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Funkworks

Funkworks

Low Earth Orbit, obstructing Earth's view of Venus
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Satellites, calculators, farms, and various ways to convert photon energy to electron energy.

But here's what triggered this thread: the Aptera car I like because of its extreme efficiency and aerodymics seems like it will also have the first automotive grade solar panels that are flexible in 2 axes. So that's new. You haven't seen a flexible solar panel before (say so if you have!), and I think it opens up many possibilies, not just with cars.



☀️😎🌞
 
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hobie1dog said:
"Flexible panels tend to be of lower efficiency than standard solar panels in full sunlight. They are able to convert 7% to 15% of the sun's energy compared to the 20% to 23% efficiency of standard panels."
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Sounds about right. There's always a trade-off. But if they allow for less drag, then they don't need the extra efficiency. In other words, less drag makes up for the lower efficiency. Depending on speed and so on. If they can provide enough energy for a car to run 20 miles a day, that's enough for many commutes.
 
Funkworks said:
Sounds about right. There's always a trade-off. But if they allow for less drag, then they don't need the extra efficiency. In other words, less drag makes up for the lower efficiency. Depending on speed and so on. If they can provide enough energy for a car to run 20 miles a day, that's enough for many commutes.
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Lets do some math. Solar irradiance on the ground normal to the sun is ~900 W/m2. So figure about 700W/m2 for a vehicle because the panels will not be normal to the sun. At 15% efficiency (best case above) that is 105W/m2. That 700W/m2 is only from 10 to 2 so lets say we get a good 6 hours at that 700,

700*0.15*6 = 630 Wh/m2 that may be harvested on a sunny day.
The average EV gets 346wh per mile. A 20 mile range needs 6.92kwh.
So that EV would need about 10 m2 of solar panels to get that 20 mi range.
 
jderimig said:
Lets do some math. Solar irradiance on the ground normal to the sun is ~900 W/m2. So figure about 700W/m2 for a vehicle because the panels will not be normal to the sun. At 15% efficiency (best case above) that is 105W/m2. That 700W/m2 is only from 10 to 2 so lets say we get a good 6 hours at that 700,

700*0.15*6 = 630 Wh/m2 that may be harvested on a sunny day.
The average EV gets 346wh per mile. A 20 mile range needs 6.92kwh.
So that EV would need about 10 m2 of solar panels to get that 20 mi range.
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Damn math. 😉
 
hobie1dog said:
or 107 sq.ft. , the roof of a Suburban would only get you 40 sq.ft. (4x10ft)
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On the other hand, my "commute" is often three, and sometimes seven, miles. So getting ten "free" miles every day would matter. Similarly, my pickup truck gets about 14 mpg on a good day. Ten free miles is, more or less, one gallon of gas... every day. So, at four bucks per gallon, more or less, over the course of a year, five days per week (conservatively), fifty two weeks per year, is a bit over $1000 in savings per year. Even if it was half of that, I wouldn't turn down an annual check for $500.
 
I don't care what the efficiency is. If it's 300watts, it's 300 watts.

A flex panel can be stored in an RV easier, to avoid theft or hail damage. That's an efficiency in it's own. Or campers are solar powered now. Want to run lights and charge phones at night? No worries. Can leave the fridge running all week without plugging in.

Also, can a flexible version be tossed flat on the ground and be more durable? RV stands are a pita. It's nice when I can just yeet the panel somewhere, at a campsite that isn't crowded.

Semi rigid is handy as well. Multiple glass cells, in a roll up mat.
 
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GM Energy is partnering with SunPower to develop their "Ultium Home and Commercial power solutions", a home (and commercial) energy storage system to go along their upcoming Silverado.

jderimig said:
Lets do some math...
Click to expand...
That's where the importance of aerodymics come in, and it explains the look of the Aptera. I just read last weekend (forgot where, might find it again) that on upcoming Hyundai Ioniq 6, small cameras instead of regular rear view mirrors can add about 1 mile of range. Every bit counts. The less drag a car has, the more solar panels will make a difference. If Aptera succeeds as a business, I would expect more cars to include solar panels as an option over the next decade.
 
