Energy storage for data centers: how to combine resilience and ROI?
In the digital age, data centers are the backbone of our interconnected world, powering everything from cloud computing to artificial intelligence. Their uninterrupted operation is paramount, making a reliable and efficient energy supply a critical concern. Achieving optimal performance while maximizing return on investment (ROI) in energy storage systems for data centers requires a delicate balance. Advanced energy storage solutions, particularly Battery Energy Storage Systems (BESS), are revolutionizing how data centers manage their power, offering a compelling alternative to traditional methods and unlocking substantial long-term benefits.
The critical role of energy storage in data centers
Data centers operate under stringent requirements for continuous uptime and power quality. Any disruption, even for a fraction of a second, can lead to significant data loss, operational failures, and severe financial repercussions. The demand for uninterrupted service has led to the implementation of a robust power infrastructure, traditionally relying on uninterruptible power supplies (UPS) backed by diesel generators. However, as data consumption continues to surge, so does the energy footprint of these facilities. In the United States alone, data center consumption, which currently accounts for 3-5% of the electricity produced, is expected to climb to 8-12% by 2030. This exponential growth makes efficient and reliable energy storage more critical than ever.
The evolving landscape of data center operations, driven by factors such as edge computing, AI, and the increasing reliance on cloud services, further amplifies the need for sophisticated energy management solutions. Today, the main obstacle to data center expansion is grid access and power availability. BESS help address this challenge by making the data center "grid-friendly" and capable of acting as a "shock absorber" for peaks and variations in consumption, benefiting the entire electrical system.
BESS vs. diesel generators: a strategic shift
For decades, diesel generators have been the go-to backup solution for data centers. However, their reliance on fossil fuels, high operational costs, and environmental impact present significant drawbacks. Battery Energy Storage Systems (BESS) integrated in a microgrid structure able to operate either grid-connected or in island mode are emerging as a cleaner, more efficient, and ultimately more cost-effective alternative, transforming a cost center into a value-generating asset.
Feature | Diesel Generators | Microgrid with Battery Energy Storage Systems (BESS) |
| Environmental Impact | High (emits CO2, NOx, particules) | Zero direct emissions during operation |
| Operational Costs | High (fuel, frequent maintenance, overhauls) | Significantly lower (no moving parts, less maintenance) |
| Response Time | Delayed start-up (requires UPS bridging) | Instantaneous power delivery, seamless transition |
| Footprint | Large (generator, fuel tanks, exhaust systems) | Compact and high-density, saving valuable space |
| Renewable Integration | None | Seamless integration for storing and using renewable energy |
| Revenue Generation | None | Can participate in grid services and demand response programs for additional revenue |
Highlight: Shifting from diesel generators to BESS can significantly reduce a data center's carbon footprint while generating new revenue streams through grid services, turning a cost center into a value-generating asset.
Technical requirements for data center energy storage systems
Energy storage systems for data centers must meet unique and stringent technical demands to ensure maximum reliability and efficiency.
Requirement | Description |
| Uptime & Reliability | Must deliver instantaneous and uninterrupted power. Redundancy (N+1, 2N) and fault tolerance are critical to prevent any single point of failure. |
| Scalability | Systems must be modular to allow for easy expansion of power and capacity as the data center's needs grow over time. |
| Power Quality | Must deliver clean, stable power with minimal voltage and frequency fluctuations to protect sensitive IT equipment. |
| Thermal Management | Advanced cooling and ventilation systems are crucial to maintain optimal operating temperatures, ensuring battery longevity, performance, and safety. |
| Safety | Installed adjacent to high-value assets, BESS have to provide a proven safety case based on in-depth risk analyses, compliance to highest safety standards and implementation of best practises to eliminate any risk of damage to the datacenter and its environment. |
Modern BESS solutions for data centers, like Saft's Intensium® containers, are modular by design. This allows operators to scale their energy storage capacity from a few MWh up to hundreds of MWh to adapt to different entities and ensuring the infrastructure can grow with the business.
