Here is a study of an inverter, looking at power transistor options:
I saw https://www.infineon.com/dgdl/irg4psh71udpbf.pdf?fileId=5546d462533600a401535648c1bb233d first, which is 1000V 50A - safe for a 20kW system, looks like we need 4 of them? IGBT obsolete, need 4 of them at $13 each. 
Here is the thesis - https://www.diva-portal.org/smash/get/diva2:17851/FULLTEXT01.pdf. P. 55 shows weight and power.
Is the bottom line 20kW for $50, or $2.5/kw of switching power?