Space Mission Tests NREL Perovskite Solar Cells
Article courtesy of NREL.
by Wayne Hicks
On a clear night, Kaitlyn VanSant will be able to watch her work whiz by. Knowing the success of her project, however, will have to wait until her tiny, temporary addition to the International Space Station returns to Earth.
“My family and I have definitely been looking up at night more frequently,” said VanSant, who earned her doctorate from the Colorado School of Mines in materials science last year. Now a postdoctoral researcher with NASA, VanSant holds a unique collaborative appointment at the National Renewable Energy Laboratory (NREL).
The pairing of NREL and NASA continues a long-standing alliance between solar power and space. Specialized photovoltaic (PV) panels turned to the sun have been used to generate electricity for Mars rovers and space probes, but the manufacturing costs of these high-efficiency solar cells are too high for use on Earth. Researchers at NREL are testing ways to bring those costs down for terrestrial applications and transforming how PV technologies could work in space as well.
The latest test will evaluate the potential use of perovskite solar cells in space and assess the durability of materials used in those cells. VanSant worked with Ahmad Kirmani, Joey Luther, Severin Habisreutinger, Rosie Bramante, Dave Ostrowski, Brian Wieliczka, and Bill Nemeth at NREL to prepare the perovskite cells and materials. Eight of these samples are scheduled to launch to the space station in August and another set of 25 samples will be launched in the spring of 2022. The samples, each of which are a square inch in size, are part of the Materials International Space Station Experiment (MISSE) program and will be fastened to the outside of the orbiting platform.
The International Space Station (ISS) serves as an orbiting research laboratory and observatory that conducts scientific experiments in a range of fields that include astronomy, physics and materials science, to name just a few.
“We get to prove very nascent technologies in such a way that we don’t fool ourselves by simulating the space environment on the ground in a vacuum chamber, for example,” said Timothy Peshek, an electrical engineer in the photovoltaics group at NASA Glenn Research Center in Cleveland and VanSant’s postdoctoral adviser. “This is the real-world operation.”
With approval in hand to return PV experiments to the space station, Peshek put out calls for researchers who might want to take part. Adele Tamboli, a researcher in the Materials Physics research group at NREL, welcomed the opportunity, and introduced Peshek to VanSant.
“Partnering with the National Renewable Energy Laboratory just made a lot of sense,” said Peshek, himself a former post-doctoral researcher at NREL. “They had the facilities and abilities ready to go on day one.”
This perovskite sample is in the intermediate crystal phase and about to be placed on a hotplate to fully crystallize. Photo by Dennis Schroeder, NREL
Solar power on Earth tends to be generated from silicon modules. Other PV technologies, such as those used in space, rely on materials from the III and V columns of the periodic table and are dubbed III-V cells. Scientists have experimented with stacking a III-V cell atop a layer of silicon to increase the efficiency of capturing sunlight to convert to electricity. By itself, the most efficient silicon solar cell is about 26%, when measured under the typical terrestrial solar spectrum. (The solar spectrum is different on Earth and in space.)
Tamboli was among the research group that set records in 2017 for III-V cells on silicon, including a triple-junction cell with an efficiency of 35.9%. She, along with VanSant and staff scientist Emily Warren, would later propose that these types of cells could find a use to power satellites in a low Earth orbit. Before that could happen, the cells had to be tested in the extreme conditions of space.
If the moon is a harsh mistress, space itself can be equally cruel. Equipment is subjected to extreme swings in temperatures and bombarded by solar radiation. When the ISS moves behind the Earth and away from the sun, the temperature plummets to 250 degrees below zero Fahrenheit. Emerging into sunlight spikes the temperature to 250 degrees above zero.
“That’s harsh,” Peshek said. “That’s a pretty brutal environment.”
“Radiation damage is a factor,” said Warren. “Our record cell was gallium arsenide on silicon, and the one that we sent up is actually gallium indium phosphide on silicon. That was because we know that those materials would be more radiation tolerant.”
SpaceX’s cargo re-supply spacecraft carried NREL’s III-V-on-silicon solar cell to the ISS in March 2020. VanSant, whose Ph.D. research centered on III-V-on-silicon tandem solar cells, worked with Michelle Young and John Geisz at NREL to fabricate the prototype cell for the MISSE project, and watched a broadcast of the rocket launch carrying it into space.
“I watched it with my two daughters,” VanSant said. “They got a real kick out of it. I mean, you can’t really watch a space launch without just being completely fascinated. Nobody can be blasé about a space launch.”
The prototype spent 10 months affixed to the exterior of the ISS before being returned to Earth in January.
“The post-flight analysis of the cell gives us the opportunity to study how we want to evolve the design and to improve it for performance and to see whether it’s realistic that this could be a technology for providing power in space,” VanSant said.
