neoclouds on top of silicon need a lot of power that they can’t get because they can’t get substation big enough, or maybe provider denied it, so they decided that homemade is just as fine. in order to turn some kind of fuel (could be methane, or maybe not, who knows) into electricity they need gas turbines and a couple of weeks back there was a story that crusoe got their first aeroderivative gas turbines from GE https://www.tomshardware.com/tech-industry/data-centers-turn-to-ex-airliner-engines-as-ai-power-crunch-bites this means that these are old, refurbished, modified jet engines put in a chassis with generator and with turbofan removed. in total they booked 29 turbines from GE, LM2500 series, and some other, PE6000 from other company called proenergy* and probably others (?) for alleged 4.5GW total. for neoclouds generators of this type have major advantage that 1. they exist and backlog isn’t horrific, the first ones delivered were contracted in december 2024, so about 10 months, and onsite construction is limited (sometimes less than month) 2. these things are compact and reasonably powerful, can be loaded on trailer in parts and just delivered wherever 3. at the same time these are small enough that piecewise installation is reasonable (34.4MW per, so just from GE 1GW total spread across 29)

and that’s about it from advantages. these choices are fucking weird really. the state of the art in turning gas to electricity is to first, take as big gas turbine as practical, which might be 100MW, 350MW, there are even bigger ones. this is because efficiency of gas turbines increases with size, because big part of losses comes from gas slipping through the gap between blades and stator/rotor. the bigger turbine, the bigger cross-sectional area occupied by blades (\~r^2), and so gap (\~r) is less important. this effect is responsible for differences in efficiency of couple of percent just for gas turbine, for example for GE, aeroderivative 35MW-ish turbine (LM2500) we’re looking at 39.8% efficiency, while another GE aeroderivative turbine (LMS100) at 115MW has 43.9% efficiency. our neocloud disruptors stop there, with their just under 40% efficient turbines (and probably lower*) while exhaust is well over 500C and can be used to boil water, which is what any serious powerplant does in combined cycle. this additional steam turbine gives about third of total generated energy, bringing total efficiency to some 60-63%.

so right off the bat, crusoe throws away about third of usable energy, or alternatively for the same amount of power they burn 50-70% more gas, if they even use gas and not for example diesel. they specifically didn’t order turbines with this extra heat recovery mechanism, because, based on datasheet https://www.gevernova.com/content/dam/gepower-new/global/en_US/downloads/gas-new-site/products/gas-turbines/gev-aero-fact-sheets/GEA35746-GEV-LM2500XPRESS-Product-Factsheet.pdf they would get over 1.37GW, while GE press announcement talked about “just under 1GW” which matches only with the oldest type of turbine there (guess: cheapest), or maybe some mix with even older ones than what is shown. this is not what serious power generating business would do, because for them every fraction of percent matters. while it might be possible to get heat recovery steam boiler and steam turbine units there later, this means extra installation time (capex per MW turns out to be similar) and more backlog, and requires more planning and real estate and foresight, and if they had that they wouldn’t be there in the first place, would they. even then, efficiencies get to maybe 55% because turns out that these heat exchangers required for for professional stuff are huge and can’t be loaded on trailer, so they have to go with less

so it sorta gets them power short term, and financially it doesn’t look well long term, but maybe they know that and don’t care because they know they won’t be there to pay bills for gas, but also if these glorified gensets are only used during outages or otherwise not to their full capacity then it doesn’t matter that much. also gas turbines in order to run efficiently need to run hot, but the hottest possible temperature with normal fuels would melt any material we can make blades of, so the solution is to take double or triple amount of air than needed and dilute hot gases this way, which also means these are perfect conditions for nitric oxide synthesis, which means smog downwind. now there are SCRs which are supposed to deal with it, but it didn’t stop musk from poisoning people of memphis when he did very similar thing

* proenergy takes the same jet engine that GE does and turns it into PE6000, which is probably mostly the same stuff as LM6000, except that GE version is 51MW and proenergy 48MW. i don’t know whether it’s derated or less efficient still, but for the same gas consumption it would be 37.5%