Increasing solar energy use offers key opportunity to reduce US carbon emissions

Increasing solar energy use offers key opportunity to reduce US carbon emissions

by Clarence Oxford

Los Angeles CA (SPX) Aug 01, 2025

A new study led by Harvard T.H. Chan School of Public Health projects that increasing solar power generation in the U.S. by 15% could cut carbon dioxide emissions by 8.54 million metric tons annually. The findings underscore how strategic investments in solar energy can maximize climate benefits depending on the region.

Francesca Dominici, the study’s corresponding author and director of the Harvard Data Science Initiative, said, “This is an exciting study in that it harnesses the power of data science to offer insights to policymakers and stakeholders on how we can achieve CO2 reduction targets.”

The research highlights a stark imbalance in the U.S. energy mix: in 2023, fossil fuels accounted for 60% of electricity generation, while solar contributed just 3.9%, according to the U.S. Energy Administration. Expanding solar could significantly reduce not only CO2 emissions but also the harmful air pollutants responsible for adverse health outcomes, such as fine particulate matter.

The study analyzed hourly electricity generation, demand, and emissions data from the Energy Information Administration over a five-year span starting in mid-2018. Researchers developed a high-resolution statistical model to simulate how added solar generation impacts CO2 emissions both locally and in neighboring regions across 13 U.S. energy zones.

For example, in California, a 15% midday increase in solar output reduced emissions by 147.18 metric tons in the first hour and an additional 16.08 metric tons after eight hours. These delayed reductions had not been quantified in prior studies.

The analysis also identified which regions would benefit most from increased solar capacity. States like California, Florida, Texas, and the Midwest were found to deliver outsized emission cuts per unit of solar investment, while places like New England and Tennessee showed lower returns.

Moreover, regional spillover effects were substantial. A 15% boost in California’s solar production led to daily CO2 reductions of 913 metric tons in the Northwest and 1,942 metric tons in the Southwest, underscoring the importance of interregional collaboration on clean energy deployment.

“Our study offers policymakers and investors a roadmap for targeting solar investments where emissions reductions are most impactful and where solar energy infrastructure can yield the highest returns,” said lead author Arpita Biswas, assistant professor of computer science at Rutgers University. “From a research perspective, our findings also demonstrate the power of harnessing large-scale, high-resolution energy data to generate actionable insights.”

Research Report:Quantifying Effects of Solar Power Adoption on CO2 Emissions Reduction