How US states can use solar to meet their climate targets

In my role as a consultant and modeler at SSG, I sometimes encounter skepticism towards the feasibility and viability of renewable energy to meet our energy needs. Does renewable energy provide a viable path for the US states to meet their emissions reduction targets?

Absolutely, but it’s complicated. When I collaborated on research to investigate this issue, I found that a massive integration of solar energy across the electrical grid can support some states in achieving their greenhouse gas emissions reduction targets. The study, which was recently published in the journal Energies, found that California, Arizona, New Mexico, and part of Nevada can achieve state greenhouse gas emission reduction goals by exclusively shifting to solar energy. In less sunny regions, such as New York and the six states that comprise New England, solar energy has a smaller impact on emissions. Even so, it can play an important role in diversifying the energy supply and improving resilience to extreme weather and other impacts of climate change.

Drawing on hourly energy use data from the US Department of Energy, my collaborators and I assessed how much energy use could be supplied by integrating solar power facilities into the California, New England, New York, and the Southwest power grids to meet each region’s hourly energy needs throughout a full year. Then, we quantified potential reductions in carbon emissions resulting from the integration of solar power facilities in these regions. We also explored how varying levels of solar energy adoption across these regions could help meet state greenhouse gas reduction goals.

The findings underscore that solar energy can play a central role in decarbonizing sunny states like California, Arizona, New Mexico, and Nevada. To capitalize on it, policymakers can enhance solar-focused initiatives and incorporate them into state energy strategies.

California has successfully boosted solar adoption by  implementing financial incentives, such as tax credits, rebates, and net-metering policies, to make rooftop solar more attractive and affordable for residential, commercial, and industrial buildings. Local and state governments in Arizona, New Mexico, and Nevada could replicate California’s success with similar policies to accelerate progress toward their emission reduction targets. At the same time, these states should not rely solely on solar for their energy needs: this could lead to energy shortages during periods of low sunlight. To build a reliable and resilient energy system, policies should promote a balanced mix of renewable resources, along with energy storage.

In cloudier regions like New York and New England, solar energy can still serve as an integral component of a comprehensive energy strategy to diversify energy sources and enhance grid resilience. In these states, encouraging decentralized smaller scale installations of solar systems such as community solar projects allows solar to contribute to the energy supply efficiently, even with variable weather conditions. In addition to reducing reliance on fossil fuels and, by extension, greenhouse gas emissions, solar projects enhance energy resilience by providing backup during power outages.

Since this study was conducted, the cost of solar has continued to decrease. This means the integration of solar energy production outlined in this study is even more affordable.

The bottom line: Policies and incentives that support solar energy can significantly contribute to the US energy transition away from fossil fuels, even in states with gloomier weather.

Esteban Soto (he/him/el) is an energy systems modeling specialist at SSG, where he analyzes energy processes and emissions and advocates for integration of innovative technologies. Esteban advances hourly energy modeling, a crucial approach that significantly improves the integration and efficiency of renewable energy systems. He became interested in renewable energy when he joined a team to design and build a solar car as an undergraduate engineering student.