Have been reading all of this and have a tremendous interest.
Starting here Wayne, because there is not enough (virtually none) effort to capture and make use of the "waste" steam/heat value.
Not nitpicking here, just trying to clarify. There is no "excess" steam/heat, just the used/exhaust steam from the generator turbines. This exhaust steam still contains a tremendous amount of usable heat if they are wise enough to make use of it as in your greenhouse example.
The problem is:
Once the steam exits the turbine, it is cooler and contains moisture droplets which would eat the blades of a "secondary/down stream" turbine, even though is still contains a lot of heat energy.
Further, it is not practical to try to "re-introduce/recycle" the exhaust steam back into the primary power generation loop due to the extreme temperatures and pressures involved. SOOOOO, it is quite often just exhausted and wasted in cooling towers as is the case for most if not all Nuclear Power plants.
Not an expert on this, but I guess going back, the costs involved in capturing this waste heat exceeded the economic gains of finding a secondary use.
New York City distributed the waste steam from the power plants throughout the city to heat buildings. I assume they still do, but have not seen anything about it in years ??
On Trades post, I have to go back to it so I don't mis-state what he said.
But here, I wonder how long "Industry" has had a view that NG was plentiful and cheap, and likely to remain that way ??
The development cycle can be long and expensive.
Wouldn't the companies that make most of their money from crude have a vested interest in maintaining that.
Didn't Exxon/Mobil just buy into NG ??
And, fact or fiction, remember the talk years ago of the oil companies buying up the patents on that "new and highly efficient" carburetor long long ago !!!!
I imagine that one has been de-bunked long ago. I suspect it should be pretty well understood just what you can get out of gasoline combustion no matter how you feed it to the engine !!!