A new data center in southwest Texas isn’t connected to the grid—but it also didn’t require building any new power plants. Instead, a startup called Rune used modular technology to plug in directly at a solar farm, running on solar power that would otherwise be wasted.
The company, which just raised a $40 million Series A round of funding led by Spark Capital, says that its model can be replicated at solar plants around the country, giving data centers access to clean power faster and cheaper than building new power capacity.
“We’re the fastest time to compute,” says Rune’s CEO, William Layden. “We don’t need to wait three years, four years, five years for new infrastructure to get built. We’re using what we have today to bring on compute today.”
Rune taps solar power that the grid can’t use
A typical solar plant wastes as much as 20% of the energy that it generates, the company says. There’s often so much extra solar power in the middle of the day that grids can’t make use of it. The California grid, for example, wasted around 3.5 million megawatt-hours of solar in 2025, an amount that could have powered hundreds of thousands of homes. Solar power plants also waste power when transformers or other equipment are offline.
Some of that extra power can be stored in large-scale batteries. But Rune says it also makes sense to tap into it directly. The company’s modules, called RELIC (renewable energy linked intelligent compute), house servers, cooling equipment, and custom power electronics that connect the solar panels to the computers.
“Solar produces direct current electricity; computers run on direct current electricity,” says Layden. “Nothing connected them before Rune.” Because the system runs on DC power—safely converting the high-voltage electricity from solar into the right voltage—it doesn’t need traditional transformers, equipment that currently faces shortages. “Our supply chain is radically simpler and actually more robust,” he says.
The system is also much faster to build. It avoids the supply chain challenges that other approaches face, including gas power plants, which can face four-year delays for transformers. It also doesn’t have to deal with the long process of grid interconnection and permitting, or community opposition to building new power plants. Essentially no construction is needed; the company just places its 8-by-8-foot modules on site using a forklift.
The company spent two years designing the modules to be as simple as possible to install. The data center in Texas, with 50 modules and 1 megawatt of capacity, took only an hour to put in place.
For Rune, the future of data centers looks more like manufacturing than construction
Data centers are typically seen as construction projects. Rune thinks of itself as a manufacturing business, instead, churning out standardized modules that can quickly be added at any renewable power plant.
The company owns and operates the modules itself, and then partners with solar farms—and soon, wind farms—to capture their excess power. Then, like other data centers, it sells computing capacity to customers. The company’s whole approach saves significant costs. “It’s actually much cheaper to deliver compute this way,” says Layden. “We’re about 90% less expensive on a per-megawatt basis.”
The startup is focused on inference workloads, where customers run a trained model to generate output like text or images. The U.S. currently has around 161 gigawatts of utility-scale solar, the equivalent of powering around 133 million homes. In theory, there’s enough extra capacity at those solar farms to meet all of the demand from inference customers over the next several years.
“I believe that every solar facility in the United States is a latent data center,” Layden says. Over the next year, the company plans to deploy 100 MW of computing power at solar power plants, and that can quickly scale up.
“We have so much power infrastructure already,” he says. “It’s just not being used to its full potential.”
