from brave leo:
Kilowatt Hours for PV Silicon
The process of manufacturing photovoltaic silicon requires a significant amount of energy, particularly in the initial stage of converting silicon dioxide into metallurgical grade silicon (MGS). Producing 1 kilogram of metallurgical grade silicon requires 14-16 kWh of power.
This energy-intensive step is a crucial part of the solar panel manufacturing process, although the panels themselves generate far more energy over their lifetime than is consumed in their production.
i'm not sure what the ratio of weight to wattage output of the cells that are grown in a very hot oven over weeks, including that energy for producing all the dopants that provide the photovoltaic effect.
also, it doesn't specify how much over. because if it's only 2x its still a bad deal compared to a coal fired generator, or refined diesel and octane type fuels (and the propane and butane you get in the process, which is difficult to capture because of what i said about the problem of gas fuel storage).
i'm highly skeptical that it doesn't near as much energy again to grow the crystals after refining the silicon.
and like you point out, the problem is when it generates the power. that is entirely random. it's practical for satellites, where they can depend on a fairly constant power level based on the orbit, but down here you got clouds and smoke.
if you factor in, based on this theoretical 2-5x output per input, the cost of the batteries you need, and how frequently they need to be replaced, i'm pretty sure it drops back to very close or under unity.
wind powered water-gravity batteries would make way more sense, because other than maintaining the water level to sufficient for your energy input, you would have totally on-demand just by dialing open the tap.
the environmental damage and toxicity of lithium mining and battery production are factors they never mention, also. in fact, probably lead-acid batteries would be better because they are more durable, and the lead is easy to recycle, and toxicity-wise, pretty minimal risk of catastrophic issues. lithium, on the other hand, once it's refined into pure metal, is a severe fire risk, and will not stop burning until all of it is converted into oxide and carbonates.
so, yeah, in theory, great, solar panel is about 4-5x output as input. but the need for batteries destroys all of that benefit, at least halves it, probably worse, and using lithium, adds on top of that a serious fire risk that leads to airborne pollution from what burns with it.
i'd rather go with uranium. it's heavy enough that it at least doesn't spread that far if the meltdown is contained. and it's efficiency is higher and also can be dialed up and down on demand.
the point that there is more factors in the equation is another thing that never gets discussed in the slogans of the envirofascist misanthropic cult of government population control, and the fact that a huge amount of political power and especially military power (if you include police and judiciaries) in that, is extreme.
a free market would settle on the appropriate solutions. the centrally managed systems can't get even half way to an optimal solution because it's all about enriching the people at the front of the monetary spigot, at the expense of everyone else.
honest scientists and engineers wolud not pick the solutions we see now. they have use cases but they are not general purpose technologies.
i'd argue that they are just spinoffs of military research for purposes of perpetuating a constant state of fear in the population to use to manipulate them to continue to tolerate this intolerable state of affairs.