Funkworks said:
GM Energy is partnering with SunPower to develop their "Ultium Home and Commercial power solutions", a home (and commercial) energy storage system to go along their upcoming Silverado.


That's where the importance of aerodymics come in, and it explains the look of the Aptera. I just read last weekend (forgot where, might find it again) that on upcoming Hyundai Ioniq 6, small cameras instead of regular rear view mirrors can add about 1 mile of range. Every bit counts. The less drag a car has, the more solar panels will make a difference. If Aptera succeeds as a business, I would expect more cars to include solar panels as an option over the next decade.
Click to expand...
I am an avowed solar panel and electric car booster. I would give a car with cameras instead of mirrors an awfully hairy eyeball. Especially to get a mile of range. You can pick up 10x that by just being a little easier on the accelerator off the line. If they were getting me 25-50 miles I might think about it.

I've also more or less done the math that @jderimig did above. For regular car travel, solar panels are way better on your rooftop than on your car. It's really hard to get a meaningful difference in range as noted above. I recognize that this calculation is different for renters and for people going far away from an electrical outlet.
 
boatgeek said:
I am an avowed solar panel and electric car booster. I would give a car with cameras instead of mirrors an awfully hairy eyeball. Especially to get a mile of range. You can pick up 10x that by just being a little easier on the accelerator off the line. If they were getting me 25-50 miles I might think about it.

I've also more or less done the math that @jderimig did above. For regular car travel, solar panels are way better on your rooftop than on your car. It's really hard to get a meaningful difference in range as noted above. I recognize that this calculation is different for renters and for people going far away from an electrical outlet.
Click to expand...
What I find interesting is coming up with many different ways to increase efficiency, and using them all in the same machine to get a big gain, so:

- A panel that allows both energy generation and better aerodynamics? That's amazing.
- A rear view camera that is smaller than a mirror, directs the image closer to your line of sight (a screen), has better aerodynamics, and that can be installed "anywhere" to cover a greater field of view? Also amazing.
- Efficient driving habits that are also safe and economical? Again amazing.

Combining all of the above together? Even more amazing. I love it when people come up with extreme ways to make new things happen and beat records (like efficiency). I'd take cameras over mirrors any day, but it's not legal everywhere. Not just for the small extra range, but also for the reasons above. I do think cameras can be safer.

Incidentally, I'll like to have a rear view camera on my bicycle. Facing straight behind from the seat with a display on the handle bars, that would be so great. And solar panels to charge an eBike. And an eBike.
 
I don't know much about solar panels but I've been seeing a lot of RV and Vanlife people using them to get 100W or 200W of power. And my sister has a lot of them on the roof of her house so she sells back energy to the grid during the summer. There is a lot of discussion about whether the grid can handle the load of more electric cars, I wonder if the solution is to have more home solar farms.
What I don't know about solar panels is how they are constructed. Some people don't think we have enough resources to build batteries for cars, is there a problem with the resources needed to build solar panels? They don't seem to be overly expensive for 100W or 200W versions.
Solar won't work at my house- our house is covered by large trees. We could build a framework way out in the corner of the yard to get away from the trees, that might be possible.
 
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We basically lease solar panels from our electric cooperative. We just increased the number of panels to cover 100% of our typical monthly electricity usage. We pay our normal electric rate PLUS a lease cost for the panels. Costs us more to do this than if we didn't lease the panels, but we want to encourage the electric cooperative to use more solar power. On the plus side we don't have to buy the panels or maintain them. The cooperative owns them and they are located on their solar farm wherever that is. We'll never make money off them, but given the payback period on that kind of stuff we are OK with that.
 
bjphoenix said:
... There is a lot of discussion about whether the grid can handle the load of more electric cars, I wonder if the solution is to have more home solar farms.
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I don't buy into that discussion. The US pop grew by 100M in the last forty years and no one ever worried about the grid (did anyone?). A set of running home appliances consumes more than an EV, EVs can be charged off peak hours (they all have schedulers/timers to do so), and the grid can be updated at the same rate as more EVs come along if needed.

