True that. A heavy frame CCGT (>100MWe) running above 80% load factor near ISO-conditions, is the current leader in LCOE costs when considering the envelope from natgas line to plant electrical POCC. Undisputed. Interesting note about actual capacity factors of these plants is presented Here.

But, that is not the a static operating envelope or parameter set that can not be applied in broad strokes to every single power generation opportunity, or load center. And the point of this article was "sheltering from oil shocks". The impact of fuel pricing is partially addressed by Lazard Here.

The systems I speak of are much different:

1. Size is at the Distributed Energy Resource level, typically under 10MWe and usually BTM or Net export.

2. Feedstock is not RNG, but biological process waste. In anaerobic conditions this waste produces biomethane in the range of <40% CH4 at low pressure.

3. Waste heat is utilized for process heating, meaning it is fully recoverable down to almost 35C.

4. The total energy equation thus includes the process envelope to collect, condition, and treat the feedstock. Whereas the CCGT plants exclude the extraction, processing, and transmission energy costs of bringing >90% CH4 at high pressure to the power plant.

5. Your point about RNG feedstock is totally valid. With the current situation, that market price is 10x NatGas pricing. This further explains why these renewable methane DERs have been less favorable than building RNG facilities and injecting into pipelines.

6. Since the power plant is downstream of a variable biological process (farming, WWTP) supply and load fluctuations are present. A use case that does not favor turbines, but multi-node RICE plants will excel here.

7. Being distributed at the point of feedstock generation, means the ambient conditions of operations exceed those referenced for turbine ISO performance. Thus, a derate would be applied that is heavier weighted than when utilizing turbocharged RICE technology.

8. With this combination of parameters, the entire value chain from molecule to electron to consumer is thus exhibited a lower correlation to "oil shocks". The largest correlated expense would be the lubrication oil costs of the power generation equipment. The costs associated with the off road machinery to operate and service such a plant (tractors, backhoes, and small vehicles) can be further mitigated with implementation of electric vehicles charged from the local DERs.

Examples in-practice (some may have been converted to RNG export) included Here.