Partana does not count those emissions in its carbon footprint. “This is not on us…this is waste that we take and use for good,” Fox says.
“It’s good that they’re making use of waste,” says Dwarak Ravikumar, an assistant professor in the School of Sustainable Engineering and Built Environment at Arizona State University. However, Ravikumar says, “We need to do a robust analysis of this from a systems perspective to understand the overall climate impact.” He says it’s important for the company to share its data so researchers can assess Bartana’s full ecological footprint and the scalability of its strategy.
“We are not just on the front line of climate change; we are on the front lines of solutions.
Fox isn’t alone in its mission to make building materials more sustainable than traditional concrete. Microsoft announced last month that it is testing low-carbon concrete for its data centers. Other startups are working on taking carbon dioxide out of the atmosphere and trapping it in concrete.
Bartana says it has an advantage because its material is made from brine. It should actually become stronger with exposure to seawater, an attractive trait for a country made up of many low-lying islands vulnerable to storm surge and sea level rise.
“We are not only on the front line of climate change; we are on the front lines of solutions,” Philip Davis, Prime Minister and Minister of Finance of The Bahamas, said in a press release in Bartana.
The Bahamas government is collaborating with Bartana to build 1,000 homes, starting with a community of 29 more homes that are supposed to be built by next year. No one lives in Nassau’s First District yet; It’s a prototype. But the next one is expected to be part of a program to help first-time homeowners.