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JRP3
Hyperactive Member
The second post is certainly FUD but are you saying the claim that 8 tows out of 36 semis is untrue?
Not that concerning, really. First, we have no idea if that number is accurate. And even if it is, the Pepsi/Lays trucks are essentially a pilot program. There will be some bugs to work out. I'll be concerned when Pepsi/Lays expresses concern over the performance of the trucks.
JRP3
Hyperactive Member
"Concerning" was an Elon reference, he often replies to ridiculous conspiracies on Twitter with "Concerning". Too subtle I guess. However if there are 8 tows out of 36 vehicles that is a bit concerning and certainly not a good look for Tesla and the Semi program.
JRP3
Hyperactive Member
Fair enough. Do we have an accurate count of Semi tows? I've seen pics of 3 distinct trucks, a white, blue, and orange.
I am glad that Pepsi is working this out for me. Then another 2k beta testers before the factory goes live.
petit_bateau
Active Member
Thanks both. Utility solar has not really been my thing over the years, just dabbled.
The real question is not "how small a perimeter can I draw around a group of panels". Instead it is "for a random patch of land that I own, how many panels & associated stuff can I fit in".
When doing that calc - in general - that includes the unused bit in the middle or anywhere else that is too rough; includes the perimeter fence, and the outside-the-fence mown security strip; includes setback from the fringing trees; and the fringing trees that have to be maintained for visual amenity reasons; includes the inverter shacks; includes the access and maintenance roads; the electrical feeds in/out and the sterile zones under them; etc.
I'm not really too fussed what the actual number is, but we ought not to kid ourselves about the number by cherry picking only the good bits. Of course that number will also depend on latitude, and land slope and orientation. It might be as low as 100kW/acre or as high as 200kW/acre. But it would seem to be there or thereabouts.
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Similarly in the 300 kWh/day number I did per truck that was my guesstimate of an average truck (so not fully weighted up) on an average round (so not a 500-miler) on an average day (so not raining/snow/mud) on flattish ground on good condition roads. So maybe if everything is maxed out then it might be 100kWh/day or even more if they have two drivers etc.
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So we might reasonably get anywhere from as low as 1 acre of solar per truck to as much as (say) 3 or more acres of solar per truck. But it'll be somewhere in that territory.
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Gosh, are all those breakdowns real, or is this FUD being sprayed ?
Does your company have dedicated land for solar panels? Is it adjacent to your main facility?
I’m having difficulty following your numbers.
One truck needs 300kWh a day.
One acre of solar panels generates 1MWh a day (assuming 150kW*6 hours/day).
So one acre can cover 3 trucks.
Regardless, a fleet of 50 trucks would need 20 acres which is the entire area of my company’s terminal.
I would believe this if they could cite the reason for these failures. Did the trucks run out of battery? Did they fail to start? Did they fail during a run?
I don’t believe the claim that the Semis weren’t able to pull a trailer loaded with only chips. A trailer full of bags of chips is as heavy as a trailer by itself. An empty trailer weighs about 10,000 pounds, and I think even a Cybertruck can tow that much.
petit_bateau
Active Member
No problem, you've got this underlined bit wrong.
Go back to my post #2553 Tesla Semi
The global annual average capacity factor for solar is about 14%. That's simply a fact, believe me, for the global average.
So if you have (say) 1 acre with (say) 100kW of panels on it then in one day that will produce approx 100 kW x 24 h x 14% = 336 kWh.
The 14% capacity factor takes into account day/night time, sun pathways, cloud, rain, everything.
So on that basis if an average truck is using 300 kWh/day then it will need about one acre of solar if ground-mounted arrays are the fill density.
So most depots (terminals) will not currently have enough land or roofs to supply their needs. They will need to import electricity (expensive), or relocate (possibly cheaper) if they wish to self-generate.
(It may be that good land can go more like 200 kW/acre, ehich would ease things. But equally a heavily used truck might be more like 900 kWh/day which would make it more difficult.)
A lot of the 20+ truck outfits will probably be looking at solar to supplement their grid power usage rather than replace or offset it entirely. If they can defray the bill by 50% after the installation has paid for itself, that would be significant.
SageBrush
REJECT Fascism
I found some confirmation that you are right (noted below.) I'm not sure *why* you are correct, but that is my problem.
Profiling the top five largest solar power plants in the world
Solar power is enhancing its reputation as one of the fastest-growing renewable sources, with a number of the largest plants coming online in recent years
www.nsenergybusiness.com
One *possible* confounder here would be the panel angle. The photo looks pretty steep but I'm really not sure.
50 acre available for this but we only think we need 10, 2 acres of roof as well
SalisburySam
Active Member
8 tows out of ??? tractorMiles or tractorHours is not concerning, especially if they were the first 8 each towed once each due to the bus bar (or any other singular) issue.
Repeat failures are worse
Failures on later builds are worse
Different failure modes are worse
No useful data given.
petit_bateau
Active Member
Thank you.I found some confirmation that you are right (noted below.) I'm not sure *why* you are correct, but that is my problem.
Details the 5 largest PV farms in the world. I looked for them because I figured they would maximize land use, and could be considered best case examples. The two farms with both STC and area values are a bit over 6 acres per MW.Profiling the top five largest solar power plants in the world
Solar power is enhancing its reputation as one of the fastest-growing renewable sources, with a number of the largest plants coming online in recent years
One *possible* confounder here would be the panel angle. The photo looks pretty steep but I'm really not sure.
(There is a reason why I am often the unwelcome guest at the wedding)
The larger the site the better the land utilisation (e.g. one security checkpoint, etc). And as a result the better land utilisation % the better the % capacity factor, for the larger land package.
My 14% global average capacity factor is taken from IEA data. I'm not a great beleiver in IEA data (I calculate it myself each year from th IEA data re TWh output / GW input), but this number is plausible and is better than my lower bound of 10%.
Doggydogworld
Active Member
I used to have an old Solar City slide deck that claimed a bit over 1300 kWh annual production per installed kW. That's 15% capacity factor. The EIA says total US PV generation was 201 TWh in 2022. SIEA says the US installed PV grew from 122 to 142 GW during 2022. Using 132 GW as the average installed capacity I get 1520 hours of rated production or 17.4% capacity factor. Since that includes the lower-yielding residential installations, it follows that large installations average better than 17.4%.
It varies a lot with location, of course, and whether you have tracking (the majority of utility scale installations do these days). You can get close to 30% in the US southwest.
JRP3
Hyperactive Member
I guess you're being more charitable than I am. If 1/4 of the fleet needs a tow in the first 3 months of deployment that seems problematic to me, assuming the figures are correct. The latest seems to be a recent event so I'd think the bus bar issue would have already been fixed.
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