Data Centers to Store Cold Air Underground in Winter for Summer Use

Metaverse Planet July 31, 2025Last Updated: July 31, 2025

0 3 minutes read

This system will store cold thermal energy underground during cold weather when electricity is abundant and cheap, significantly reducing electricity costs and lessening the burden on the grid.

In an increasingly digital world, the number of data centers is rapidly growing. With the added craze of artificial intelligence, there’s a significant increase in energy consumption. A large portion of this consumed energy is spent on cooling the heat generated by operating servers. Eliminating excess heat from the server environment can account for up to 40% of a data center’s electricity consumption.

Contents show

The Energy Challenge

Data centers already make up 9% of the US’s electricity consumption, and 40% of this 9% is related to cooling consumption, which is the subject of this news. The colossal consumption of data centers is expected to double or triple by 2030 due to the AI craze. In some regions, even decommissioned nuclear power plants are being reopened for this reason alone.

At this point, reducing the energy spent on cooling is as crucial as reducing the energy consumed by the devices themselves. Every saving made in cooling significantly brings down the total energy consumption of data centers.

Solutions for Efficiency

There are two ways to reduce this consumption. The first is to increase cooling efficiency, and the other is to operate when electricity prices are low. This allows for more efficient electricity use during periods of low efficiency, such as hot summer days or high air temperatures under the sun. Research indicates that these methods lead to significant savings.

Due to rising temperatures in summer, cooling systems become less efficient. For example, the COP value (coefficient of performance) of cooling systems in a typical data center is around 2.0 in summer, but this value can increase up to 5.0 in spring. This means 2.5 times more cooling can be achieved with the same amount of energy.

Similar differences are observed during periods like night-day and weekdays-weekends. The only solution to leverage these efficient periods is storing cold energy. However, building massive cold storage facilities is often impossible due to space constraints or proves to be very expensive.

With greater integration of renewable energy into the grid, electricity prices can drop to almost zero at certain times, even reaching negative prices. During such periods, using excess electricity to store cold underground offers a significant advantage. This brings us to an innovative solution called Cold UTES (Cold Underground Thermal Energy Storage Systems).

Cold UTES: Storing Cold Energy Underground

The goal of Underground Thermal Energy Storage Systems (Cold UTES) is to transform a large mass of soil, extending hundreds of meters deep, into a cold energy reservoir. When cooling systems operate most efficiently, this soil mass is cooled. Then, when needed, this “cold soil” acts as a kind of natural air conditioner. A new project launched by the US National Renewable Energy Laboratory (NREL) aims to standardize this system by combining it with existing technologies.

In the initial version of the system, boreholes are drilled, and a closed-loop water circulation system is installed in these wells. First, wells around 100 meters deep and 10-15 cm in diameter are drilled. This process is similar to drilling water wells, a practice familiar in our country (Turkey). Then, durable but flexible high-density polyethylene (HDPE) pipes, through which a mixture of glycol and water circulates, are lowered into these wells. This way, the massive soil mass can be cooled with very cold water when necessary, and this cold thermal energy can be extracted when needed. According to published research, another preferred method is to find and access underground water reservoirs and use them as thermal energy storage. This approach can be very effective in regions with suitable geological conditions.

The Cold UTES technology, developed to provide a sustainable response to the increasing energy needs of data centers, both saves energy and reduces the carbon footprint. Especially in this era of rising AI applications, the intelligent storage of cold energy is vital for the future of the digital world.