Microgrids for Data Centres – from stabilisation to inertia to clean generation
Osterode, Germany - 10th January 2022
The evolution of microgrids and data centre operations present an opportunity to build sustainable off grid power systems that encompass clean power generation, stabilisation and protection.
But just as there is no single data centre design there will be no one microgrid type for every data centre environment.
Microgrid development for data centre applications is about selecting the best and most adaptable components tailored to the demands and needs of particular facilities.
Data centres sitting on microgrids are increasingly being evaluated in response to stability issues within the transmission network. These are expected to rise as more invertor-based generation becomes the primary power source.
Piller (as part of the Langley Holdings Power Solutions Division) products for data centre microgrids integrate in ways that provide significant advantages over traditional static UPS and battery storage backed invertor-based approaches.
They deliver different functionality to the microgrid network in terms of frequency, inertia and improved performance.
Solutions integrate at medium voltage matching grid operator and transmission networks which typically perform at MV.
Piller’s grid gate system provides a point of isolation between grid power transmission and the microgrid where it helps to isolate the microgrid from grid issues that can be detrimental to the performance of the data centre facility. The integration of Piller stabilizers at the local microgrid level delivers voltage and frequency stabilisation without complex control systems.
Using rotary UPS technology helps stabilize the microgrid network. Given the intermittent nature of RERs, when generation dips or disappears there is a risk that the microgrid will not function properly.
Wherever generation from solar and wind are prevalent using the natural properties of the rotating machine provides a stable reference source to manage such intermittent power sources.
In order to maximise the use of renewable generation an alternative source of stabilisation and clean back up power is required.
That is what the rotating stabilizers can deliver for data centers directly or virtually connected to RERs.
Grid stabilizers can integrate with flywheel energy storage solutions to offer a very fast dynamic network stabilisation. They can also integrate with batteries energy storage systems to offer longer term back up.
Genset Back up and Primary Power
Data centre power chains exist to maintain the power to the IT load and the delivery of constant power to from the grid is the key to operation. In the event of loss of the grid power chains rely on gensets for many hours of back up.
However, as operators look to microgrids for off grid primary power, additional gensets on the microgrid will at times be the primary source. Liquid fuelled hydrogen ready medium speed engines are needed for microgrids to maintain and deliver a reliable service at the required capacity.
For microgrid applications Bergen Engines solutions scale from 1,500kWe single units. Bergen’s largest single unit provides 11,830 kWe of power. Through simple paralleling Bergen engines scale to tens and even 100s of MWs.
Bergen Engines Medium speed liquid fuel engines have a clear sustainability roadmap from diesel to liquid natural gas (LNG) to LNG/hydrogen blend and ultimately to pure Hydrogen operation delivering zero carbon, clean, efficient power.
Data centre microgrid needs
Data centres are facing two major issues. On one level operators are being told not to put too much strain on the grid and to become part of the solution to potential capacity shortfalls. At the same time all data centres and microgrids require protection, power conditioning and stabilisation to protect the load.
Both mean exploring ways to offer sustainable solutions that do not over rely on fossil fuels in order to generate their own power.
There are several key scenarios, in integrated microgrid mode they must keep operating when they lose the main grid unexpectedly, they must be able to run in island mode when they come off the grid at times of capacity constraint (planned) and when co-generated power can be made available to feed back to the main grid through an integrated microgrid.
The initial considerations for running on local integrated or islanded microgrids to achieve those primary objectives include access to base load generation as the system transitions between different power sources (at night for solar or at periods of no wind). An engine capable of moving from diesel to natural gas with a portion of some hydrogen achieves this.
Natural gas engines (which will deliver big reductions in carbon output as hydrogen mixes are increased) combined with rotary based technologies for ride through, protection and stabilisation are key components of the step-by-step journey to sustainable microgrids for data centres.
As solutions evolve there will be no one approach that will deliver everything in every use case. But the key is making the correct evaluation that will provide an adaptable and flexible microgrid solution that will meet both the long-term sustainability and changing operational needs of the data centre.