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Complete Solar-Powered Hydrocarbon Production

At some point in the future mankind will have to cleans the atmosphere of harmful elements (carbon dioxide, etc.) and produce any required hydrocarbons from scratch.  The article below shows one element of this. Sustainability has to be a key element in the future.

An anonymous reader quotes a report from Ars Technica:

Carbon capture. Hydrogen production. Synthetic fuels. All of these technologies have been proposed as potential resources for dealing with the crises created by our carbon dioxide emissions. While they have worked in small pilot demonstrations, most of them haven't demonstrated that they can scale to provide the economical solutions we need. In the meantime, a group of European researchers sees the methods as part of a single coherent production platform, one that goes from sunlight and air to kerosene. Thanks to a small installation on the roof of a lab in Zurich, the team has been producing small amounts of different fuels using some mirrors and a handful of reaction chambers. While the full production process would also need to demonstrate that it can scale, the researchers calculate that the platform could fuel the entire commercial aircraft industry using a small fraction of the land in the Sahara.
[...]
Overall,
 the results are clear: The process can work, but it's not productive enough to matter in its current state, so a large portion of the paper considers optimization and scale. Optimization is mostly a matter of many little improvements, like the better use of waste heat to ensure all the necessary heat is provided by the solar reflectors. Other targets include better catalysts and more efficient means of storing the gasses between steps. Then there's a matter of scale. To fuel a daily round-trip flight between New York City and London, the researchers estimate, it would take 10 mirror farms directing sunlight at reaction chambers in an area that gets strong and consistent sunlight. That translates to covering around 3.8 square kilometers of the desert with mirrors. (For context, that's about a quarter of the size of California's Ivanpah solar facility.) Providing for all of commercial aviation's fuel needs would require taking over half of one percent of the surface of the Sahara Desert. And that means a lot of mirrors.

The researchers suggest we will likely see the sort of dramatic cost reductions seen in other renewable resources, including technologies like
 concentrating solar power. That mirror-based tech saw prices drop by 60 percent over a recent 15-year period. But it's questionable whether the sorts of price drops we've seen with photovoltaics are possible, given the large material costs of all those mirrors and their associated hardware, plus the maintenance costs of keeping them clean. The flipside is that concentrating solar power costs have continued to come down, and a lot of those savings could probably be applied to heat-driven chemistry like this. And it's possible that this basic concept -- solar-powered green chemistry -- could be adapted to produce fuels with a higher value than kerosene.

NREL Q1 2021 PV & Energy Storage Costs

The National Renewable Energy Laboratory (NREL) ]released its annual cost breakdown of installed solar photovoltaic and battery storage systems.

U.S. Solar Photovoltaic System and Energy Storage Cost Benchmark: Q1 2021 details installed costs for PV systems as of the first quarter of 2021. The link above will download the full report as a .pdf.

The report said that costs continue to fall for residential, commercial rooftop, and utility-scale PV systems by 3%, 11%, and 12%, respectively, compared to last year.

Some typical content:

As demonstrated in Figure 13, the kit for a 5-kW/12.5-kWh storage system costs approximately
$6,406–$6,662 with a total installed cost of $15,852 (DC-coupled) to $16,715 (AC-coupled).12
Also, Figure 14 (page 24) shows the cost of residential storage systems for different system
capacities.

NREL 1Q 2021 residential example

Worth downloading this report if you are interested in costs.

Pilot line for complete PV module recycling

A European consortium consisting of Italian energy agency Enea and the French Alternative Energies and Atomic Energy Commission, among other entities, has developed a plan to build a low-emissions pilot line to recover critical and precious metals such as silicon, indium, gallium and silver. The line will be designed to reintroduce new materials and new products into the production cycle

See the full pv magazine article for more detail.

Interesting Technology

An assortment of links to interesting information  

Semiconductor Nanowires Could Double the Efficiency of Silicon Solar Cells

A p/n semiconductor junction is not the only way of converting sunshine into useful electrical energy.  Light consists of a flow of photons of various energy levels (colors).  See this article-Solar Cells.  Nanowires on the solar cell surface can also convert sunshine into useful electrical energy.  This works because photons also have a wave function that can be harnessed. See this interesting article:Semiconductor Nanowires Could Double the Efficiency of Si Solar Cells