Unlocking ROI: the financial benefits of advanced energy storage
Advanced BESS offer a compelling return on investment (ROI) through operational efficiencies, reduced costs, and potential revenue generation. Beyond its function as a power back-up, BESS enable data centers to adjust their power drain from the grid, as they can substitute energy drawn from the grid, partially or totally, during given periods of time, by energy previously stored in batteries. What’s more, in an optimized system the stored energy would be of low-cost and low carbon-footprint. This opens the way for totally new business cases:
- Improved Grid Access: By enabling access to grid connections more quickly and/or at a lower cost, or by allowing for a data center expansion without necessarily reinforcing the grid connection.
- Cost Avoidance: Avoiding costs or penalties related to the consumption profile (variability, peaks).
- Energy Procurement Optimization: BESS can significantly lower electricity bills by enabling arbitrage and "peak shaving"—storing energy when grid prices are low and using it during expensive peak hours.
- Reduced Maintenance: Compared to diesel generators, BESS have far fewer moving parts and require minimal maintenance. This drastically reduces the costs and labor associated with fuel testing, filter changes, and periodic overhauls.
- New Revenue Streams: BESS can be monetized by participating in grid ancillary services, such as frequency regulation or demand response programs, creating new revenue streams.
Highlight: Data centers and other power-hungry industries using BESS can significantly reduce their energy and operational costs over the system's lifetime, leading to a total cost of ownership (TCO) that is significantly lower than traditional diesel generator setups. For example, the EnerShift project at Saft’s manufacturing plant in Bordeaux, France, resulted in an 11% saving on the cost of electricity purchase .
Saft's expertise in data center energy storage
Saft, with over a century of experience in battery technology, stands as a trusted partner for data centers seeking robust, reliable, and high-performance energy storage solutions. Their comprehensive approach encompasses not only advanced battery systems but also intelligent monitoring and extensive service support.
A notable example is Microsoft's sustainable data center project in Stackbo, Sweden, where Saft's megawatt-scale BESS have successfully replaced conventional diesel generators [3] for power back-up. There is a global trend among tech giants to secure the supply of clean power through PPA’s. BESS help to transform intermittently generated solar power into 24/7 clean power. One example is Google partnering with X-ELIO for a 128 MW PPA project in Texas that includes a 100 MW BESS [4].
Saft's Intensium® battery containers are specifically designed for demanding industrial applications, offering exceptional power and energy density within a compact footprint. Their I-Sight platform leverages artificial intelligence for remote, real-time monitoring, providing predictive maintenance capabilities that minimize the risk of unplanned downtime
Conclusion
In the rapidly evolving landscape of data centers, balancing high performance with cost-efficiency is critical. Advanced BESS solutions offer a sustainable, reliable, and economically advantageous alternative to traditional diesel generators. By embracing BESS, data centers can not only reduce their environmental footprint and operational costs but also become flexible and resilient players on the electrical grid, unlocking new revenue streams and ensuring a more profitable and sustainable future.
Frequently Asked Questions (FAQ)
BESS offer instantaneous, clean power with significantly lower operational costs and a smaller footprint. Unlike diesel generators, they produce no direct emissions and can generate revenue through grid services, providing a superior long-term ROI.
By enabling peak shaving to reduce electricity bills, drastically cutting maintenance costs compared to diesel generators, and creating new revenue streams through grid ancillary services. This combination leads to a lower total cost of ownership (TCO).
Yes. Modern BESS solutions are highly scalable and modular. They can be configured to meet the power and energy requirements of any size data center, from small edge facilities to large hyperscale campuses, and can be expanded as needs grow.
Data center help to modulate energy consumption from the grid, absorb demand peaks, and provide stability services to the grid. This can facilitate obtaining grid connections, avoid consumption-related penalties, and even generate revenue, turning a constraint into an opportunity.