A version of this article first appeared in the CNBC Property Play newsletter with Diana Olick. Property Play covers new and evolving opportunities for the real estate investor, from individuals to venture capitalists, private equity funds, family offices, institutional investors and large public companies. Sign up to receive future editions, straight to your inbox. Even as more local communities rise up against the proliferation of massive, energy- and water-sucking data centers, some big players in housing are betting consumers would be willing to put mini data centers right on the walls of their homes. Span is a California-based startup that originally launched with so-called "smart" electrical panels designed to help homeowners save money on their electric bills. Now, with the help of Nvidia, it has come up with something new – small, fractional data centers, or "nodes," called XFRA units, that can be put on the side of residential homes and small commercial businesses. The idea is to take advantage of unused electrical capacity on local grids, which the Span smart panels can pinpoint. The rapid growth of artificial intelligence has strained local power grids nationwide and, in some cases, resulted in higher electric bills for homeowners. A network of these nodes, communicating with each other across the country, is the equivalent of a small to mid-sized traditional data center, which could either augment an existing center or negate the need to build a new one, Span says. Hyperscalers and AI cloud providers just tap into the network as they would a traditional data center. "Fundamentally, it's an infrastructure play," said Arch Rao, founder and CEO of Span. "We're uniquely positioned to build infrastructure that can simultaneously help us meet what is clearly an insatiable demand for more compute, much more cost effectively, while benefiting individual consumers." The small, white XFRA boxes with the hardware inside are put on the outside of homes, alongside regular HVAC and electrical systems. Span says it can install 8,000 XFRA units about 6 times faster and at 5 times lower cost than the construction of a typical centralized 100 megawatt data center of the same size. Span collaborated with Nvidia, using its technology in the system, including one of the first-to-market uses of liquid-cooled Nvidia RTX PRO 6000 Blackwell Server Edition GPUs. These require no fans, so there is no noise. "We're trying to get access to power, and there's a lot of power right now on the grid. But, unfortunately, to come up with large loads for big data centers – it's a challenge," said Marc Spieler, senior managing director of global energy industry at Nvidia. "The ability to leverage existing locations that have access to power makes a lot of sense. … We believe that we can bring on AI solutions quicker, and it should add to the affordability story." The Span systems include its smart electrical panel, the XFRA unit, a home backup battery and, in some cases, solar panels. The panels tap into existing, unused electrical capacity, which then powers the XFRA system. Homeowners would pay a flat fee for both electricity and Wi-Fi. "If you are one of the homes that is hosting an XFRA node, XFRA will then give you compensation for energy and internet usage," Rao said. "We expect that the value there is a heavily discounted cost of energy and internet." The Span systems are going on newly built homes. PulteGroup, one of the nation's largest homebuilders, is in the early testing phase as it assesses the capabilities and economics of the XFRA nodes, according to a company spokesperson. It has already been deployed in a handful of communities. "There is certainly opportunity, as SPAN can provide homeowners with access to innovative technology and potential income generation that can help offset monthly energy costs," the spokesperson said in a statement. "On a larger scale, if the technology proves out, it might also keep local infrastructure from being overburdened which could keep land open for other uses, such as building homes."