- cross-posted to:
- technews@radiation.party
- cross-posted to:
- technews@radiation.party
Sweden is testing a semi-truck trailer covered in 100 square meters of solar panels::A Swedish manufacturer wants to harness green energy from a cargo trailer’s free real estate.
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Rough estimate of 72 cell panels at 2m² and 500W per panel puts this at a peak performance of 25kw. More than twice the average home installation.
Yes, but also much less efficient due to the angles. These panels are either completely flat or completely vertical. Ideal conditions have them facing south at an angle.
I feel like it could be great for running cooling systems on trailers and stuff like that, not sure if it would be worth the hassle for adding range.
Even on a purposely designed solar car like the lightyear one it really only works because they used all the weight saving and aero tricks possible, which you can’t really do with a truck that’s supposed to haul cargo.
Yeah. the one good use I see is reefer trailers. Since some times they have to sit long times, with still the coolers running to keep the cargo within demanded thermal limits to keep the cold chain uninterrupted.
Most cooling is obviously needed when it is hot… so in summer and thus sung light time. So the panels would probably nicely run the coolers instead of having a fuel burning generator keeping the coolers going.
During winter, when there is no light. Well it’s probably cold enough ambient the reefer isn’t using lot of cooling anyway.
20kwc capacity: nice also add 20kwh lithium storage at 200kg weight and it could help in few instances like cooling perishable cargo or driver’s cabin when engine shut off, but definitely not to expand range
Putting solar on moving vehicles makes no sense except for very specific use cases.
Install those same panels on the ground and you can point them at a good angle for sunlight capture 24/7, don’t have to literally carry the weight of them everywhere, don’t have to worry about them getting dirty all the time from moving around winter roads, and are much easier to repair.
I’m not a solarogist, but how do you capture sunlight 24/7?
Oops 🙊 you know what I mean though.
bet on moonshine
It’s Sweden, it works weird
Put solar panels on a vehical and move it around the globe xD
Put the panels on a plane that flies above the cloud and chases the sun around the earth. And then use all the captured energy to power… the plane?
Solar panels on one side, lunar panels on the other! Boom! Free electricity 24/7!
It makes more sense than solar roads.
Solar ditches make more sense. Carrying solar panes add weight and air resistance. The trailer area is 416 ft which can hold ~33 panels if panel configurations are optimized for a trailer. Weight will be 3000 lbs, which cuts the tare payload by 6%. This is not enough electricity to run a semi with two drivers splitting driving responsibilities, running day and night, and in weather that does not have power for the cells.
Trains are the most efficient system that we have. I wonder how the math would work for trains? I expect that it would be a net gain, but the added complexity of connecting and disconnecting for each car as the cars get switched in yards would be a nightmare. Once travelling, there is little braking and acceleration, which lowers the power demands.
Yes but sadly no one wants to talk about trains.
It’s really killing the Utopian dreams of public transport
Pretty sure these solar panels aren’t just your regular residential or commercial building panels. They are specially made for this purpose.
Those don’t exist.
Amount of power that can be generated is dictated by the angle to the Sun. You need to be perpendicular. Panels on the ground can slowly move and rotate to kind of track the sun. Or you put a bunch of mirrors and make a tower made of solar panels.
Solar panels on roof tend to be fixed infrastructure. You get what you get.
So if they apply panels to a vehicle you have two options. Flat or angled.
If they’re flat and the only time you’re ever going to get the maximum amount of power from them is during noon when the sun is directly above your vehicle. If angled that means the height of the vehicle has changed and they direction that they work is very dictated. If they track the Sun then they’re probably going to waste more power than they can ever produce by constantly moving because you’re on a vehicle that’s constantly moving.
Those don’t exist.
No one said it does.
Generally speaking, solar panels aren’t optimized for near-constant traveling. As such, it’s “fairly involved from a technical point of view,” said Falkgrim. Despite only recently starting prototype testing on Sweden’s public roads, he explained the project is “about seeing if the solution makes sense, and so far we believe it does.” Although such a design isn’t expected to become widespread on roadways for a few years, Scania’s initial testing shows the tech is not only feasible, but promising.
