How standby power is evolving in step with carbon reductions
How standby power is evolving in step with carbon reductions
Standby power generation plays a critical role across many different applications, in the instance of a mains outage or unpredictable supply – such as keeping vital hospital equipment functioning, maintaining operations at utility plants and ensuring datacentres stay online.
At present, the most common fuels used in backup generators are gas and diesel. So, although much discussion on the energy transition is focussed on how we move away from the use of fossil fuels for mains power, if we are to truly achieve net zero carbon then the industry needs to ensure that standby power can also be produced through low and, ultimately, carbon-free means.
Ensuring reliability
The current reliance on diesel generators for standby power is well established, primarily because of their practical benefits. They are readily available, reliable as a mature technology and able to quickly ramp up to seamlessly cover issues with mains power supplies.
Given that high-profile standby power users such as hospitals and datacentres must mitigate any risks that may be posed to maintaining mission critical services, the advantages in terms of reliability that existing technology offers must be carefully considered as we transition away from fossil fuels.
Indeed, in these understandably risk-averse sectors, we will likely see a phased transition to a balance between maintaining the benefits of existing technology and the importance of using carbon-free energy.
HVO proving a smart first step
A first step in this transition is the growing use of Hydrotreated Vegetable Oil (HVO). Produced from certified waste fats and oils, HVO is manufactured using a synthesised process with hydrogen to offer a more sustainable alternative to fossil fuels. Although not entirely carbon-free, HVO can eliminate up to 90% of the carbon emissions compared with the production and use of conventional diesel.
Another key advantage is that it can be used as a drop-in replacement for diesel in many engines, as well as used with existing diesel or biodiesel stocks. For example, provided the fuel meets standard requirements, Cat® generators built after the year 2000 are able to run on HVO.
Given the ease with which they can be integrated into existing assets, we have seen growing interest in the use of HVO in tandem with diesel to lower the carbon footprint of standby generators.
Whilst use of HVO with conventional diesel has been the most common approach, there have been high profile cases where a move to 100% HVO has been taken – allowing even greater reductions in carbon emission. Last year Microsoft announced that all Cat generator sets at its new datacentres being constructed in Sweden would run on HVO, providing the final element to obtaining all of its energy needs from renewable sources.
“We have worked extensively to ensure that our new data centers in Sweden will be among our most sustainably designed and operated in the world,” observes Noelle Walsh, corporate vice president, Cloud Operations and Innovation at Microsoft. “Caterpillar and the Cat dealer network have developed innovative power solutions that support Microsoft and our unwavering commitment to carbon reductions. Cat generator sets at Microsoft data centers help us keep availability promises to our customers even when grid power fails, providing continuous energy and uninterrupted cloud services.”
In short, with largely immaterial differences in performance and consumption in comparison with diesel, HVO provides an excellent next step to reducing carbon emissions. Crucially, it offers flexibility with any HVO to diesel ratio between 0% and 100% possible depending on the specific demands and preferences of each project.
Longer term benefits of hydrogen
Whilst HVO is a convenient and highly effective drop-in replacement for existing diesel equipment, it is not entirely carbon-free. Furthermore, the sheer scale of demand for fuel means that it is unlikely to become a permanent solution due to its production being limited by how much vegetable oil and fat is available globally.
Hydrogen has been touted as a more likely long term solution, with advances in blue (the splitting of natural gas into hydrogen and CO2, with the resulting carbon captured) and green (splitting water by electrolysis into hydrogen and oxygen) production set to help create the volumes needed to replace fossil fuels on a global scale.
Whilst those production volumes are yet to come, plans are in action and it is an area that should be explored when looking at the next generation of sustainable equipment. As with HVO, a blended approach may be the likeliest next step with gas gensets configured to allow for a blended fuel containing up to 25% hydrogen.
Manufacturers such as Caterpillar are rolling out gas generators configured out-of-the-factory to enable operation on natural gas blended with hydrogen. Adaptation of existing gensets can be done with the use of retrofit kits for some equipment, making it an appealing quick win as hydrogen availability increases.
