Wednesday, 12 August 2026

Underground thermal energy storage can hold servers in computing facilities at operating temperature through every season, according to a new national laboratory study reported by CleanTechnica.

The cooling load at stake is large. CleanTechnica reports that keeping computing equipment cool can consume as much as 40% of a facility's total annual energy consumption, alongside water use.

The study frames the subsurface as a year-round heat sink, rather than a seasonal supplement to conventional chillers.

Data centers of 10 MW or more in Ireland must cover at least 80% of their energy demand with new onsite renewable generation and storage under the country's Large Energy User Action Plan (LEAP), according to pv magazine.

The threshold sets the design constraint for any large computing site seeking to connect: the renewable capacity and the batteries have to be new and located on the site itself, rather than contracted from existing assets elsewhere on the system.

The rule lands on a demand base that is already unusual by international standards. Data centers took 23% of national electricity consumption in Ireland in 2025, pv magazine reported.

The state is spending heavily on the wires alongside the onsite mandate. In December 2025, the Irish government announced an EUR 18.9 billion (USD 22.2 billion) investment package for electricity grid infrastructure out to 2030, according to pv magazine.

Supply of the technology the mandate depends on is scaling from a modest base. Solar Ireland's 2026 market outlook report estimates that total connected solar capacity in Ireland will surpass 3.3 GW by year's end, pv magazine reported. That figure covers the entire national fleet, not just the behind-the-meter systems LEAP would require large energy users to build.

The gap between the 80% onsite requirement and the size of the installed solar base is the operative tension. A single hyperscale campus drawing tens of megawatts continuously would need substantial dedicated generation and storage to reach the threshold, while the whole country's connected solar capacity is measured in low single-digit gigawatts.

Sandia and Elemental Nuclear will jointly design, build and demonstrate supercritical CO2 power generation at two scales, starting with a 1 MWe natural-gas- and waste-heat-fired power and cooling system aimed at small modular data centers and remote military installations, according to Power Engineering.

That first unit is expected to be operable in 2027, with supporting commercial system deliveries beginning in 2028, Power Engineering reported.

Elemental then plans a scaled-up 10 MWe machine engineered to run on a range of heat sources, including the company's ISTR nuclear reactor.

The technical case rests on temperature. In the Brayton Cycle, supercritical CO2 can reach 1,290 degrees Fahrenheit (700 Celsius), hotter than steam, and the CO2 stays inside the system rather than being released as a greenhouse gas, according to Power Engineering.

The pairing of a gas- and waste-heat-fired demonstration with a later nuclear-capable unit gives the same power block two distinct customer routes: near-term deployment at small data center and remote base sites, and a reactor-coupled configuration once the larger 10 MWe design is engineered.