Proton-exchange membrane (PEM) fuel cells are more efficient than other alternative generator technologies as a way to provide backup power to datacenters in certain climates, according to a recent study.

"Hydrogen fuel cells have emerged as a potentially dependable solution to address the intermittent nature of weather-dependent renewable energy sources such as wind and solar," according to a canned statement from datacenter specialist Equinix, which teamed up with the National University of Singapore (NUS) to explore the matter last year.

"When renewable energy generation fluctuates due to dynamic weather conditions, hydrogen fuel systems could act as an efficient backup power source so that datacenters stay online," it added.

The study assessed the power methods based on reliability, cost, operating conditions and environmental impact.

All scenarios considered included an auxillary battery system that was designed to ensure uninterrupted power supply to the critical load, even when considering start-up time and ramp rate to maximum power.

But PEM fuel cells, which rely on a chemical reaction between hydrogen and oxygen to generate electricity, scored the highest efficiency at a range of 45 to 57 percent. They were followed by alternative generator technologies (44-47 percent), and hydrogen-fueled generators (34-40 percent).

Fuel efficiency followed the same pattern: PEM fuel cells used the least fuel, then alternative generator technologies and hydrogen-fueled generators.

However, when it came to operating conditions, PEM fuel cells and hydrogen generators had tighter parameters and required tight control of temperature, humidity and ventiliation. PEM fuel cells required operation between 0°C and 50°C and hydrogen generators between 15°C and 40°C.

Comparatively, alternative generators were given the range of -20°C to 50°C - a range double that of hydrogen generators.

The authors concluded that PEM fuel cells are the obvious choice for backup power in potentially cloudy or windy environments where temperatures rarely venture below 0°.

"Our analysis highlights proton-exchange membrane (PEM) fuel cells and alternate generator technologies as promising backup power solutions, especially in tropical climates," explained NUS Professor Lee Poh Seng.

PEM fuel cells had one other feature going for them which the generator options did not: a lack of greenhouse gas emissions.

Next Equinix and NUS plan to look at costs associated with providing continual power to datacenters.

As AI use continues to grow, the race to find alternative ways to power datacenters accelerates. According to AMD CEO Lisa Su in February, CPUs and GPUs have doubled in performance every 2.4 years, but power efficiency frankly hasn't.

AI clusters used to train large language models can require power on the order of supercomputers.

This has led some datacenter operators - including Microsoft and Amazon - to create micro power grids.

And last month, Microsoft posted a job ad looking for a nuclear power program manager to oversee its datacenters with nuclear reactors. ®

https://www.theregister.com//2023/10/04/fuel_cell_datacenter_power/