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Solar shingles have been around since 2005, and improved technology combined with serious tax breaks make them more affordable than ever. Solar shingles are often tied into the grid of existing power lines, which offers a backup at night or on rainy days.

Assuming our maths is correct (not a safe assumption so please check it) and using a $4500/kW estimate, it would cost just shy of US$88 trillion to build enough new nuclear plants to reach 20 TW capacity worldwide. By way of comparison the total worldwide GDP in 2014 was about US$78 trillion ( source ). EL has suggested these plants need to be built over the next few decades so presumably that US$88 trillion would be spread over that time period which would mean spending roughly 1/25 (give or take) of the world’s GDP on this project each year for the next 30 years.

Again, I’m not trying to say we should ignore proper cleanup and decommissioning. The prices being quoted include such things. What I am pointing out is that every energy source needs to be refurbished and rebuilt after its lifetime, which means that maintaining 10 terawatts indefinitely would mean a recurring constant upkeep cost. I was merely pointing out that this need not continue indefinitely into the future. Maybe only for about a century. Maybe half a century. Depends on the numbers, assumptions, etc.

IIRC, the energy usage per capita of the US is around 2 to 2.5 kw. Whereas California and most of Europe are round 1 kw. I think that aiming for 1 kw per person is a reasonable number. However, if we aim for that number, that means 1 kw 10 billion people = 10 terawatts right there, and again for comparison today we have about 2.3 terawatts of electricity production, and according to someone upthread, only about 0.5 terawatts nuclear electricity production. This also assumes that we get the US to go to reasonable energy efficiency standards like Europe and California.

Again, as I mentioned above, the only catch is that this process will require a ginormous amount of energy. At a first approximation, we’re simply reversing the burning process, and so the energy required is approximately equal to the energy that we got out burning the fossil fuel in the first place. To a first degree of approximation, we will need 10 terawatts of power running for several decades. For comparison, wikipedia tells me that currently we only produce about 2.3 terawatts of electricity worldwide. This number is huge, but it’s not impossible. We need to build a large (1 GW) nuclear reactor, every day, for the next few decades. This is not impossible.

Such a system exists. Figure 1 is a picture of one the four Ultra Large Crude Carriers my company built in Korea in 2000 to 2002. These ships, Figure 1, are capable of carrying 440,000 tons of oil at 16 knots for 25,000 miles. They are the largest double hull tankers ever built. Each one of these ships required 67,000 tons of steel much of it curved and some of it double curved but only 700,000 man-hours of direct labor. Over half of this is in outfitting. A good yard will require about 5 man-hours to cut, weld, coat, and erect a ton of hull steel. The build time was less than a year. The cost was 89 million dollars.

Block construction not only creates order of magnitude improvements in productivity, but it also produces striking improvements in quality. Very tight dimensional control is automatically enforced. Extensive inspection and testing at the sub-assembly, assembly, and block levels is an essential part of the yard’s productivity. Inspection at these levels is easy. Defects and faults are caught early and can be corrected far more easily than after erection. In most cases, they will have no impact on the overall project schedule. A decent tanker, operating in a very severe environment, will have an availability of over 95%.