While they could do things to mitigate the angle of incidence, ultimately that same photovoltaic material will fare better angled consistently toward where the sun might be. If you’ve run out of room everywhere else, sure, time to look at trailers. But so long as we have spare other places, those are better places.
The trailer might be going through shaded areas, there’s only so much optics can do to correct for angle of incidence, and the added weight means we are using energy to move them around when they’d be better off stationary anyway.
Even residential solar is a dubious proposition, since you have to work around roof lines that are rarely optimal for solar. In that case it can make some sense for owning your own generation, particularly with battery, to go “off grid”, but I have a hard time imagining similar for the trailer.
Thing is, we’re no where close to running out of room. There’s lots of land to use. I cannot speak for every country, but the US for sure has vast areas of nothing. A truck stop with a solar array nearby storing it for when the trucks stop buy to me makes way more sense to me at least.
Depends on how much power you can efficiently harness I’d imagine
A 220 watt solar panel will somewhat efficiently charge a 12v battery on a clear day
An electric car uses about an 800v battery(s) which is about 67 normal batteries. Let’s go ahead and say a small truck would take twice that and hey to make it a round number let’s call it 2000v. That means you would need a solar panel that can produce 440,000 watts or .44 Megawatts.
Some Google fu shows that to harness an entire megawatt(1 million watts) you’d need about 5000 conventional solar panels which on the ground would take up about 5-10 acres. Pretty impractical to put half that on the back of a truck I’d say.
You’d have to have some extremely efficient solar panels to make it practical methinks. Might work on smaller cars though. Anyone feel free to jump in here and get me with an epic slam though
Yeah, it certainly seems like a challenge. I’ll be interested in seeing where they go with it.
Those don’t exist.
No one said it does.
Pretty sure these solar panels aren’t just your regular residential or commercial building panels. They are specially made for this purpose.
This you?
It’d be good for temporary power after a natural disaster or for an event.
A tractor trailer FULL of solar panels would be great!
It’ll help a little in the long summer days. In the winter, when it’s mostly dark, removing the panels to save weight may be a good idea.
So it seems they might cover a weeks travel assuming 1000km per day. I wonder how much extra weight this would add, and if it’s significant compared to the extra weight of the battery and cargo.
It’s gonna be significant.
Every extra bit of weight is one less bit of freight.
Also gonna be a lot more annoying when a shipper punches a hole in the side with a forklift.
Solar is not that efficient. They will gain a extra mile. Whoop Dee doo.
Solar is getting more efficient by the week. It’ll always be a marginal gain but it’s still a gain. An applications engineer somewhere is likely doing the cost benefit analysis to determine the cost per panel to km of drivable energy produced to determine the x number of year return on the panels. If you assume the lifespan of a commercial long haul truck is about 20 years it could add up to a decent amount of energy savings and the panels would still retain some salvage value after that lifespan.
I love your optimism, bit that’s not how any of this works.
It will never be more efficient to put panels on the vehicle. Any vehicle ever. Dirt, trees, buildings, bridges, tunnels, etc. All block light. And panels available today, are around 23% efficiency. And they only get worse over time, estimated a 90% lots at 20 years.
Could they make better panels someday, sure. Would it still make more sense to put those panels on top of buildings or an open areas where they can get lots of sun. Yes.
The issue is that while it may be a trivial gain, that same photovoltaic material would generate more energy in a fixed installation. Also, as an installation on a truck, the weight of the system contributes to the energy needed to move the truck, somewhat negating the benefit.
So sure, have your electric truck. The trickle charging of any onboard solar system wouldn’t even be noticeable though, and it’s better to have the panels on grid helping drive the charging infrastructure. I saw someone guesstimate a theoretical peak of 25kw. My car charges at home at half of that, and even for my comparatively tiny car, that takes a long time to restore range, compared to it driving down the road. The truck might be able to get an extra 5 miles of range per hour of peak sunlight with 25kw system under realistic conditions, and that same material might be able to extract 40-50% more energy over time in a fixed installation.
