Well, here are three more observations. You can get it to run with under 2kg/ steam, and sometimes it will even run at full power in this situation (though not always at full power).    You can trick it to run by having one spot hot.  For example you can only heat one tile of a few mg steam, and the rest of the steam can be below 125C.  It will still run.    Any port under the turbine that does not have steam will result in 400g/s less steam. However, you can process higher temp steam and still get full power output.  A single tile of petro at above 125C will keep the turbine running at all times, regardless of steam temp, so you can definitely use this to catpure all steam from a steam geyser and turn the steam into 94.5C.    Current testing gives quite sporadic results.  We'll tame this beast soon. It appears that the power output is directly related to the thermal energy input (up until you hit max power, then you just lose energy).  This is a great change in the right direction. It seems to be.  The max temp is 195C if all 3 ports are open.  That temp goes up if you have fewer ports open.It's around 260 with 3 ports open and around 340 with 2 ports open.  With only 1 port open, it looks like the game prevents you from going above half power, so a 1 port open turbine is considered bad by the code.  However, 2 ports open can still get you full power with 340C steam.   Here's some formulas that show what's going on. Input temp 195C - output temp 95C - 5 ports open
(195C-95C)*2000g*4.179 = 835.8kDTU/s Input temp 261.6666C - output temp 95C - 3 ports open
(261.666C-95C)*1200g*4.179 = 835.8kDTU/s Input temp 345C - output temp 95C - 2 ports open
(345C-95C)*800g*4.179 = 835.8kDTU/s The numbers above suggest that the amount of power created we can compute perfectly. This gives us a way to directly compute power from thermal energy in a body, provided we don't exceed the max.  So, a new exploit is to (1) matter convert gas to chlorine, (2) bump up the temp to high levels using whatever means you want using low SCH properties of chlorine, (3) matter convert the chlorine to steam, and finally (4) send the steam to the turbine. Essentially, any element conversion process (matter conversion or even state changes of some things) that changes the SCH of something can now be exploited by the turbine for power.