NEW YORK — This isn’t the first time Google has been a disruptive agent of change. It is, however, potentially one of the most significant.

The Internet powerhouse’s bold foray into the wireless service business on Wednesday through Project Fi has broad implications for Google itself, for the industry it is about to become a part of and, ultimately, for the consumers who might choose to buy in.

Through partnerships with T-Mobile and Sprint, Google via Project Fi becomes what is known in the wireless industry as an MVNO (Mobile Network Operator). The new phone service promises to leverage the strongest possible network based on a consumer’s location, and intelligently switch from one network to another as need be.

That network could be Wi-Fi, through any one of more than 1 million free public hot spots that Google has deemed kosher. Google says your data will be secure.

It might be Sprint’s 4G LTE cellular network. And it might be T-Mobile’s LTE network. The consumer isn’t supposed to worry about it.

Of course, T-Mobile and Sprint combined are still far behind the dominant U.S. carriers, AT&T and Verizon, the 800-pound gorillas of wireless that Google will now battle.

What’s more, Google will be charging customers only for the data that is used, crediting back money if people consume less data than they paid for.

The basic Project Fi plan costs $20 a month, which buys unlimited talk, text, Wi-Fi tethering and international coverage in more than 120 countries. On top of that, consumers fork over $10 for each gigabyte of data that is used. But as Google explains, if you paid $30 for 3GB monthly but only use, say, 1.4GB of that data in a given month, the company will refund $16.

As it happens, Google isn’t the first to adopt such a concept, but its name-brand recognition ought to bring attention to the practice. Only this week, in fact, Republic Wireless announced that it would refund money to its customers for unused cellular.

“That was a first and it lasted 48 hours. A win is a win,” says Republic Wireless CEO David Morken. The Republic Wireless $10-a-month plan is built around the notion that most calls would be handled via Wi-Fi.

At the outset, Project Fi will work only with a single handset, the fine Motorola-made Nexus 6 phone that starts at $649. Republic’s service works with three Motorola phones, the Moto X, Moto G and Moto E.

“Motorola deserves a shout-out for driving innovation” in both plans, Morken says.

For the consumer, there are obvious questions about how Project Fi will function. Most notably, will the “handoffs” from one network to another prove to be as seamless as Google claims?

As can be expected, Sprint and T-Mobile are publicly embracing the partnership. Sprint spokesman John Votava said in a statement that “Sprint has empowered more than 100 successful MVNOs in the US by delivering a unique combination of a robust nationwide network, differentiated services and operational support and we are proud to enable Google’s entry into the wireless industry as a service provider.”

In a blog post, T-Mobile’s CEO John Legere said, “Project Fi is going to make people think differently about wireless — and I love that.”

But whatever T-Mobile and Sprint gain in the short-run, the wireless business is cutthroat. Have they invited a shark into the fish tank?

Industry analyst Roger Entner of Recon Analytics says Google is “clearly putting pressure on every other mobile carrier, even the ones they’re partnering with. It’s an ecosphere-wide competition, and I think there will be quite a few people currently with Sprint or currently with T-Mobile that would be very interested in it.”

Entner points out that Legere in his blog post made mention of a couple of T-Mobile technologies that will not be part of Project Fi, notably HD Voice, and “next-gen Wi-Fi Calling for seamless handoffs between LTE and Wi-Fi.”

Would-be Project Fi customers will be able to port over their current phone numbers. And Google says folks who request an invite to try the service should hear back within 30 days.