1. Generator must be renamed to "Solid Generator" or "Solid Fuel Generator" (SFG). It's much more logical, when we have Solid Heat Generator and Fluid Heat Generator.
2. Why "Semifluid Generator"? maybe simply "Fluid Fuel Generator" (FFG)?
Tiny research:
1. SFG can produce only 10 EU/t, but FFG can up to 16, (and with BC Gas even 32 EU/t)!
2. SHG produces only 10 HU/t (what?!) and SHG+Stirling pair gives only 5 EU/t! 
Conclusion: Best beginner's generator is FFG, but chain FHG-SteamEngine-KineticGenerator may be much productive.
Geothermal generator is an obsolete device and can be fully replaced by Liquid Heat Exchangers, that can generate up to 50 Eu/t whti Stirling and even more with Steam! 