Quote from: nacnud on 02/19/2017 03:10 PMConcrete will be tricky on mars, no limestone.It could be marscrete. A material made from local resources, not limestone. It needs less energy to produce, too.The material is even better than normal concrete except it is not very resistant to water. Not a concern on Mars.
Concrete will be tricky on mars, no limestone.
Energy wise this sounds like it would be a much better idea to do focused solar rather than the trouble of PV arrays to electricity to heat.
Quote from: john smith 19 on 03/12/2017 04:20 PMEnergy wise this sounds like it would be a much better idea to do focused solar rather than the trouble of PV arrays to electricity to heat.Atmospheric dust scatters sunlight amazingly well. Even on a bright clear day on Mars, you can lose 30% of direct light. Concentrator-mirrors can't work with scattered light, but solar panels are barely affected. Additionally, solar panels produce general purpose electricity (obviously), which can be diverted to any use, especially in an emergency. Solar furnaces will be single-purpose dedicated systems, nearly worthless for backing up other systems.So, IMO, even with the loss of efficiency with solar PV, the net benefits vastly outweigh the costs.
Do high-temp solar furnace processing on Phobos?
Hmm, photovoltaics deployed on the surface of Mars will most probably be less complex than a system that involves flying back and forth between Phobos and the Martian surface.
Roll-out thin-film PV sheets (tied down to the Martin surface so they won't lift off when a cleaning dustdevil passes) are basically maintenance-free and highly dependable. I am quite sure they will provide the energy needed on Mars.
Thanks for your reply, John. However, I don't understand what the problem is. If you need more electricity for energy-intensive construction work you would just lay out more PV film, wouldn't you? It is not as if they lack real estate on the surface. Or is there a problem with having a lot of PV sheets generating electricity without "tapping it off"? Sorry, I just don't know.
Why not both? Mirrors to concentrate more sunlight into panels?
In contrast using solar concentrators (imagine or non imaging) may lose 30% due to dust scatter. That leaves 70% as available energy that can be used to process materials.
Can Nylon Be Made From Water, Sunshine and Plant Waste?— April 09, 2017Currently, many types of fabrics, including nylon, are made in an energy-intensive, unsustainable process that uses fossil fuel. Now, NYU Tandon School of Engineering Assistant Professor Miguel Modestino, of the Department of Chemical and Biomolecular Engineering, is proposing a method that eliminates oil from the equation, employing water, plant waste and solar energy to deliver a material identical to the nylon now widely used in the fashion industry and in other commercial applications.Modestino and his co-researcher, Sophia Haussener of the École Polytechnique Fédéral de Lausanne (EPFL), have garnered a 2017 Global Change Award of €250,000 ($267,000) from the H&M Foundation, the non-profit arm of the retailing giant. The first such initiative by a major member of the fashion world, the Global Change challenge attracted almost 3,000 applicants this year and aims to support early innovations that can accelerate the shift to a circular and sustainable garment industry, in order to protect the planet. The awards were presented in Stockholm, Sweden, on April 5.The researchers chose to focus on nylon because of the large market for the popular polymer, which they estimate to be more than 6 million tons per year, with a value of more than $20 billion. Their proposed process uses photovoltaic arrays, which generate electricity directly from the sun, to drive the electrochemical reduction of acrylonitrile (ACN) to adiponitrile (ADN) and hydrogen (H2), which will, in turn, be synthesized into hexanediamine (HDA), one of the existing precursors to nylon.Because ACN can be derived from plant waste, only sun, water and carbon dioxide will be required as inputs, and the new process will represent a new scheme for carbon capture, where greenhouse gases will be bound into the fabric, rather than releasing them into the air.
It can be fitted with a range of different tools, including a foam insulation gun, a welding attachment, a “thermoplastic extruder” that squirts out melted plastic, a glorified squirt gun, and even a simple bucket.