Calculations of solar production on the roof of trailer pulled by a Tesla Semi
I'm sure this has been discussed in detail already, but due to lack of search functionality, I can't find threads on it, so here are my calculations. I'm sure everyone has thought about solar on a trailer producing energy while cruising down a highway and are wondering how beneficial it would be:
Let's use a 53ft typical trailer being pulled by the Tesla Semi:
Surface area on 53ft trailer roof:
41.81sq meters
Average annual solar potential (southwest US, source N.R.E.L.):
6kWh/sq meter per day
Efficiency of solar PV on the roof (23% currently possible)
6kWh x 23% = 1.38kWh/sq meter per day
Total average daily energy generation:
41.81sq meters x 1.38kWh/sq meter = 57.7kWh/day
Possible energy losses from shading, reflection, transmission to battery etc. (5%)
57.7 x 95% = 54.8kWh/day net energy generation
54.8kWh/day x 365 days = 20,000kWh/year or 20mWh/year
Fuel economy of an electric semi pulling a trailer:
0.6miles/kWh (based on efficiency of an electric motor over a diesel engine)
Free, "Solar powered" miles by a Tesla Semi pulling a 53ft solar PV equipped trailer:
0.6miles/kWh x 54.8kWh = 32.9 miles/day
32.9 miles/day x 365 days = 12,001 miles/year
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Here are the same calculations for a a Triple Turnpike (3 53ft trailers).
Surface area is 125.4 sq meters = 164kWh/day energy generation, 59,860kWh/year
Assuming a fuel economy of 0.4 miles/kWh: free, "solar powered" miles by a Tesla Semi pulling a solar equipped triple turnpike:
65 miles/day or 23,944 miles/year
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My fuel economy numbers are estimates, they could be more or less, but what is important to note is that solar on these trailer roofs will generate 57.7kWh/day (53ft trailer) and 164kWh/day (triple turnpike) of energy. In my opinion, solar on a trailer would be quite beneficial both in efficiency and cost savings.
A 53ft trailer can fit a 13.4kWh/solar array. Assuming the cost of $1.50/watt solar hardware and installation cost = $20,000 capital investment. The energy produced per year would offer savings of $3,600/year (based on $0.18/kWh grid price, California), offering payback in about 5.5 years.
I believe all these numbers are fairly conservative and should only get better with the cost of electricity going up, solar panel hardware going down, PV efficiency improving beyond 23% etc.
oh yeah: Weight of solar panels on a 53ft trailer? 10-20kg/sq meter = 418kg to 836kg (921lbs to 1,842lbs). Nothing to worry about there.
It'll be exciting to see what specs we get from Tesla this evening.
Let's use a 53ft typical trailer being pulled by the Tesla Semi:
Surface area on 53ft trailer roof:
41.81sq meters
Average annual solar potential (southwest US, source N.R.E.L.):
6kWh/sq meter per day
Efficiency of solar PV on the roof (23% currently possible)
6kWh x 23% = 1.38kWh/sq meter per day
Total average daily energy generation:
41.81sq meters x 1.38kWh/sq meter = 57.7kWh/day
Possible energy losses from shading, reflection, transmission to battery etc. (5%)
57.7 x 95% = 54.8kWh/day net energy generation
54.8kWh/day x 365 days = 20,000kWh/year or 20mWh/year
Fuel economy of an electric semi pulling a trailer:
0.6miles/kWh (based on efficiency of an electric motor over a diesel engine)
Free, "Solar powered" miles by a Tesla Semi pulling a 53ft solar PV equipped trailer:
0.6miles/kWh x 54.8kWh = 32.9 miles/day
32.9 miles/day x 365 days = 12,001 miles/year
-------------
Here are the same calculations for a a Triple Turnpike (3 53ft trailers).
Surface area is 125.4 sq meters = 164kWh/day energy generation, 59,860kWh/year
Assuming a fuel economy of 0.4 miles/kWh: free, "solar powered" miles by a Tesla Semi pulling a solar equipped triple turnpike:
65 miles/day or 23,944 miles/year
--------------
My fuel economy numbers are estimates, they could be more or less, but what is important to note is that solar on these trailer roofs will generate 57.7kWh/day (53ft trailer) and 164kWh/day (triple turnpike) of energy. In my opinion, solar on a trailer would be quite beneficial both in efficiency and cost savings.
A 53ft trailer can fit a 13.4kWh/solar array. Assuming the cost of $1.50/watt solar hardware and installation cost = $20,000 capital investment. The energy produced per year would offer savings of $3,600/year (based on $0.18/kWh grid price, California), offering payback in about 5.5 years.
I believe all these numbers are fairly conservative and should only get better with the cost of electricity going up, solar panel hardware going down, PV efficiency improving beyond 23% etc.
oh yeah: Weight of solar panels on a 53ft trailer? 10-20kg/sq meter = 418kg to 836kg (921lbs to 1,842lbs). Nothing to worry about there.
It'll be exciting to see what specs we get from Tesla this evening.
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Comments
With a flat surface on top of a truck, there is only going to be about an hour at noon when it's directly overhead giving you that maximum yield, and it drops off pretty fast. It basically works like vector geometry, where if it's coming in at a 45% angle, it's only half the yield downward toward the panel, yielding half as much energy. Most of the day is obviously at angles like that, so it's less than 23% yield most of the time.