As wind and solar power expand rapidly worldwide, researchers are confronting a growing challenge: how to effectively integrate them into the power grid.
Wind turbines and solar panels have what economists call zero marginal cost, meaning producing additional units of electricity requires no fuel once installed. At the same time, this renewable energy varies greatly with the weather and can create operational challenges for grid operators.
A new review study from Georgia Tech examines how these characteristics are reshaping electricity markets and grid operations - and why addressing the challenge requires cross-disciplinary collaboration.
The study, published in Renewable and Sustainable Energy Reviews, synthesizes more than a decade of research. It analyzes over 200 studies on the engineering, economic, and policy implications of managing renewable energy sources that are both intermittent and effectively zero-cost to operate.
"Wind and solar are now among the lowest-cost sources of electricity in many parts of the world, but integrating them into the grid isn't simple," said Matthew Oliver, associate professor in the School of Economics and lead author of the study. "The wind doesn't always blow, and the sun isn't always shining, so output can fluctuate significantly, which complicates grid management."
He added, "Historically, variation in electricity systems generally came from the demand side, and operators could simply ramp generation up or down. Now, we have variability on both supply and demand sides."
Analyzing the Data
Looking at the problem, Oliver knew he would need to be familiar with engineering concepts to get at the heart of the issue. He created a research team with Daniel Matisoff, professor in the Jimmy and Rosalynn Carter School of Public Policy; Santiago Grijalva, professor in the School of Electrical and Computer Engineering; and graduate student co-authors Maghfira Ramadhani (economics), Oliver Chapman (public policy), and Amanda West (electrical and computer engineering).
Analyzing over 200 studies published since 2010, the team mapped the complex interactions between electricity market design, grid operations, and renewable technologies.
They also explored the economic implications of large amounts of zero-marginal-cost electricity entering wholesale electricity markets. Because wind and solar have very low operating costs, they can lower prices in wholesale electricity markets. That benefits consumers, but it can also make it harder for flexible conventional plants to earn enough revenue to stay available when renewable output falls.
Collaborating Across Disciplines
The team argues that successfully scaling renewable energy will depend on collaboration across traditionally separate fields.
"Engineering constraints affect how electricity markets work, markets influence investment decisions, and policy shapes how those investments happen," Oliver said. "When it comes to complex topics like this, you can't really treat engineering, economics, and policy as separate problems. They're all part of the same system."
The researchers found that electricity systems with high shares of renewable energy will require coordinated solutions that combine improved engineering practices, market reforms that value flexibility and reliability, and policies that align private investment with long-term decarbonization goals.
"Our hope is that this paper helps researchers across disciplines communicate more effectively," Oliver said. "If we want electricity systems with high levels of renewable energy to work reliably, then engineers, economists, and policymakers all have to understand how their decisions affect the others."
Citation: Oliver, Matthew E., et al. "Managing Zero-marginal-cost, intermittent renewable energy: A survey of the engineering, economic, and Policy Challenges." Renewable and Sustainable Energy Reviews, vol. 226, Jan. 2026.
