Power under pressure: Auburn Engineering professor explains how summer heat strains the grid
Published: Jul 8, 2025 2:00 PM
By Joe McAdory
When a recent Yahoo News headline warned that “Extreme Heat Is Straining the U.S. Power Grid,” it echoed what many across the country have already experienced firsthand: flickering lights, skyrocketing energy bills and the uneasy hum of an air conditioning unit pushing to keep up.
What happens to power systems during extreme heat? Are blackouts inevitable as weather patterns intensify? What changes, if any, can help?
Eduard Muljadi, the Danaher Professor in the Department of Electrical and Computer Engineering, specializes in power systems resilience and shared his insights.
How do heat waves impact electricity demand and grid infrastructure?
Eduard Muljadi: When heat waves hit, electricity demand spikes—mainly because air conditioning units run harder and longer, not just in homes but in businesses and data centers. That increase puts a strain on the grid, particularly during peak hours in the late afternoon and early evening. At the same time, the grid’s infrastructure, especially transmission lines and transformers, is stressed by the heat itself. These components can overheat, lose efficiency and become more prone to failure. On the generation side, thermal power plants may have to reduce output because water supplies used for cooling are either too warm or too limited. Even renewables like solar and wind can see drops in performance during extreme heat, which further tightens the supply-demand balance.
What kinds of failures or bottlenecks are most likely during high-demand heat events?
Eduard Muljadi: It’s a combination of mechanical stress and mismatched supply. Transformers and substations can overheat after hours of sustained load, which leads to insulation breakdown or failure. Overhead lines can sag when they get hot, and if they contact vegetation, that can cause fires or outages. Underground cables face similar thermal expansion problems. Generation also suffers — thermal plants rely on cool water, and when it’s too warm or unavailable, output drops. Solar panels become less efficient at high temperatures. If generation can’t meet demand, you start to see voltage and frequency instability, which can lead to brownouts or rolling blackouts. Add to that outdated infrastructure and operational challenges — like forecasting errors or lack of regional coordination — and the system becomes extremely vulnerable.
Are blackouts inevitable in a hotter future, or can we engineer our way around that scenario?
Eduard Muljadi: Blackouts aren’t inevitable in a hotter future, but avoiding them requires bold engineering, smart policy and sustained investment. Without action, rising temperatures and demand will strain the grid beyond its limits. Modernizing infrastructure is key. Upgrading transmission lines with heat-resistant materials, reinforcing substations and deploying real-time monitoring can prevent failures. Upgrading overhead lines to underground lines and enhancing cooling systems also reduces heat-related risks. Expanding grid flexibility is equally vital. Utility-scale batteries, smart grid technologies and distributed energy resources like rooftop solar and storage can balance supply and demand. Virtual power plants and long-distance transmission lines improve resilience. Managing demand helps, too. Programs that shift usage away from peak hours, energy-efficient buildings and updated building codes reduce stress on the system. Time-of-use pricing can guide consumer behavior. Finally, supportive policies like streamlined permitting, market reforms and regional coordination are essential. With the right tools and commitment, we can engineer a future where blackouts are the exception, not the rule.
Are some types of power sources more resistant to extreme heat than others?
Eduard Muljadi: Yes, and it’s important to understand those differences. Traditional thermal power plants — coal, gas and nuclear — are very sensitive to heat because they need water for cooling. During a heat wave or drought, their output often drops. Solar panels produce less power as they heat up, sometimes losing up to 15 percent of their efficiency. Wind is more mixed. Hot air is less dense, which reduces power generation, but wind patterns vary. Hydropower is fairly heat-resilient but depends on water availability. Batteries are sensitive to temperature, too, but most are designed with thermal controls. The key takeaway is that no one source is immune to heat, which is why having a diverse mix and strong backup systems is crucial.
Are aging transformers and substations the weak link, or are transmission constraints more pressing?
Eduard Muljadi: It’s not one or the other — it’s both, and they’re interconnected. Many of our transformers and substations are operating well past their intended lifespan. They can’t dissipate heat as effectively under high loads, which leads to breakdowns. At the same time, transmission lines face their own limits. When lines heat up, resistance increases, and they sag sometimes dangerously close to vegetation. To prevent fires or damage, operators reduce how much power those lines can carry. That creates bottlenecks, especially when you’re trying to move electricity from one region to another. So, you’ve got aging equipment on one end, and limited flexibility on the other. Repairing one without the other doesn’t solve the problem.
What kinds of grid upgrades or policies are urgently needed to prepare for future extreme heat?
Eduard Muljadi: We need to build a grid that’s smarter, stronger and more flexible. That means investing in large-scale battery storage, improving transmission lines so they can handle higher loads and modernizing substations with better cooling systems and monitoring tools. Smart grid technologies like real-time metering and automated fault detection can make the system more responsive. On the policy side, we need faster permitting for new infrastructure, incentives for utilities to modernize and stronger demand-response programs. Updating building codes to improve insulation and reduce cooling needs is also key. On a broader level, regional coordination and domestic manufacturing of critical components will help build resilience across the board. We need a rapid and coordinated transformation because the risks are growing faster than we’re currently responding.
What can residents do to prepare or even help reduce the threat of grid failure?
Eduard Muljadi: People can make a big difference. During heat waves, the best thing to do is reduce energy use during peak hours — typically from 3 to 9 p.m. Raise your thermostat to 78 degrees, use fans, avoid using ovens and shift things like laundry or EV charging to early morning or late evening. Close blinds to block heat and unplug devices you’re not using. It’s also wise to prepare for outages — have flashlights, water, batteries and know where the nearest cooling center is. If you have a generator, use it safely. Finally, support longer-term resilience by joining utility programs, staying informed and — if it’s possible for your household — installing solar with battery storage. Every bit of local generation and conservation helps relieve pressure on the broader system.
Media Contact: , jem0040@auburn.edu, 334.844.3447
What happens to power systems during extreme heat? Are blackouts inevitable as climate change intensifies? What can help? Eduard Muljadi answers these questions and more.
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