Now she is playing a waiting game for the perovskite solar cells and materials, which are expected to spend six months on the ISS. The process is not a straight shot into space. After NREL, the cells are shipped to Alphaspace, a Houston company that prepares the samples for operation on the MISSE platform and arranges the launch of the experiment aboard a SpaceX flight.
Perovskite solar cells are grown using a mixture of chemicals, and notable for a rapid improvement in how efficiently they are able to harness sunlight for energy. Ongoing experimentation involves readying perovskite cells for commercial use. The early perovskite cells degraded too quickly. Progress has been made but there is still work to do.
“It’s a real interesting problem,” Peshek said, “because these cells are notorious for having degradation problems. But the reason they degrade is because of moisture and oxygen. We don’t have to worry about that in space.”
Earth-bound experiments conducted in radiation test facilities demonstrate perovskite solar cells are surprisingly tolerant to radiation, said Joseph Luther, a senior scientist at NREL, co-adviser on the project, and an expert in perovskite technology. “They are very thin, and so that helps a lot. Most of the radiation just goes right through them. Silicon, relative to perovskites, is hundreds of times thicker. It’s also very cheap due to the production scale and is awesome for terrestrial PV applications, but in space it’s so thick that when radiation is impinging on the surface it gets absorbed and it damages the cell, causing problems.”
Lightweight perovskite solar cells would fit with NASA’s ongoing mission to reduce the price for putting a payload into orbit, from about $10,000 per pound today to hundreds of dollars a pound within a quarter-century.
“We’re very interested in trying to match the efficiency of the III-V solar cells, but do it in an extremely lightweight cell design,” Luther said. “Perovskites can be deposited on plastics or metal foils and things like that, which are comparatively lightweight.”
The efficiency of the solar cells was measured before leaving NREL and will be measured again upon their return. Both the cells and the component materials of the cells will also be characterized before and after flight, with imaging expertise provide by Steve Johnston. How well the perovskite cells and materials survived their trip will be immediately apparent. Lyndsey McMillon-Brown, a research engineer at NASA Glenn Research Center and principal investigator on the effort to bring working with Peshek on bringing perovskites to space, said a color change offers the first clue.
“The desirable phase for a perovskite solar cell is a black phase,” she said. “The film is jet black. However, when these things degrade, they turn into a yellowy mustard color. So we’re hoping to see black films upon their return.”
The lessons learned from the time the perovskites spend in space could help with the technology terrestrially. “Some of the things that we’re facing in space are extreme, like extreme temperature cycling, extreme UV exposure, but when you’re here on Earth you still have UV exposure and you still have temperature cycling,” McMillon-Brown said. “It’s just not as rapid and frequent. We’re still thinking that our lessons learned and our findings will apply and help make perovskites more marketable and gain a bigger commercial market share here on Earth, too.”
While waiting for the return of the perovskite samples, VanSant receives a regular reminder of the ongoing work. She signed up for text notifications about when the ISS is visible overhead. When the time is right and her 7- and 9-year-old daughters are awake, they try to spot the space station.
“In addition to watching the ISS go by in the night sky, we have also watched NASA’s video footage from cameras outside the ISS that show the Earth passing by as the ISS orbits,” VanSant said. “The launch of these cells has been a great reminder to look up into the night sky, but also an opportunity to see things from a completely different perspective.”
Courtesy of NREL.
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In what appears to be a first of its kind, a new law was just enacted in Arizona that seems to have swept up some electric bicycles in an effort to outlaw kids operating off-road vehicles.
Arizona Governor Katie Hobbs has just signed into law Arizona Senate Bill 1567, which focuses on two key issues regarding off-highway vehicles (OHVs). The new law makes it a criminal offense for anyone to operate an OHV while consuming or possessing an open container of alcohol, and it also aims to prevent children from operating them by requiring a valid driver’s license and driver training. The former seems like a good idea, but it’s the latter that could pose a problem for kids riding recreational e-bikes.
The issue is the way Arizona defines OHVs. As stated in the new law, “An OHV is a motorized vehicle that is operated primarily off of highways and that is designed, modified or purpose-built primarily for recreational nonhighway all-terrain travel. An OHV includes a tracked or wheeled vehicle, utility vehicle, all-terrain vehicle, motorcycle, four-wheel drive vehicle, dune buggy, sand rail, amphibious vehicle, ground effects or air cushion vehicle and any other means of land transportation deriving motive power from a source other than muscle or wind.”
The legal definition of a “highway” is just a public road or street, not the colloquial highway we think of as high-speed roads. And while many e-bikes are designed for use on public roads, there are plenty of others, such as electric mountain bikes and trail bikes like Sur Ron-style light electric dirt bikes, that are obviously designed for non-road use. In Arizona’s broadly defined OHV category, technically these electric mountain bikes and other similar e-bikes could be swept up in the category of “transportation deriving motive power from a source other than muscle or wind,” i.e., a 250W to 750W e-bike motor.