bjphoenix said:
Some people don't think we have enough resources to build batteries for cars, is there a problem with the resources needed to build solar panels? They don't seem to be overly expensive for 100W or 200W versions.
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We ("humans of the world" or anyone) are far from reaching the limit of how many solar panels and batteries we can produce. Whether we can build enough for this or that is not a concern to me. I'd just rather see people building and using as many as possible. I also like to see their cost go down, and the panels last for many decades as being increasingly efficient.

bjphoenix said:
Solar won't work at my house- our house is covered by large trees. We could build a framework way out in the corner of the yard to get away from the trees, that might be possible.
Click to expand...
It's not easy for everyone, but it seems to me that anyone who can, should, if only because they're so cool, and more disaster proof than other power sources.

Zeus-cat said:
We basically lease solar panels from our electric cooperative. We just increased the number of panels to cover 100% of our typical monthly electricity usage. We pay our normal electric rate PLUS a lease cost for the panels. Costs us more to do this than if we didn't lease the panels, but we want to encourage the electric cooperative to use more solar power. On the plus side we don't have to buy the panels or maintain them. The cooperative owns them and they are located on their solar farm wherever that is. We'll never make money off them, but given the payback period on that kind of stuff we are OK with that.
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I guess the owners are the ones making a profit, and the leasers are getting a good service. Sounds like a good arrangement.
 
Funkworks said:
It's not easy for everyone, but it seems to me that anyone who can, should, if only because they're so cool, and more disaster proof than other power sources.
Click to expand...
I see some people with panels on their roof. That would not work at my house but thinking about it there is one extreme corner of my yard where I could put panels and they would get sun most of the day. I suppose late in the afternoon panels on the roof wouldn't work well either. My wife and I don't have a history of living in a house for a long time so I'm not interesting in a big investment right now.
 
Funkworks said:
I don't buy into that discussion. The US pop grew by 100M in the last forty years and no one ever worried about the grid (did anyone?). A set of running home appliances consumes more than an EV, EVs can be charged off peak hours (they all have schedulers/timers to do so), and the grid can be updated at the same rate as more EVs come along if needed.
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When EV's become a significant part of the US fleet (30-50%) when will off peak hours be?
 
bjphoenix said:
... My wife and I don't have a history of living in a house for a long time so I'm not interesting in a big investment right now.
Click to expand...
I think that's the main hurdle for many. The longer someone knows they'll keep a building, the more solar panels makes sense.

jderimig said:
When EV's become a significant part of the US fleet (30-50%) when will off peak hours be?
Click to expand...
Ideally, there wouldn't be any peak. We can imagine all EVs charging at different times throughout the night to make a flat consumption curve. Personally, I wouldn't care if it charges from 10 to 1, or from midnight to 6.

Maybe if there are many EVs on the same grid, the grid can select which cars to charge to ensure a flat curve. I think that's how Gogoro's private scooter charging network works. But they own everything on their network so they have full control. I'm not sure how difficult it would be to scale this to public grids. But technically or physically, it seems possible. Interesting problem, but there's plenty of time to think about it while Li mining, recycling, refining, battery making and EV adoption ramps up.
 
Here’s someone who’s been creative with flexible solar panels.



A hobby I might pick up when I retire.
 
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Funkworks said:
You haven't seen a flexible solar panel before (say so if you have!)
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Okay, so I'm around 20 days late to the thread. :) On YouTube I follow several narrowboaters on the UK canal system.
Quite a few use solar panels and a growing number are using a thin sheet type of panel which is flexible enough to be placed right on the boat's curved roof.
Someone recently, I'm pretty sure of that, mentioned one kind which can even be walked on, occasionally.
The different types of solar panels are frequently discussed in detail on videos and it is said even moreso within the community itself.

Here are examples from 3, 4, and 6, years ago,



and



and

 
Efficiency in PV is not that important. If PV's were 100% efficient then the temperature of the panel supports underneath would plunge to absolute zero and destroy themselves.
 

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