I looked at this white paper and I’m not sure that I’m sold on their supercapacitor’s ability to smooth out the volatility for large load swings that these AI data centers are supposedly experiencing. I am also not an electrical engineer so I could be dead wrong but here is what I am curious about:
On page 8, it shows a graph of how the supercapacitor is able to accommodate the volatility. The example used is a 300 kilowatt load with swings between 40% and 100%, cycling between the min and max about once per minute. In this example, it appears that the supercapacitors are able to do the job for this load profile. However, from what I’ve heard, these large AI data center loads are orders of magnitude larger than that and can swing between 40-50% around 10 times per minute and even multiple times per second. For example, a site with a peak load of 160 megawatts swinging 60-80 megawatts 10 times per minute. 160mw is over 500 times larger than 300kw. Can the supercapacitors handle that? Let’s assume that all of the supercapacitors together could handle an 80mw swing at a 160mw site once per minute. Could it handle 10 times per minute? If a supercapacitor has a lifespan of 1,000,000 cycles, at 3,000 cycles per day (~2 cycles per minute) the lifespan is less than 1 year.
I assume that the 300kw load in their example is meant to reflect extreme conditions on a single GPU rack, and obviously there are multiple supercapacitors at work here inside the data center. I don’t know how all of this works in terms of coordination between the racks but I still am interested in seeing how Bloom Energy’s solution will solve for these wild fluctuations.
https://www.bloomenergy.com/wp-content/uploads/load-following-solid-oxide-fuel-cell.pdf