A new study led by the **T.H. Chan School of Public Health at Harvard** reveals that increasing **solar energy generation** by 15% in the **United States** could annually reduce **8.54 million metric tons of carbon dioxide (CO2)**.
The research, published in the journal **Science Advances**, provides a detailed look at **where and how to invest in solar energy** to maximize [its climate benefits](https://noticiasambientales.com/energia/japon-revoluciona-la-energia-solar-con-un-superpanel-su-potencia-equivale-a-unos-20-reactores-nucleares/).
## Solar Energy vs. Fossil Fuels
According to data from the **US Energy Administration**, in 2023:
– **60% of electricity** was generated by **fossil fuels**
– Only **3.9% came from solar energy**
Burning fossil fuels not only emits **CO2** but also **atmospheric pollutants** such as **fine particulate matter**, linked to [respiratory diseases, hospitalizations, and premature deaths](https://noticiasambientales.com/ciencia/advierten-que-de-cada-3-personas-1-respira-aire-contaminado/). The expansion of solar energy could **mitigate these impacts** and **improve public health**.
## A Statistical Model to Measure Regional Impacts
The scientific team examined **five years of hourly data** from July 2018, covering 13 regions:
– California, Florida, Texas, Midwest, Mid-Atlantic, Southwest, Southeast, New England, New York, Carolinas, Tennessee, Northwest, and Central Region
Using an **advanced statistical model**, they evaluated how **hourly increases in solar generation** affect **CO2 emissions** in each region and its neighbors.

## Immediate and Deferred CO2 Reductions
The study quantified for the first time **immediate and deferred CO2 reductions**. For example, in **California**:
– A 15% increase in solar generation at noon reduced **147.18 metric tons of CO₂ in the first hour**
– Eight hours later, the reduction was **16.08 metric tons**
This approach allows for a better understanding of the **systemic effects** of solar energy in real-time.
## Regions with the Highest Climate Return
Researchers identified areas where **small increases in solar energy** generate **significant climate benefits**:
– **High impact**: California, Florida, Mid-Atlantic, Midwest, Texas, Southwest
– **Limited impact**: New England, Central Region, Tennessee
This allows for **prioritizing investments** in regions with the **highest environmental return**.
## Positive Side Effects in Neighboring Regions
**Solar expansion in one area can reduce emissions in others**
The study also highlights the **indirect benefits** of solar energy. For instance, a 15% increase in solar capacity in **California** was associated with reductions of:
– **913 metric tons of CO2 per day in the Northwest**
– **1,942 metric tons per day in the Southwest**
This underscores the need for **regional coordination in clean energy policies**.
## Data Science Serving Energy Transition
“This study demonstrates how data science can guide strategic decisions to achieve CO2 reduction goals,” noted **Francesca Dominici**, director of the **Harvard Data Science Initiative**.
The research provides **concrete evidence** for **public policy makers, investors, and communities** to **prioritize climate actions** based on science.



