Such an analysis is not the correct way of looking at the matter.

You write that it would take “162 years to convert the entire 1/3″…but what power plants do you know of that are 162+ years old?

Power plants don’t get replaced at a particular rate because someone says, “We should replace one plant per day.” They get replaced because they are no longer economically competitive…whatever the reason.

So the rate of replacement might be 1 per day, or 5 per day, or 10 per day, or more.

“Any guesses on when the power plant conversion rate will become positive, and a what rate it will occur?”

This is also not the correct way to look at the problem. Existing power plants will not necessary get converted to “carbon-free energy production.”

The proper questions are, “Will they get converted to lower-CO2-emitting technologies?” And, “Will the total CO2 emissions from power plants worldwide go down?”

The answer to that first question is that new plants will almost certainly be lower-CO2-emitting than the plants they replace.

But the answer to that second question is much more difficult, since worldwide electricity production can be expected to rise for the forseeable future, particularly in China, India, and other rapidly developing countries.

So perhaps that second question would be answered that CO2 emissions from power plants in developed countries (e.g. U.S. and OECD Europe) will probably reach a peak and head downward in the next decade or so, if they haven’t already. Whereas CO2 emissions from power plants in developing countries can be expected to continue upward at least for the next 20-30+ years.

“Will it occur at all?”

Do you mean, “In the year 2100 or 2200, will there still be fossil-fueled power plants?” It seems very unlikely to me.

If you could replace 1 big (1 GW) plant per day, the conversion would take only 7 years. Of course, that’s a thousand big wind turbines a day (more if you account for generation instead of capacity). For comparison, the US made 200 combat aircraft per day in 1944, and the global auto industry makes 170,000 cars and light trucks per day, so the job is far from impossible.

I find it easier to look at it in $. The 2500 GW of global fossil generating capacity represents a $2.5 trillion asset at $1/watt. With a plant life of 40 years, its natural turnover rate is $60 billion/year – peanuts – and similar to the annual increment added to grow capacity.

The challenge comes if new plants are, say, $5/watt. However, if electric rates reflected those kinds of marginal costs, you’d expect to see a lot of conservation in the long run, and suddenly the task would be much smaller.

In other words, can’t simply replace the existing capacity. We need to double it while we are replacing it.

Don’t forget, the urgency of the situation has evaporated as temps are cooling so far this century.

Research of this scale always has unexpected benefits. Maybe any new taxes should be dedicated to increasing the power of the hardware so climate scientists can decrease parameterizations, rather than (as politicians are undoubtedly scheming) just going into some general fund; or as brokers are scheming, going into some trading scam.