Tesla simply retains making cool issues. On the highest of the listing is its latest addition to the lineup, an all-electric semitruck. Oh, that may sound like a dumb thought—however I do not assume so. Simply think about how a lot stuff is shipped backwards and forwards throughout the nation. Clearly a practice can be extra environment friendly, however vehicles additionally play a big position. It looks as if the Tesla semi may have the ability to make two enhancements over a conventional truck. First, the electrical truck will clearly scale back emissions (relying on the power supply to cost these items). Second, with extra onboard automation it’s possible these semis might be considerably safer than their diesel counterparts.
However what if the Tesla semi additionally had photo voltaic panels? Elon Musk already has an entire firm dedicated to photo voltaic power—why not simply mix and conquer? Tesla and SolarCity are already teaming as much as make photo voltaic panels, house batteries, and electrical automobiles a unified power system. Would not slapping some photo voltaic panels on high of this truck’s floor space make the factor extra environment friendly? You may solely be taught by attempting—so I will estimate the impact of photo voltaic panels on the roof of the trailer.
How A lot Energy from the Roof?
How a lot energy and the way a lot power (these are two various things) might you get from photo voltaic panels on the trailer? First, I assume I ought to level out the distinction between energy and power. Energy is the speed that you’d get power from the solar. On the floor of the Earth, the sunshine from the solar produces about 1,000 Watts per sq. meter. By way of power, that is 1,000 Joules each second (assuming the panels are 100 % environment friendly—which they don’t seem to be).
The typical energy a photo voltaic panel produces is determined by a number of issues. Larger photo voltaic panels present larger energy (that appears apparent). But it surely additionally is determined by the effectivity and the angle at which the daylight hits the panel. The perfect panels [available today are around 20 percent efficient](https://en.wikipedia.org/wiki/Solar_panel, they usually work finest when the sunshine hits perpendicular to the panel.
Utilizing these assumptions, let’s get some values to estimate energy for a photo voltaic semi.
First, I must estimate the dimensions. I will say that the photo voltaic panel covers the whole high of a normal semi trailer. Since there are apparently totally different commonplace sizes of trailers, I’m going to say this one is 2.6 meters wides and 15 meters lengthy for a complete space of 39 sq. meters. Second, I would like each the time and common incident angle for the daylight. I’m going to make use of a time of eight hours at 60 levels from vertical. That is clearly an oversimplification of the issue, however ok for a tough estimate. Oh, additionally I’ll use the effectivity of 20 %.
From the world, daylight angle and effectivity, I can calculate the common energy:
Because the complete power is simply the product of energy and time (in seconds), I get an power of 112 x 106 Joules (112 MJ). However is that sufficient to maintain this truck trucking?
How A lot Vitality within the Tesla Semi Battery?
To ensure that the trailer photo voltaic panel to be significant, the power you get from the panels must be vital with respect to the power saved within the truck battery. Sadly, Tesla doesn’t listing the dimensions of the battery in its truck. I am simply going to should estimate it.
Here is what I do know: It has a spread of 500 miles and it is form of like a diesel truck (however perhaps extra aerodynamic). So, if I can approximate the power used as a conventional truck drives 500 miles—that ought to be about the identical because the power saved within the battery.
In keeping with Wikipedia, a truck driving at 70 mph requires an influence of 280 hp (that is 2.09 x 105 Watts). At this velocity, it could take 7.14 hours to drive 500 miles. And since I do know the ability and the time (which I can convert to seconds), I can calculate the power.
OK, that is a lot of power. Though the power from the photo voltaic panel may appear to be a big worth, it is solely 2 % of the full battery power. Oh certain, there is a good probability that I made some poor estimates in my calculation—but it surely in all probability does not matter. Even when I used to be off by an element of 5, I am nonetheless solely at 10 % of the full battery capability. Which means that it could take 80 hours, not eight, to be able to cost the entire darn battery. Sorry, Elon: This simply would not work.