The idea that buildings should be built with an eye to curbing climate change by making them carbon neutral is being replaced by the development of even more ambitious technologies that aim to remove CO2 from the atmosphere, making them carbon negative. CO2 is the main component of greenhouse gases, which cause global warming.
The Department of Energy is incentivizing work in this field, announcing this week that it is funding 18 projects that will be based on newly developed technologies that can turn buildings into carbon storage structures.
Ten universities and eight national laboratories and private companies have been award winning $39 million to develop clean energy building materials that remove carbon from the atmosphere and demonstrate carbon-negative entire building designs.
The teams, led by DOE’s Advanced Research Projects Agency-Energy (ARPA-E) and selected under the agency’s Harnessing Emissions in Structures Taking Inputs from the Atmosphere (HESTIA) program, will prioritize overcoming obstacles key issue facing carbon-storing buildings: scarcity, expense, and geographically limited building materials.
The 10 universities that received the grants are employing different approaches to extract CO2 from the air: Texas A&M University and the University of Pennsylvania will use 3D printing to their advantage, creating net-carbon-negative building designs with hemp, a lightweight material mixed with the core and lime of the hemp plant and the carbon-absorbing funicular floor systems, respectively. Other universities: Clemson University and the University of Wisconsin-Madison, among other organizations — are planning to create carbon-negative replacements for wood, cement, and insulation.
With projects like these, the program hopes to meet its decarbonization goals by increasing the total amount of carbon stored in buildings, creating “carbon sinks”—which are sites that absorb more carbon than they produce.
While it’s unclear how much carbon the new building materials will absorb, their plant mixes are designed to employ direct air capture, sequestering CO2 from the air and storing it within their layers. For example, at the University of Colorado Boulder, technology under development plans to produce biogenic limestone, which will use coccolithophores, or calcareous microalgae, to absorb and retain CO2 in mineral form through photosynthesis and calcification.
As it currently stands, many buildings around the world are the opposite of carbon sinks. They are “carbon sources”, meaning they release carbon into the atmosphere, making the building and construction sector one of the main producers of greenhouse gases.
Globally, the share of energy-related CO2 emissions from this sector compared to other sectors was 37% in 2020, according to the 2021 Global Buildings and Construction Status Report published by the United Nations Environment Program. In the United States, greenhouse gas emissions produced by the building manufacturing and construction, renovation, and disposal sector account for 10% of total annual emissions.
“There is enormous untapped potential in reinventing building materials and construction techniques as carbon sinks that support a cleaner atmosphere and advance President Biden’s national climate goals,” said US Secretary of Energy, Jennifer M. Granholm. “This is a unique opportunity for researchers to advance clean energy materials to address one of the most difficult sectors to decarbonize that is responsible for about 10% of total annual emissions in the United States.”
The Department of Energy says that greenhouse gas emissions produced by currently used materials are “concentrated at the beginning of a building’s useful life.” This compounds the urgency of addressing national environmental challenges, as the latest report from the United Nations World Meteorological Organization shows that the concentration of three greenhouse gases in particular—carbon dioxide, nitrous oxide, and atmospheric methane—after hitting new highs in 2020.
The ARPA-E announcement is the latest action by the agency to reflect President Biden’s plan to reach zero emissions by 2050.
Earlier this year, ARPA-E also award winning $5 million to fund work by two universities, the University of Washington and the University of California, Davis, to design assessment tools and frameworks to transform buildings into carbon storage structures.
HESTIA was created in 2021 to develop building materials and designs that specifically remove carbon during the building production process and store it in the chemical structure of the finished product.