According to the International Energy Agency (IEA) report Energy and AI, global data center electricity consumption reached approximately 415 TWh in 2024, accounting for around 1.5% of global electricity consumption. This figure is projected to rise to approximately 945 TWh by 2030, with AI being one of the major drivers of this growth.
As electricity demand increases, so does the need for reliable and uninterrupted power. For AI data centers, an outage can do more than bring computing operations to a halt. It can also lead to:
Semiconductor manufacturing facilities, healthcare institutions, and telecommunications infrastructure face similar challenges, making reliable backup power essential for a wide range of mission-critical operations.
Modern data centers typically use a layered power architecture designed to maintain continuity when the primary power supply fails.
Layer 1: Utility Grid
Primary function: Supplies electricity during normal operation.
Layer 2: Uninterruptible Power Supply (UPS) and Battery Energy Storage System (BESS)
Primary function: Responds immediately to utility power interruptions and maintains power to critical loads.
Layer 3: Backup Power Sources, Including Diesel Generators and Hydrogen Fuel Cells
Primary function: Provides sustained power when an outage extends beyond the available UPS or battery runtime.
Coordination Layer: Energy Management System (EMS)
Primary function: Coordinates power distribution, system operation, and transitions between power sources.
In simple terms, UPS systems and batteries address the immediate interruption, generators and fuel cells provide sustained power, and the EMS coordinates the entire system to ensure that the different components work together effectively.
Power generation method: Combustion of diesel fuel.
Key advantages:
Key considerations:
Typical role: Primary long-duration backup power source.
Power delivery method: Stores electrical energy and discharges it when needed.
Key advantages:
Key considerations:
Typical role: Immediate power support and short-duration backup, often in combination with other power sources.
Power generation method: Converts the chemical energy of hydrogen into electricity through an electrochemical reaction.
Key advantages:
Key considerations:
Typical role: An alternative for longer-duration on-site power generation under suitable operating and hydrogen supply conditions.
Diesel generators remain widely used in critical facilities because of their proven reliability, broad power capacity range, ability to sustain operation, and established maintenance infrastructure.
However, fuel logistics, noise, and exhaust emissions remain important considerations. As businesses place greater emphasis on decarbonization and environmental performance, alternative backup power technologies are receiving increasing attention.
Battery systems can respond rapidly when utility power becomes unstable or unavailable. However, supporting a facility through an outage lasting several hours or longer can require substantially more storage capacity.
As capacity increases, capital expenditure, installation space, thermal management, and safety requirements become more significant considerations.
For this reason, batteries are commonly integrated with other backup power sources rather than used as the sole solution for extended outages.
Hydrogen fuel cells generate electricity through an electrochemical process rather than combustion. Their low-noise operation and low on-site pollutant emissions make them an option worth evaluating for applications such as data centers, healthcare facilities, telecommunications infrastructure, and microgrids.
However, the power generation equipment is only one part of the solution. The availability, logistics, storage, and safe handling of hydrogen are critical factors in determining whether a fuel cell system is commercially and operationally viable.
A reliable hydrogen supply strategy must therefore be considered alongside system capacity, site requirements, and the overall backup power architecture.
Not necessarily, at least not in every application.
Each technology offers distinct advantages. Diesel generators provide proven long-duration backup, batteries deliver rapid response, and hydrogen fuel cells offer an alternative for low-noise power generation with low on-site pollutant emissions.
The more practical approach is often to integrate multiple technologies into a coordinated system, allowing each to perform the function for which it is best suited.
The optimal configuration depends on the facility's power requirements, expected outage duration, site conditions, fuel availability, operating costs, and sustainability objectives.
1. How long must the facility remain operational during a power outage?
Does the facility need to maintain power for a few minutes, several hours, or an extended period of independent operation?
2. How much critical load must be supported?
The size and characteristics of the critical load directly affect equipment capacity, system configuration, and total investment.
3. What are the site constraints?
Available space, ventilation, noise restrictions, surrounding infrastructure, and local regulatory requirements can all influence technology selection.
4. How will fuel or hydrogen be supplied and stored?
Fuel availability, supply reliability, storage capacity, and safety management must be incorporated into the overall design.
5. How will the different systems be integrated?
Without effective coordination through an EMS and a properly designed control architecture, individual components may not deliver their full potential as part of the overall backup power system.
Data center backup power refers to the systems that maintain electricity supply to servers and other critical equipment when utility power is interrupted. These systems typically include UPS units, battery energy storage, diesel generators or other backup power sources, and an EMS to coordinate system operation.
A UPS provides immediate power when the utility supply is interrupted, helping prevent disruptions to critical loads. A generator provides sustained power for longer outages. The two are typically used together to maintain continuity of power.
Battery energy storage offers significant advantages in rapid response and short-duration backup. However, supporting loads through extended outages may require substantial storage capacity, increasing costs, space requirements, and thermal management demands. In many applications, batteries are therefore combined with other backup power sources.
They can be, depending on the application. Key factors include hydrogen availability, storage and delivery arrangements, system capacity, safety requirements, and overall cost. Hydrogen fuel cells are an option for facilities where these conditions can be adequately addressed, but their suitability must be evaluated on a site-specific basis.
When operating on pure hydrogen, fuel cells generate electricity through an electrochemical reaction, with water and heat as the primary by-products. They can therefore offer low on-site pollutant emissions and low-noise operation. The overall environmental impact also depends on how the hydrogen is produced, transported, and stored.
The rapid growth of AI and high-performance computing is increasing data center electricity demand and reinforcing the need for reliable power infrastructure. An interruption can affect digital services, data processing, and business continuity, making a well-designed backup power system an essential part of data center resilience.
Competition in the AI era is not determined by computing power alone. It also depends on whether the underlying energy infrastructure can deliver reliable, resilient, and sustainable electricity.
For data centers, backup power should be considered an integral part of the overall energy architecture rather than an isolated piece of equipment. By evaluating load requirements, outage duration, available energy sources, and system integration from the outset, operators can develop a backup power strategy that better supports operational continuity and long-term business needs.
Want to find the right backup power solution for your site? 《Contact Us》
Source: IEA《Energy and AI》
