Almost everybody today agrees that it would be really smart (if not vitally essential) that we reduce the amount of fossil carbon we release from giant, tupperware-geological structures deep inside the earth. But how would we accomplish freeing ourselves from coal, petroleum, and gas while maintaining a dependable flow of electricity?
Mainstream environmentalists currently advocate for generating energy from wind turbines and solar arrays, whose energy comes more-or-less directly from the sun. With solar photovoltaic, solar thermal, and wind turbines we can produce electricity without generating any carbon dioxide (once these devices have been manufactured and placed on a field or ocean somewhere). Unfortunately, one issue with these technologies is that the energy is intermittent. With the wind dying down and the Sun being obscured by clouds or the night, these devices only actually generate electricity a small minority of the time, let’s say generously 30% of the time.
Unless one is a caveman or total hippie or something, one would generally like to have access to electricity 100% of the time. This generates a problem with “zero-carbon” energy from wind and solar: what will produce the electricity the other 70% of the time to account for the interrupted power supply ?
The best answer we currently have is special natural gas turbines that can be turned on and shut off quickly. Most turbines in gas power plants, use a Combined-Cycle Gas Turbine (CCGT) to generate electricity from natural gas which makes an impressive 60% efficiency. However, CCGT plants take too long (about 40 minutes) in powering up to compensate for the lack of electricity resulting from the wind dying down or a cloud passing over. Therefore we must couple the wind and solar generators with Natural Gas Combustion Turbines (NGCT), which can be powered up in 10 minutes but only achieve 35% efficient.
Looking at the math behind these two alternatives, it becomes painfully apparent that running a CCGT generator (at 60% efficiency) 100% of the time burns significantly less gas than running a NGCT (at 35% efficiency) 70% of the time, even if the other 30% coming from wind and solar was absolutely free. In fact in a 1,000 megawatt renewable-30%/NGCT-70% coupling, we could postulate that at any given time we would use about 2400 units of natural gas; whereas in a CCGT-100% gas plant, we would use about 1700 units of gas. Thus, if we are looking to reduce carbon emissions, it would be smart of us to avoid building wind and solar plants altogether! Strange but true! [Reference video]
Our most promising but oft demonized method of generating zero-carbon base-line energy is by building slowly shifting toward better-designed nuclear power plants. Our current nuclear plants we humans operate are analogous to driving Ford Model T cars, when we could be driving a 2014 Honda Odyssey or some other paragon of modern engineering and efficiency, except this car would be impossible to crash and consume the waste of Model Ts for fuel! Please take time to learn more about the possibilities of modern nuclear reactor design using thorium molten salt fuel and molten salt coolant.