The lights are back on and the drinking water restored in most of Texas. Plumbers are fixing the pipes that burst in frigid, blacked out homes.
Our state’s leaders will need years to fix what went wrong in our epic failure, which featured 500 times as many forced blackouts as California’s wildfires last summer. But national attention will fade if other Americans misinterpret last week’s blackouts as a uniquely Texan failure.
In some ways, they were. Only Texas runs its power grid as an island, isolated from the two larger grids that cover most of the United States and Canada. That left Texas stranded when the Arctic blast slammed through. Other states restored power with imports from their neighbors. Our isolated grid also shielded Texas companies from federal regulators who may have forced them to better prepare for storms.
Although these uniquely Texan traits exacerbated our crisis, the blackouts revealed a broader vulnerability of power systems nationwide that have grown overly reliant on gas.
Gas has been touted as a “bridge fuel” from coal to renewable energy. It’s called a “firm” resource, available whenever we need it. But last week’s failures revealed the bridge to be less firm than we thought. That heightens the urgency of crossing the gas bridge and constructing more resilient systems beyond it.
Behind the bridge lie legacy systems built upon “baseload” power sources — coal, nuclear and hydropower. Each of those sources can fail for distinct reasons.
Coal plants fail when droughts dry up their water supply, equipment malfunctions or coal piles become frozen or waterlogged. Even when they work, coal plants emit deadly and planet-warming pollution, poison watersheds nearby and require mines that devastate ecosystems far away.
Nuclear plants falter when their water supply evaporates in the heat or freezes in the cold, as it did at one Texas plant last week. Hydropower depends on rainfall, which is becoming more variable with climate change.
Every baseload source is shrinking nationwide, outcompeted by cheaper sources even as electricity demand is expected to grow for electric cars and other purposes.
That’s left gas filling the void. Gas supplies 46 percent of electricity on the main Texas grid and nearly 40 percent nationally, dwarfing any other source. Power systems lean even more heavily on gas when demand peaks, since its output is more flexible than other sources. The failure of gas to carry that weight drove our blackouts last week.
Gas has its advantages. It’s cleaner than coal, especially if methane leaks are captured. It’s cheaper than nuclear. It can be deployed where there aren’t rivers to dam. Its output is reliable most of the year.
But gas has its own unique vulnerability. Only gas electricity depends on a continuous supply of fuel, piped across hundreds of miles. If that supply falters, as it did last week, there’s no coal pile, nuclear fuel rods or water reservoir on hand to back-up its supply.
What’s worse, gas and electricity are uniquely vulnerable to each other. We use gas to make electricity and electricity to move gas. When either one falters, it can knock down the other. Compounding the problem, demand for gas and electricity both peak at the hottest and coldest times of the year.
As we race across it toward a cleaner future, we must bolster our gas bridge. Millions of people can’t be left in the dark when the next Arctic blast hits. That means gas supply systems and power plants must be weatherized to withstand extreme conditions.
But gas can’t be a forever bridge. Fossil resources are inherently finite. Their emissions poison our lungs and warm our planet. That’s exacerbating extreme events that threaten our energy systems throughout the year.
The faster we can cross the gas bridge, the more quickly we can build the power systems of the future. Those systems will rely upon wind and solar power, supplemented by some mix of nuclear, hydropower, geothermal and cleanly burned gases. They must feature more robust transmission and storage to keep supply reliable throughout the year. Efficiency must rein in demand.
Built right, future power systems can provide electricity more cleanly, reliably, affordably and resiliently than the baseload systems of the past or the gas bridges of today. Last week’s collapse shows us we must protect our fragile bridges and race across them to the cleaner power systems of tomorrow.
Daniel Cohan is an associate professor of civil and environmental engineering at Rice University.