In the decarbonized world of the future, electricity will become the dominant energy with 60%-70% share in 2050. Biofuels will rise, dependence on fossil fuel-based energy will significantly decrease and hydrogen will increase.
It’s well documented that tech companies are making carbon neutral commitments (many are already there) and leading the race to net-zero emissions. Data centers have a good chance to be one of the earliest adopters of green hydrogen as the fuel source for PEM fuel cells replacing diesel generators.
Data centers are depended on for the automation and operation of many industries. When data centers are down, electricity may black out, transportation may come to a halt and communications can go dark, so data centers need to be powered with redundant utility sources and short-term backup from redundant uninterruptible power supplies and backup generators for longer-term backup (many days with on-site storage and longer with refueling).
Recent global droughts as well as geopolitical and supply chain/tariff issues have led to reduced hydropower and slower-than-expected wind and solar deployments, resulting in power instability in many areas of the world. The quick answer for data center operators is to increase the long-term backup capacity and redundancy of diesel generators. But that goes against the sustainability commitments of many companies.
Instead, it is important to implement solutions to get from point A (diesel) to point B (carbon-free backup).
Step 1: Biodiesel And Green Renewable Diesel
Traditional, petroleum diesels have been around for a long time. Although noisy and inefficient, they are reliable. The first step I recommend when taking this journey to higher sustainability is to start mixing your petroleum diesel with biodiesel or, even better, a green renewable diesel “drop-in.”
There are actually two different things—biodiesel and green diesel with different properties and carbon footprints. Environmental Protection Agency (EPA) research indicates that biodiesel, which has the chemical name fatty acid methyl ester (FAME), emits 11% less carbon monoxide than traditional diesel, but biodiesel can only be mixed with traditional diesel at a 5%-20% ratio, which limits its impact.
Green renewable diesel (also known as RD) is produced from oilseed crops, distillers corn oil, used cooking oil and tallow. These are second-generation biodiesels and are a direct substitute for traditional petroleum diesel at 100%.
According to Argonne National Laboratory, RD from soybean, canola and carinata oils range from 40% to 69% GHG reductions. Even better, converting tallow, used cooking oil and distillers corn oil to RD could achieve up to 86% lower GHG than petroleum diesel, but these feedstocks have a very limited supply.
Step 2: Battery Energy Storage
A two-hour lithium-ion battery can transform a data center into a distributed energy resource (DER) living on the grid. Along with being capable of reacting to supplying backup power to the data center during extended outages, they can also be used to alleviate grid stresses that can cause outages.
For example, if the grid is subject to very high power demand on the entire grid, as is common during a heat wave, data centers can use their microgrid systems to reduce load on the grid, improving overall grid flexibility. When this battery system is charged with renewable energy (wind, solar, hydro), it emits zero carbon during operation. And when there is a surplus in renewable supply, instead of curtailing renewable production, this surplus energy is used to charge the battery storage.
Step 3: Fuel Cells Powered With Green Hydrogen
Diesel generators will likely be replaced with fuel cells that have cleaner fuel options such as blue or green hydrogen. Blue hydrogen involves fossil fuels and carbon capture and is roughly 10%-12% lower GHG emitting than standard gray hydrogen. Green hydrogen will be produced from water in an energy-intensive application by electrolysis.
Compressing, liquifying, transporting and storing the green hydrogen is also very energy intensive. Therefore, the process must use renewable energy supply everywhere in the entire supply chain for green hydrogen to emit zero carbon during operations. For that reason, significant renewable electrical generation capacity will need to come on-line before green hydrogen can become abundant and viable.
Historically, long-term backup power diesel-powered systems for data centers were only used during very rare catastrophic events. Void of catastrophic events, the emissions were limited to monthly or quarterly diesel generator testing. However, today’s grid instability is shining a light on the need to make these long-term backup systems emit less harmful carbon emissions as they are going to be in operation much more frequently.
There is a road that data center operators can take by sourcing renewable diesel, adding battery storage and replacing diesel generators with fuel cells powered with green hydrogen when green hydrogen becomes available at scale. These backup systems can also be increasingly grid-interactive and data centers can be used as a key component for grid stability to the benefit of local residents and communities.
This article was previously published in Forbes.