Anyone have any ideas why they highlight only "wide bandgap device manufacturers"? I'm hope they'd accept a winning solution with different tech, but surely there are other possibilities they could mention right at the start?
Some solutions to the problem will utilize a high frequency, high voltage switching inverter. The performance of this type of inverter is limited by the losses generated by the devices making up the inverter. The wide bandgap devices (switches in essence) offer the lowest losses for this type of topology. Furthermore, some novel inverter designs work only if they operate at very high frequencies. Only the wide bandgap devices can switch at these high frequencies.
Wide bandgap transistors have two relevant advantages: they work at higher temperatures, so you need less cooling; and they can switch higher voltages, so you don't need a bulky transformer. The only downside is, they are more expensive.
I get the impression the WBG manufacturers are partially sponsoring the prize, in hopes of getting their components adopted in the winning design.