Is energy storage the secret weapon for low carbon data centres?

Weather-dependent wind and solar energy sources pose challenges in predicting energy generation, adding complexity for operators.

Data Centres require a consistent power supply, which renewables alone cannot provide. However, when coupled with Battery Energy Storage Systems (BESS), excess renewable power can be stored for use when energy generation drops while demand remains steady. This approach maximizes local energy generation without relying heavily on the grid.

Individual hyperscale data centres consume vast amounts of energy, equivalent to powering over 200,000 homes. The proliferation of smartphones and connected devices contributes to server use, consuming 4% of global electricity and nearly 2% of global carbon emissions. This presents an opportunity for change and innovation.

The data centre industry is responding with various strategies, such as buying renewable energy, carbon offsets, or emissions credits, setting emissions reduction targets, and working with suppliers to reduce environmental impacts. Achieving a carbon-free or carbon-negative future will require a renewed focus on energy storage.

Traditionally, diesel generators have served as backup power sources, rarely emitting significant carbon due to infrequent use during grid outages. However, as decarbonization efforts grow, discussions about transitioning to cleaner backup energy sources are gaining momentum.

Renewable sources lack the infrastructure to fully replace conventional power, but onsite generation can help fill energy capacity gaps and support grid stability. Data centres must balance sustainability goals with the need to provide reliable power to essential services like banks and hospitals.

The transition to carbon-neutral or carbon-free data centres will likely center on energy storage technology. Batteries, particularly Lithium-Ion chemistries, are already integral to data center power operations. Large-scale users are expanding their use of batteries, making them more prominent in backup systems and grid-attached storage.

However, the cost of batteries remains a challenge, as it scales linearly with capacity. Battery prices may decrease over time, making them more economically viable. Yet, batteries have limitations, primarily serving as a bridge between grid outages and diesel generator activation. They are not currently capable of powering an entire data centre during prolonged grid outages, a crucial consideration for uptime-focused businesses, especially in disaster-prone regions.

In summary, data centers are working to incorporate renewable energy and energy storage solutions to reduce their environmental impact while ensuring uninterrupted operations. Batteries play a crucial role but face cost and capacity limitations that may evolve with time.