One of the biggest energy stories of last year was the challenge of powering the artificial intelligence boom.

Tech companies are putting serious money behind renewables and nuclear on the assumption electricity consumption will soar. But in the immediate future, natural gas is expected to meet the lion’s share of additional demand.

Gas-fired power is a tried and tested technology that’s the backbone of the US energy supply. Yet developers of new plants face a rude awakening, and it’s a matter of costs.

The industry rule of thumb is that combined-cycle gas turbine technology costs about $1 billion per gigawatt to build — an estimate that’s become severely outdated.

The next wave of these workhorses, which can provide power around the clock and help back up renewables, will require about $1.5 billion to $2 billion per gigawatt, said Julien Dumoulin-Smith, an analyst at Jefferies LLC.

Inflation has driven up bills for turbines, labor and construction. Waiting times are also blowing out — to about three years for 200-megawatt turbines, according to recent Siemens Energy AG estimates. GE Vernova Inc. is booking orders for 2028 and beyond.

“This power cycle is going to be longer and more protracted and likely higher-priced than ever,” Dumoulin-Smith said. “You have to be sober about what’s going to get done.”

Sticker shock hasn’t hit the industry just yet, simply because little gas capacity has been built since the height of the shale boom. Growth has leaned more toward renewables such as solar and battery storage.

But burgeoning consumption by data centers is likely to see demand for gas-fueled electricity climb, and developers need to be clear-eyed about prices and lead times, according to Kushal Patel, a senior partner at Energy & Environmental Economics Inc.

“Even if you have a bajillion dollars to spend,” he said, “it’s going to take time.”