Power company ERock, which makes modular gas-fired power units used by artificial intelligence data centers, was enjoying a much-needed jolt to power companies Tuesday.

Shares of the Houston-based firm, which began trading publicly in June, closed up 10%. That is nearly as much as the rise for Constellation Energy, which closed up more than 12% after announcing a deal with Alphabet-owned Google that will enable it to dramatically increase the amount of power it will produce.

The Constellation deal "was a positive read for the speed to power thematic and highlighted the urgency from hyperscalers to get deals done," Evercore analyst Nick Amicucci told Barron's.

Power -- or more specifically, a shortage of it -- has been a key worry as the demand from AI is set to rise dramatically in the coming years. The Constellation announcement is a win not just for hyperscalers but also for consumers as it also promises to add more electricity to the grid, which in turn will keep retail prices in check.

Shares of ERock have languished since its June 10 debut, when it began trading at $20.10. Even with today's rise, the stock is down 32% since then on concerns about its ability to convert announced deals into finalized projects.

The company reported in August that it had a contracted sales backlog of $1.7 billion. It announced a recent order from Anthropic for its power systems and has a deal with Meta for on-site power generation using its modular systems.