Starpath rebuilt space solar panels from a clean sheet

Transcript

Transcribed by machine (Whisper) from the episode’s audio, so a word may be off here and there.

1. 21:27

   space solar panel by like at least an order of magnitude 50 times yeah 50 times can you walk me through why space solar panels used to cost so much and what you were able to change yeah um so i'll answer the question directly first because i tend to like give like lots of roundabout answers um which is basically just we we we rebuilt it from first principles so long time ago 10 years ago space solar panels used to be made out of these like super rare earth materials built into wafers it would cost hundreds of dollars a watt so we talked about a five dollar a watt data set okay a space solar panel from 2010 would cost you 300 bucks a watt maybe even a thousand okay so like ridiculous sums of money and they're made this way because i don't know like some scientists discovered that if you made it this way it'd be super super reliable and the volumes were low

2. 22:20

   enough that nobody cared how much they cost this this went on for a long time uh where the volumes were were were very low and people tolerated high cost because their end customer might have been the military or maybe they were doing you know a demo mission for a satellite that they planned to scale but hadn't scaled and so didn't care about the unit cost of the demo and this went on 2010 through 2020 maybe even 2023 2024 um and we basically said like okay what are the materials like the minimum set of materials that you need to make a space solar panel and uh worked completely from first principles up to try to produce a solar panel out of those materials so like we didn't say like how is the old panel made and what about it is expensive because the answer is everything like every single component like you can't even buy

3. 23:09

   one you know you can't even buy like the plugs okay uh for for a price that makes sense and we thought about every single material so so didn't look at the old one and say how we could make it cheaper but said okay given that we have this cost target and scale target that is driven by the need from data set can we invent a solar panel from first principles around material a material set and a manufacturing process that is both cheap and scalable so the short answer is we started from a complete clean clean sheet and it turns out that actually a lot of things are solar panels like believe it or not the led in your phone like like when you turn your phone flashlight on if you shine a bright enough light at that thing it's a solar panel too it's just not a very efficient one so a lot of materials that make solar panels and the ones that

4. 24:00

   people were using for space were just not the right ones. Now, it's not like we didn't run into challenges along the way. There is an immensely long list of reasons why solving a problem like this wasn't and isn't trivial. The only thing that's true about now that wasn't true about whatever, 2010 or 2020, is that in 2010, it looked like you needed to ship the size of a small schoolroom, you know, like a school classroom's worth of solar panels. Like imagine a school classroom and, you know, laying a bunch of solar panels on the floor and filling it up. Like that was the annual volume. I mean, maybe getting the math like a little bit wrong here, but that was like roughly speaking, the annual volume of solar panels for space in 2010 or something like that.

5. 24:42

   And now it looks like the annual demand for solar panels in space will be like, you know 50 000 football fields a year um and so because the demand is so much bigger the incentive to make the cost lower is so much higher and the incentive to develop new processes and invent new materials and test those materials and um is extremely high so before we go into the actual solar panel we need to talk about the two types of cost a solar panel for space has and it's quite simple the first is the actual cost so how much it costs to make and plus markup how much we sell it for which is a really really compelling price a price that works for a data set that costs five dollars a watt okay so we list it for fifteen dollars but we sell it for a lot less than that if you buy a lot of volume way way like an order of magnitude less the second is the cost

6. 25:41

   of launching it okay so the heavier it is the more it costs to launch in fact earlier we were talking about how a hypothetical 200 kilowatt class data sat might weigh just one metric ton um if you take the solar panels off of for example a starlink satellite the solar panels alone will weigh about one metric ton for a 200 kilowatt class satellite maybe a little bit more i actually don't know because i don't work at spacex and i don't have their data, but roughly speaking, that's about true. So to make the platonic ideal best and cheapest solar panel that delivers the lowest levelized cost of electricity in space, you need both to be extremely cheap to manufacture. So it can't be made out of rare earth materials. It can't be made out of things that are in short supply. It has to be made out of common materials.

7. 26:31

   And it can't be made out of any processes that are exquisite or challenging or extremely high temperature or require like very very precise instrumentation without revealing too much because i can't i can't you know i can't i'd love to i'd love to just be like okay step one step two um i can't talk about the exact recipe but um we when we started we asked ourselves like okay are there other optoelectronic devices so that the broad umbrella term for for things that are solar panels and led lights and stuff are optoelectronics are there other optoelectronic devices that meet the requirements we have, which are that it's extremely like dirt cheap to manufacture, like negligibly cheap to manufacture, meaning it's made out of super commonplace materials, and it's made out of materials that are either printed or deposited or in some capacity

8. 27:20

   ultra, ultra thin. It turns out that there is, and it's called an OLED. An OLED is an organic light-emitting diode or a light-emitting diode display. And everybody maybe hasn't heard the term but has certainly used one because just about every iPhone uses an OLED display as a screen on the front. So the screen of an iPhone is an OLED display. And an OLED display is made using most of the same processes as our solar panel. So one of the funny terms that I like to use is to describe the solar panel as an OLED, an organic light-absorbing diode, because it is a diode, But it is light absorbing and it is manufactured very much like an OLED display, which is very, very cheap.

9. 28:00

   So, the solar panel is really like a cheaper and light-absorbing optimized version of an OLED display. And we know that it is roughly as cheap as it can get because the materials that it uses are absolutely commonplace materials. Like there are materials that if I told you the names of all the materials, you could go online and buy them all in one day for a few hundred bucks and have them tomorrow.

10. 28:26

    Like they're not like we're not nothing from like, you know, like Africa or, you know, some weird like every single ingredient can be bought in every single country can be made in like hundreds of countries in the world. Super commonplace materials. the processes are also very simple and we know that it is the absolute thinnest that it can be because if it were any thinner it would reach a limit of thinness where it would be physically impossible for it to be anything but transparent in other words it is so thin that if it were thinner it would be see-through and something that is see-through is not a solar panel by definition um so if you guys want to take a look at it i have one here um this is what it looks like and um you can see it's like you know roughly speaking as thin as a piece of paper this one is a little bit thicker than a piece of paper um by about 20 percent

11. 29:20

    and um it's unbelievable i this is a is a piece of paper that you can roll up um and it generates