In the US, electric bicycles are not regulated as motor vehicles at the federal level, but instead as consumer products just like all bicycles. However, Arizona’s state laws go further, painting with a broad enough brush to include some electric bicycles in the category of OHVs. While e-bikes designed for road use such as commuter, cargo, utility, and other road-going styles are likely safe as they are not considered “designed, modified, or purpose-built primarily for recreational nonhighway all-terrain travel”, there are several types of e-bikes, light electric trail bikes, electric mini-bikes and others that are certainly designed primarily for off-road all-terrain travel.
The new law, which was largely intended to prevent children from operating ATVs, side-by-side UTVs, and other similar off-road vehicles, lays out the penalties for underage violators operating an OHV in the state without a valid driver’s license.
For violators under 12 years old, the citation will be issued to the child’s parent or guardian. For violators between 12 and 15 years old, the citation can be issued to either the child or their parent/guardian.
Not only is electric mountain bike becoming a popular sport among teenagers, but there are even models such as the Specialized Levo SL Kids that are specifically designed for younger riders with smaller frames and reduced power.
Furthermore, even adult electric mountain bike riders could be impacted by this law if they don’t possess a valid driver’s license and haven’t completed Arizona’s upcoming OHV safety course.
Electrek’s Take
I’m not a lawyer here, but it seems like the law should have been crafted with a bit finer legalese to prevent this kind of bycatch from such a wide net. Unless Arizona’s goal was really to require a driver’s license to ride an electric mountain bike through a park, then someone screwed the pooch here. Sure, there have been sporadic e-bike bans before, but I don’t think the bill’s authors intended for this to apply to electric bicycles.
I’ve already heard from Arizona parents of kids who ride and who are working to get the law overturned or updated. With any luck, the state issues a clarification on the law to exclude off-road e-bikes or minibikes, many of which are popular with children as a common outdoor activity in the state. Without it, riding electric mountain bikes before getting a driver’s license is effectively illegal in the state of Arizona, at least unless you keep your fancy new eMTB on the pavement and tell the cop that it’s just a commuter with really good suspension.
via: ABC 12News
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The Pike’s Peak International Hill Climb is in progress, and several EVs which set out to post new records have done so today, with the Rivian R1T and Ioniq 5N both claiming records, and the Ford SuperTruck being the fastest vehicle up the hill on the day.
The Pike’s Peak International Hill Climb is one of the longest-running races in the world, being held 102 times since 1916.
It’s a famously difficult race, starting at an already-high 9,390ft (2,862m) in elevation and finishing at 14,110ft (4,300m), with an average 7.2% vertical grade. Until 2011, the track was largely unpaved on dirt or gravel roads, and it is not uncommon for cars to leave the track and crash into the woods or, worse, end up tumbling down the mountain. The race is also commonly stopped by rain, snow, fog, or other inclement weather of the type you commonly get at the top of mountains.
In particular, the high altitude nature of the race (which earned it the nickname “Race to the Clouds”) has always been difficult, because at high altitudes there is less oxygen, which means less complete combustion of fuel. This means that gas-powered race vehicles need to have incredibly oversized engines to do well.
That difficulty does not apply to electric vehicles since EVs don’t need oxygen for combustion, so for years EVs have overperformed in the race. Currently the all-time record for the 12.42-mile (20km) hillclimb is 7:57.148, set by the Volkswagen ID.R in 2018. And this year, an EV (Acura ZDX) served as the pace car for the first time.
There were 3 notable electric entries this year: the new higher-powered Rivian R1T Ascend Quad Max in unmodified form, the Hyundai Ioniq 5N in both stock and modified specs, and the bonkers heavily-modified Ford F-150 Lightning SuperTruck. (All vehicles do have seats stripped from the interior and roll cages/fire extinguishers added for safety purposes, but this doesn’t change total vehicle performance much due to the weight of the roll cage).
Last year, Rivian set the record for production trucks, gas or electric, with a 11:23.983, also putting it ahead of past runs by the likes of Faraday Future and a Tesla P90D. But it wasn’t an electric production record, as that was held by a Model 3 Performance with an 11:02.802.
However, with the R1T’s 190hp power boost over last year’s model, Rivian was hoping to gain some time – and boy, did it.
Driver Gardner Nichols managed to set a time of 10:53.883, shattering last year’s time by half a minute, setting a new record for any production truck, gas or electric, and even beating the 2018 Model 3 Performance by about ten seconds (though the new Model 3 Performance hasn’t run up the hill yet).
In fact, the R1T’s time would have been an overall record for unmodified electric vehicles – and even was that record, for a few minutes – until the next car up the mountain, the Ioniq 5N, came in 4 seconds faster.
