When it comes to cutting carbon emissions, a renewable power grid and electric vehicles are the big-ticket items. But buildings, which produce about 40 percent of global carbon emissions, are also a key part of the transition to net-zero emissions.
According to a new study, the U.S. has the potential to cut building emissions by 91 percent compared to 2005 levels. That could save the country over $100 billion per year on energy costs, researchers from Lawrence Berkeley National Laboratory report in the study published in One Earth.
Around 28 percent of global carbon emissions from commercial and residential buildings come from operating them: from the energy needed to heat, cool and power them. The remaining comes from the materials and construction.
In 2005, the US building sector produced 2,327 million tons of carbon dioxide, a record for high emissions. Emissions have since declined by 25 percent, and are projected to keep declining by up to another 41 percent by 2050. In the first half of 2023, for instance, largely due to a shift away from coal-generated electricity, U.S. building sector operating emissions fell by over 8 percent in—almost 80 million metric tons of carbon dioxide—compared to the same time last year, according to U.S. Energy Information Administration.
But we will need to keep cutting emissions to reach 2050 net-zero emissions goals, the authors say. And that will require going beyond switching to renewable electricity, write Jared Langevin and colleagues in their new paper.
The researchers define three main approaches to reducing the carbon footprint of buildings: improving energy efficiency with things like high-performance windows; converting services such as space and water heating to efficient, low-carbon electric sources such as electric heat pumps; and technologies such as smart thermostats and connected appliances that impact how and when power is drawn from the grid.
The Berkeley team modeled building energy demand, carbon emissions, and costs through 2050 under three different scenarios—low, moderate and aggressive—of the three emissions-reducing approaches. The aggressive scenario could cut emissions by 91 percent over 2005 peak levels, they found.
Nearly half of the yearly emissions reductions are from efficiency and electrification. “Demand-side measures” that increase power grid flexibility, like heat pumps and smart thermostats, could contribute up to 45 percent of the emissions cuts.
The authors say that the aggressive scenario could lead to annual energy cost savings of around $107 billion by 2050. That could help balance out the cost to decarbonize the electrical grid.
“There are no ‘silver bullet’ solutions for building decarbonization,” they write. “Achieving deeper levels of emissions reductions…will require a comprehensive mix of solutions addressing both the generation and end uses of energy.”
Source: Jared Langevin et al. Demand-side solutions in the US building sector could achieve deep emissions reductions and avoid over $100 billion in power sector costs. One Earth, 2023.