SpaceX

<b>Estimating what building a 1-10 MW Solar Park on Mars would involve.</b>
IntroductionI thought it'd be interesting to get an estimate of what kind of challenge would be involved in developing, delivering and deploying a solar park at 45 N on Mars, which would generate the kind of power suggested by Elon Musk in the recent tweet.I will attempt to stick to real world products or which can be readily engineered (no breakthroughs required) and I will attempt to err on the side of being conservative.It should go without saying that this is entirely hypothetical and SpaceX might do something almost completely different. I hope only for a result that is in the right ballpark in terms of payload and deployment time. Like it's helpful to get an idea of what we are looking at: Multiple Starships crammed full of solar panels? Or a small fraction of the payload capacity of a single Starship?TL;DRPayload mass: 11 tPayload volume: 225 m3Deployment time: 2-3 weeks for 4 astronauts.The RequirementsFor the 10 MW nominal capacity I am assuming "A solar park that would be labelled as 10 MW if it were on Earth", the nominal capacity of a solar panel and generally the generation capacity of a solar power plant is referenced to 1000 W of sunlight on Earth and disregards any pesky reality like night time or clouds, this way of rating a solar powerplant is often complained about but it is both convenient and conventional.The general consensus on <a href="/r/spacex">/r/spacex</a> is that a propellant plant for refueling one Starship per synod (and providing life support for humans on the side) would consume on average 1 MW, it so happens that 10 MW nominal capacity is roughly the same as 1 MW real world generation on Mars: sunlight on Mars is about 50% as intense as at the surface of Earth, 50% of the time it is dark, 30% of the power during the day is lost due to sub-optimal sun angle, 20% is lost due to latitude and seasons, 25% is lost to dust in the sky and dust on the panels. The product of these factors is around 0.1. FWIW for single-axis tracking solar panels it's about 0.135 and for dual-axis tracking about 0.145, but for this analysis I assume fixed-tilt.So in summary, this solar park is 10 MW nominal, 1 MW actual average generation.Why fixed tiltJust rolling the solar panels out on the ground is tempting, as it allows using large rolls of flexible solar panel.The reason I'm not assuming horizontal panels is primarily one of latitude: The planned latitude for the base appears to be around 45 N. And Mars has an axial tilt of 25 degrees - which is almost the same as Earth's. If you live at around 45 N (or 45 S) on Earth you'll have a pretty good idea of how low in the sky the sun is during winter, in fact the sun will rise just around 20 degrees above the horizon. A fixed tilt panel at least doubles generation during winter and also increases it throughout the rest of the year. The exact tilt to use, assuming it is non-adjustable, can be optimized to maximize power generation over a year (essentially maximizing the generation from long summer days), or to maximize winter generation, or a compromise. A tilt which is equal to the latitude (i.e. 45 degrees) tends to be a reasonable compromise.Fixed tilt also ought to reduce dust accumulation, some dust will stick due to electrostatic forces but it does stand to reason that a tilted panel will accumulate less dust than a horizontal panel and be easier for the wind to clean.Furthermore, according to my analysis going with fixed tilt does not incur a large mass penalty compared with flat panels and the deployment time is longer but still reasonable.Single or dual axis tracking is outside the scope of this analysis, I don't believe the mass penalty for single-axis tracking would be prohibitive, but it is another point of failure and complexity and the efficiency improvement isn't as great as the difference between horizontal and fixed tilt.The Solar PanelsThe solar panels will almost certainly be custom…

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