Hyundai ran the 5N in two classes, aiming for both modified and unmodified records (one of its four vehicles had a crash in practice). Immediately after the R1T finished, Ron Zaras set a 10:49.267 in an unmodified Ioniq 5N, setting the record for electric production vehicles.
Unfortunately the 5N just barely missed the record for production SUV – currently held by the 2018 Bentley Bentayga at 10:48.902, only 3 tenths ahead over the course of this 12.42-mile track. If only Zaras hadn’t had that second donut this morning…
And in the modified category, the Ioniq 5N TA (“Time Attack”) spec, which carries over the stock powertrain but has some software tweaks for more power and big wings on the front and back, was piloted by Dani Sordo to set a 9:30.852, which is now the fastest electric modified SUV up the mountain.
While the R1T was the fastest unmodified truck up the hill today, it wasn’t the fastest truck overall. That honor goes to the 1,400hp Ford F-150 Lightning “SuperTruck,” continuing the long tradition of silly Pike’s Peak vehicles with gigantic wings.
The SuperTruck set the fastest time of the day, with an 8:53.553, the only vehicle to go sub-9 and more than ten seconds faster than the next-best finisher. And that was after the vehicle had an unexpected shutdown in the first sector, coming to a complete stop and needing to be repowered, losing almost half a minute in the process.
As a result, it didn’t set a record, as last year’s Ford SuperVan, a similarly-modified Ford Transit Electric, set a time of 8:47.682. That vehicle still holds the “Pike’s Peak Open” class record, and both were piloted by Romain Dumas (who also holds the overall record in the VW I.D. R).
While we’re somewhat jumping the gun on this article since the race is still in progress (you can watch here), it’s unlikely that any other cars will beat any of these times set. The SuperTruck had the fastest qualifying time by a longshot, and there are no remaining electric or production truck-class vehicles still yet to run which have a chance of beating the 5N and R1T’s times.
So, another successful year for EVs at the mountain.
Electrek’s Take
Both of these records set this year are extremely impressive. I asked Rivian if they thought they could get sub-11 minutes, but all they committed to was trying to beat their record from last year.
But the fact that a 7,000+ pound truck managed to beat even the 2018 Model 3 Performance is quite exceptional. That’s a lot of weight to push up a mountain and around all those curves. I’m sure that the new Model 3 would be quicker, and there have been faster Teslas up the hill in modified form, but these vehicles aren’t even close to being in the same class – so the R1T has achieved a pretty incredible feat here.
It’s a shame that the Ioniq 5N couldn’t have been just a tiny bit quicker to beat the Bentayga – but it also costs less than 1/3 as much as the Bentayga. The fact that you can go right out and buy an Ioniq 5N, for a pretty reasonable price, and have an SUV that beats every other electric vehicle ever to go up the mountain and almost every other SUV/crossover, with a sub-11 minute time on this famously difficult race, is extremely impressive.
Hyundai has only just started pushing the electric performance envelope, but we’re pretty excited to see where this goes.
(And speaking of Rivian, and of electric crossovers in a rally competition, can you just imagine what the Rivian R3X is going to look like up this hill in a few years?! Stay tuned!)
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Elon Musk haters have vandalized dozens of Tesla Cybertrucks being held ahead of delivery at a parking lot in Florida.
As we previously reported, Tesla has briefly halted Cybertruck deliveries due to a problem with its windshield wiper motor.
This has resulted in Tesla accumulating Cybertruck held before delivery at many locations around the US.
Over the last few days, I have been sent half a dozen videos of people dumbfounded about finding parking lots filed with Cybertrucks.
When I received this one from the OnlyinDade account, I thought this was just another one of these videos, but there was more to it:
People who seemingly dislike Elon Musk have decided to vandalize dozens of Cybertrucks sitting in a newly leased parking lot in Fort Lauderdale.
It’s unclear if the ‘f*ck Elon’ graffiti is easily removable or if there’s actual damage to the vehicles.
Electrek’s Take
Without justifying this really dumb act, because there’s no justifying it, this is an example of “Elon is Tesla, and Tesla is Elon.”
Technically, all these vehicles are Tesla’s property – though they are already meant for customers, they just haven’t changed hands yet. It makes no sense to vandalize Tesla’s property because you dislike Elon, but a lot of people see Tesla, a publicly held company, as Elon and Elon as Tesla.
That’s partly Elon’s own doing.
Again, I’m not trying to justify this. It’s obviously the wrong thing to do and ultimately, it will just radicalize his fans even more.
But it does show that Elon is becoming an increasingly polarizing individual and it is problematic to have such a divisive person as the head of such an important company as Tesla.
How about we just don’t vandalize private property. That’s a good standpoint to build on.
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