Might be enough to run the compressor if it’s a reefer.
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I just want to point out that 50,000k = 50,000000.
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5,000 not 50,000
Imagine testing solar panels in Sweden
Would work for roughly 4 months every year lol
Enjoy those super-long summer days and truck it South for winter. Yes, still silly but I’m just trying to make this work.
It’s free real estate.
I swear it seems like some of these harebrained schemes must be being created by people who want solar to fail so that they can point at the failure when the dumb idea doesn’t work.
I’m guessing it won’t be driving to Lapland this winter.
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It is also added cost, added weight and complexity. It is only a good idea when those factors are outweighed by the benefits it brings - which is increased range? Or would it be better to put those solar pannels in stations alongside the road where trucks can go and charge up again? Then you can better place the panels to make more effective use of the sun rather than only having maybe half of the facing the sun at a time.
There are trade offs to everything and even if it is just wasted space does not make it a viable solution. We have seen foolish tests before - like the various companies trying to put solar panels under roads which has been a utter failure every single time they have tried - expensive, less efficient, and quickly needs to be replaced due t all the ware. Vs doing the saner thing and putting them above the traffic or in car park roofs… At least this idea has more merit then that. But still worth asking the question as to if it is the best use of resources.
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With all the solar roadways test projects that have been done over the years that every time the experts say is a complete waste of time and then end up failing completely - I don’t assume that everything is taken into account any more. This seems like one of those ideas were the resources could be better spent on a different design.
Though I have not run the numbers - I am just skeptical of this solution. Not saying it wont work - just I don’t have high hopes for it to be a good solution at this point in time. It seems to me that solar panels in static places are still needed and are more efficient and can feed into the grid when not feeding a battery. And we should be questioning if this is actually a good idea. We seem to have a lot of ideas that sound good on the surface until you actually run the numbers - yet projects like that still get funding. Especially around supposably greener technology solutions.
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Their efficiency (in terms of how much solar energy is converted to electrical) is not that important I don’t think. Yeah, more efficient would be better. But ATM cost is the bigger factor. Bring that down that solar becomes more and more viable. Lower cost means we can buy more solar panels - we have lots of places to put them so energy per square foot is far less important that the energy per cost of a cell you can get.
We have a staggering amount of otherwise unused space to put them - on top of buildings, over car parks, and if we really need to over roadways. Hell, there were some interesting projects about putting them over rivers/lakes which has the added benifit of reducing evaporation and increasing the amount of water preserved under them which also goes to help places that are in need of water.
There is a lot of places we could be putting them. On moving trucks and under roads these trucks drive on just seems like the last places we should be considering. I can see a time when solar on cars is useful to extend their range without needing to plug in as much - but that is when solar is cheaper and when we already have enough static solar (and other renewables) as static infrastructure.
You should be watching the generation capacity rather than efficiency.
My roof happens to be incredibly well aligned for solar, and most months I generate more energy than I use. About 1.2 MwH per month. The fact that the panels are “only” maybe 19% efficient doesn’t really factor into my reality. The factors that matter are system output, cost, and my usage.
Efficiency helps on the power output per unit time, but better to focus on the end goal rather than the contributing factors. Depending on your location and house design, you might be good to go already, or even a hypothetical 30% efficient system would fail to get you everything you need.
Because the people who greenlight these projects are usually just idiots in charge of things. This will waste a bunch of money but will give the appearance of trying to do something. They’ll make a bunch of money, and they look good doing it. When it fails they will pass the blame to someone else.
I could see this working for either running cooling and such for refrigerated cargo or if they stick a battery in the trailer. In the latter case it would be possible to just charge it for free while the trailer sits in a lot somewhere. Then when the truck comes they plug in the battery and use the stored up power.
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