This is where the gun begins!

Exactly. We already have the revolutionary tech.

Well, the prices are dropping so quickly than you'd be better off waiting a few years before buying.

At this point they're also cheaper than roof slate. If you're buying in bulk, it's not far off most decent roofing options for a carport.

Pretty soon, we'll be building everything out of solar panels and we still won't be able to use all of them.

We have a huge fusion reactor up and running 5head look up

But within 50 to 100 years fusion might become the best energy source, might help power the whole "such CO2 back ups of the atmosphere and store it" plan.

Sadly, that is pretty unlikely. The problem is in the physics of fusion.

Fusion of course works by fusing light atoms into heavier atoms. This requires enormous temperatures, enormous pressures and preferably both at the same time. This is difficult to achieve on earth, and all known methods require enormous amounts of energy. So using fusion as a power source requires that the fusion reaction outputs more energy than you put in. This means you need a fuel source that fuses as easily as possible, and releases the most energy possible. How easily a nuclear reaction occurs is measured by the nuclear cross section, the higher a cross section, the easier the reaction is.

Out of all the possible options, by far and away the easiest is Deuterium (D) + Tritium (T). Its cross section in optimal conditions is a full 100 times greater than the runner up (D+D). So a plasma of D+T is going to output approximately 100 times more fusion energy per second than a D+D plasma, which is huge when it takes so much energy to keep the reaction going. Building a viable D+D powerplant will be a full 100 times harder than an equivalent D+T reactor. Which is why every single serious proposal for a fusion powerplant involves D+T fusion. You can basically ignore anyone who starts talking about Helium 3 fusion or p+B fusion. All other reactors are orders of magnitude harder than simple D+T and we can't even do that right now.

However D+T has some severe drawbacks as well. D is easy to get, you can get it from water and it is quite abundant. T however is radioactive and decays in 11 years. Which means there are no natural sources of T, the only source of T right now is from nuclear reactors, and worldwide Tritium production of every single nuclear power plant in existence isn't enough to fuel even a single fusion reactor. Solving Tritium production is a major problem in current day fusion.

The current idea is to surround the fusion reactor with a blanket of Lithium. Lithium has the handy property of falling apart when hit by a neutron, and the decay products have a 50/50 shot of creating Tritium. This by itself is not enough, since each D+T reaction only produces 1 neutron, and even with a perfect Lithium blanket that one neutron will only produce half a T to feed back into the reactor, so the whole thing fizzles out quickly. But luckily Beryllium has a fun habit of decaying into 2 helium nuclei and 2 more neutrons when hit by a neutron. So it acts as a neutron doubler. By mixing the right ratio of Lithium and Beryllium in your blanket you can make a fusion reaction produce its own Tritium supply.

However, this does mean that you are now burning 3 fuels. Deuterium, Lithium and Beryllium. Deuterium is the easy one as mentioned above. Lithium isn't ideal since we also need it for batteries, but supplies are high enough that we can spare some for fusion reactors. Beryllium is a big problem tho. Beryllium is rare, very difficult to refine, and as a result really expensive. And we need huge amounts of it to build fusion power plants. ITER on its own, consumed a full 20% of GLOBAL yearly beryllium production. We can crank up worldwide production a bit, but a hypothetical nuclear fusion rollout is going to be severely bottle necked by Beryllium production, and there are no alternatives to work as a neutron doubler...

So even if we solve the engineering challenges associated with fusion, it'll run straight into a wall of resource scarcity and economics. Even worse than conventional nuclear runs into that wall.

We should of course still research fusion. We need to learn more about high energy plasma physics, and maybe in the far future we can use that knowledge to make fusion power plants that run on D+D. And there may be some rare situations where a D+T fusion reactor makes sense (Space travel beyond Jupiter?). But I don't expect fusion to be relevant for earth based electricity production for a very long time. Possibly never, since a full on Dyson sphere beaming down energy is probably easier and more effective.

You mean it is an unnecessary luxury that Li batteries are light.

Yeah, so Tesla megapacks are only 80,000 lbs. It'd be nice if we had a heavier option 😉

That's complicated to estimate : you have to know where and when the panels will be used, for how long and whether it replace other means of generation or adds up to it.

The evolution of the fabrication emissions, on the other hand, is very straight forward and give basically the same info since fabrication is the bigger share of the emissions related to solar panels.