It is no secret that data centres are currently facing significant challenges in terms of power reliability, sustainability and cost management. Grid instability, congestion and curtailment are on the rise, along with volatile energy costs and demand charges. Moreover, as the rise of Artificial Intelligence (AI) and other high-density loads place increased stress on existing power architectures, concerns around diesel emissions and run-time limits are growing.
For today’s data centres, it is becoming increasingly important, yet difficult, to achieve 99.9% uptime, power reliability and redundancy while minimising the impact on grid stability, avoiding outages and delivering scalable and sustainable solutions compatible with high-density loads.
The importance of co-locating BESS with generators
At a fundamental level, a data centre’s architecture can be described as a combination of grid utility, transformer, Uninterruptible Power Supply (UPS) – that is, battery storage -, generators and IT loads (or servers).
Battery Energy Storage Systems (BESS) stand out for their ability to augment, or even replace, traditional UPS solutions, providing fast response and improved ride-through capability. When co-located with generators, BESS can offer immediate bridging power during grid loss and help smooth generator load. Moreover, advanced BESS solutions with grid-forming capabilities can support black-start processes and enable fail-safe islanding.
By leveraging the co-habitation of BESS with generators, it is possible to ensure the stability, flexibility and fast response required to meet the needs of modern data centres. In certain regions, BESS can also generate revenue by participating in grid services. Due to their performance and lifecycle advantages, lithium-ion (or li-ion) batteries are currently the most common choice.
In other words, the co-habitation of BESS with generators delivers a wide range of operational, financial and environmental advantages. It helps to improve power quality, enhance reliability and reduce generator wear. From a financial standpoint, it is instrumental in lowering energy bills, cutting fuel costs and generating income through grid services. Finally, co-locating BESS with generators brings remarkable environmental benefits, playing a pivotal role in lowering carbon emissions and accelerating the adoption of renewable energy.
These advantages should, of course, be assessed as part of a broader strategy that also considers the investment required and operational costs.
BESS and renewable support for data centres
There is also the possibility to co-locate BESS with renewable generation, when the main power supply comes from renewable energy sources, whether or not they are paired with generators. This approach is mainly adopted in the US, where lead times for grid reinforcement or gas turbine delivery tend to be too long. In such cases, the data centre is off grid, with renewable generation as the main power supply and, of course, BESS.
Selecting the right equipment to ensure compatibility
In a rapidly evolving technical environmental, it is crucial to select systems and equipment that facilitate ease of upgrade and compatibility with control management systems. Supply chains with in-house manufacturing capabilities can minimise compatibility risks for core components such as Battery Management System (BMS), Power Conversion System (PCS), Supervisory Control and Data Acquisition (SCADA) and Energy Management Systems (EMS).
BESS providers capable of manufacturing these components internally can ensure that upgrades only involve diagnostic changes rather than costly and time-consuming equipment replacement.
PCS and SCADA systems should be designed to accommodate upgrades and allow for smooth transitions, although with diagnostic adjustments. For mechanical components, including generators, the ability to provide additional sets for upsizing or availability of spare parts should also be considered. In essence, the co-location of BESS with generators is comparable to the solutions used for transient loads in other sectors, such as ferries.
Derisking data centre power management
Outsourcing power load to a single, experienced, provider with full lifecycle capabilities, including Operations and Maintenance (O&M) for both BESS and generators, enables data centres to focus on IT load requirements.
Bankable BESS providers can also offer long-term warranties and guaranteed availability as part of O&M agreements. In some cases, these packages may include O&M for generators, further mitigating operational risks.
The pillars for modern data centres
Co-locating BESS with generators at data centres is paramount to delivering instant backup power, cost optimisation and demand charge management, improved renewable integration and sustainability as well as grid support services. This approach is all the more valuable as it enables data centres to respond effectively to the challenges posed by highly volatile energy markets dynamics at a global level.
By carefully selecting systems and equipment that unlock ease of augmentation, compatibility, and robust O&M supported by warranties, data centres can add an additional layer of risk mitigation and significantly enhance their resilience.
Article by Bali Sahdra, UK & Ireland BESS Manager at Nidec Conversion
Article by Bali Sahdra, UK & Ireland BESS Manager at Nidec Conversion
More energy management stories can be found here
