You are talking about solar panel manufacturing being an energy-intensive process. It is true that over 50% of the global production of solar panels happens in China, and most of the electricity used in the manufacture of those panels comes from burning coal. But there is no reason in principle why solar panel manufacturing could not be powered by electricity produced by non-fossil fuel based power sources (nuclear, solar, wind, hydro, geothermal etc).
China is going to move away from fossil fuels for electricity generation over time. Slower than it should, but it is going to do it. And just because China controls so much of that industry right now is no guarantee that it will continue to do so into the future.
https://spectrum.ieee.org/green-tech/solar/solar-energy-isnt...
It’s an illusion that renewables are replacing fossil fuels. The amount or renewables isn’t even replacing the amount of energy that demand is growing by, so we rely more and more on fossil fuels even as more “renewables” are trotted out as a distraction. This is just a sham death cult because people can’t accept reality. Conservatives have religion and liberals have technology they hope will save them. We are a species in denial.
The general idea you are referring to is the "life cycle greenhouse gas emissions" for an energy technology. This is a well studied field.
Information from the IPCC and the DOE seems to indicate that photovoltaics and wind have something like 20 times lower green house gas emissions than coal plants over the entire life cycle. [1][2]
And since the manufacture of PV and wind accounts for a majority of the greenhouse gas emissions associated with the lifecycle, the emissions will improve for this tech as the blend of energy used to power the manufacturing becomes "greener".
If you think that renewables "aren't even replacing the amount of energy demand is growing by", then you should advocate for additional construction of renewable energy rather than suggesting that they are a dirty technology—since the science we have suggests they are not.
[1] https://en.wikipedia.org/wiki/Life-cycle_greenhouse-gas_emis... [2] https://www.nrel.gov/analysis/life-cycle-assessment.html
>silicon metal is made from the reaction of silica and carbon materials like coke, coal and wood chips
https://www.workoutmilano.it/gold2/6774-silicon-metal-quartz...
> In order to produce a single (1) metric ton (MT) of silicon metal, raw material inputs of 2.8 MT quartz, 1.4 MT coal, and 2.4 MT wood chips are required and represent a 6.6:1 ratio of process inputs to outputs.
http://guntherportfolio.com/2010/03/making-silicon-metal-for...
One obvious difference – the technology to capture waste CO2 gas is clearly feasible in principle. We already have lots of research into capturing and reusing CO2 (such as from coal-fired power stations) [1], and we already have known industrial processes which use CO2 as input [2]. So, the issue here is really (a) more R&D to finesse the technology, (b) its application to silicon refining specifically (other CO2 emissions sources are more significant and hence receive more focus) (c) getting the economics right. (On the last point, emissions trading schemes may help.) By contrast, most of the physics community doesn't believe cold fusion is a real phenomena, and the small minority who think it is can't explain how it works. You are comparing a technology whose physics and chemistry is well understood, and which basically just needs productisation, with a technology where there is disagreement on whether physics even allows it to exist.
[3] seems a particularly interesting approach - conversion of CO2 gas to graphite. The graphite in turn could potentially be reused in the silicon refining (which needs a carbon source, not coal/coke/wood specifically). Most current methods of procesing CO2 turn it into chemicals such as methanol (CO2 + hydrogen gas), urea (CO2 + ammonia), etc, which while useful, I'm not sure you could actually reuse those chemicals in silicon refining
[1] https://en.wikipedia.org/wiki/Carbon_capture_and_storage
[2] e.g. https://en.wikipedia.org/wiki/Methanol#From_synthesis_gas
[3] https://www.nature.com/articles/s41467-019-08824-8
> This is what I meant about the left having a fantasy that one day technology will save us
I'm not sure it is really "the left having a fantasy". I know plenty of right-leaning people with solar panels on their roofs. (I even know global warming sceptics with solar panels on their roof.)
I think fossil fuel use is going to decline over time. That's already happening in a lot of countries. It's going to be a gradual process, and I think eventually it is going to happen everywhere, but some parts of the world (e.g. Europe, US) are going to be ahead of others (e.g. China, India)
Is there such a thing as "100% clean energy"? I don't know if there ever will be such a thing, but so what. If you look at tonnes of CO2 emitted per a kilowatt-hour, over the life of a generator, then a solar farm is going to beat a coal power station, even when you include the CO2 emissions from the construction and the manufacturing of the equipment. Sure, the solar farm won't be "100% clean" (zero lifetime emissions), but it doesn't need to be, it just needs to be significantly better than the coal power station.
In some countries, coal power stations are being replaced by natural gas power stations. Natural gas obviously isn't 100% clean – it still emits CO2 and other pollutants. But it is a lot cleaner than coal. It emits less greenhouse gases for the same amount of power generated. We shouldn't let the perfect be the enemy of the better.
I'm also a proponent of nuclear after my thermodynamics professor sat my class down and explained why solar is a dirty process to get up and running and biomass is not sustainable.
I think the potential is in advancement of nuclear power plant tech. The US is working with pretty old 20th century technology and there isn't much movement in the space that I know of probably due to fear.
Factoring in typical assumptions of population and economic growth, and the picture darkens further.
We simply don't have available biomass to power the present economy, let alone one with more people of net higher average wealth. There are reasons humans switched from renewable to nonrenewable energy resources. Unfortunately the practice is unsustainable on several fronts.
https://old.reddit.com/r/dredmorbius/comments/2cvap7/the_int...
http://www.eoearth.org/view/article/153031/
http://agroinnovations.com/blog/2007/04/27/the-photosyntheti...
https://web.archive.org/web/20120810132407/https://environme...
I especially recommend Jeff Dukes, "Burning Buried Sunshine" (2003):
https://dge.carnegiescience.edu/DGE/Dukes/Dukes_ClimChange1....