HOT it would be nice in my opinion if geothermal generator could produce little energy just by being in contact with lava (like the water mill does) obviously less than the 20 EU/t using the bucket/cells... making the proportion with the water mill and considering the difficulty in working with lava I'll say a 0.2 EU/t per block of adjacent lava maybe even 0.25...
COLD I'm not sure if it's still true cause I haven't tried for a while to put solar panels in a snow biome... if it still true that the snow layer prevent the solar panel to collect sun power would be nice to change it (if it's not ignore this second part)... for someone who likes snow biomas (like me) it's quite impossible to put a solar panel farm
solution options:
1) prevent the snow to deposit on the panels (make them emit a little light?)
2) make the panel collect the sun light through the snow layer
3)dunno use your imagination 
