California-based startup Rune Energy has found an unconventional way to put excess solar energy to work: rather than curtailing generation that the grid cannot absorb, the company deploys modular data centers directly beside solar farms and connects them straight to the DC bus. According to spectrum.ieee.org, the solution — called RELIC (Renewable Energy Linked Intelligent Compute) — can be up and running within a week and powers compute nodes built around Nvidia GPUs.
Key facts:
- Rune Energy estimates that roughly 50,000 GWh of solar generation is wasted globally each year due to grid constraints.
- A single RELIC module draws up to 100 kW and can house between 128 and more than 2,000 Nvidia B300 accelerators.
- Connecting to a solar farm’s DC bus and bringing the data center online takes one week.
- The company’s target is 100 MW of compute capacity within 12 months.
A DC Bus Instead of a Grid Connection
Solar panels produce direct current (DC), which an inverter converts to alternating current (AC) for delivery to the grid. When generation exceeds inverter capacity, a portion of energy is lost to inverter clipping; curtailment losses and unplanned equipment shutdowns add further waste on top of that. Rune Energy taps the DC bus upstream of the inverter, stepping voltage down through DC/DC converters to levels suitable for GPU operation. The company signs direct power purchase agreements (PPAs) with solar farm owners, buying the energy that would otherwise go unrealized.
Co-founder and CTO Varun Palivela describes today’s energy landscape as “abundant but stuck in time and space”: the resource exists, yet it cannot be routed to where it is needed. For large data centers, he argues, access to electricity is “not a real bottleneck — it’s a resource-allocation question.”
A Furniture-Sized Container Holding Thousands of Accelerators
Each RELIC unit is a self-contained enclosure approximately 2.4 m long, 0.6 m wide, and 1.5 m tall, integrating networking equipment, a cooling system, power electronics, and GPUs. It weighs around 900 kg and draws up to 100 kW. A single unit accommodates between 128 and more than 2,000 Nvidia B300 accelerators; multiple modules can be linked into a larger cluster. To enable around-the-clock operation on overcast days and overnight, each RELIC includes an integrated battery system.
Rune positions itself as a product company, not a construction firm: the modules are manufactured at its own facility in Mountain View, California, and delivered ready to deploy. “Connect two wires to the DC line and you’re done,” is how co-founder and CEO William Layden describes installation. He notes that the company recently brought a data center online within a week of receiving an order. This approach sidesteps the shortage of transformers, switchgear, and cooling infrastructure that stretches conventional data center construction into months or years.
Does DC Really Deliver an Advantage?
The primary benefit, in Crozier’s view, is lower component costs. Crozier also highlights a critical question: correctly sizing battery capacity. Because RELIC has no backup grid connection, the batteries must cover nights and cloudy days, while the solar array must be able to recharge them during favorable conditions.
A New Business Model for Solar Farm Operators
Rune’s approach is an example of the broader behind-the-meter trend: data centers are increasingly connecting directly to generation sources, bypassing the queue for new grid interconnection. For solar power plant owners, this represents a potentially new revenue stream — selling energy that previously went to waste. For the solar technology sector as a whole, it is another argument for co-locating generation, storage, and useful load on a single site.
Whether the model scales beyond the United States will depend on GPU costs, PPA terms, and local regulatory frameworks. But the underlying principle — consuming on-site the energy that the grid cannot accept — is sound for markets where output restrictions on solar farms have become a systemic problem. Solar power plant operators should watch developments like this closely: if the approach proves scalable, it could turn “lost” megawatt-hours into a standalone revenue source.
Sources: spectrum.ieee.org
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Prepared by the Alternative Energy editorial team with the help of AI based on the sources listed; facts and figures were checked against them during automated editorial review. How we prepare articles