Toyota Wants Your Solar Prius To Follow The Sun

Toyota solar nav patent


Toyota Sun Following Car Patent

Toyota doesn’t sell a solar-powered car, but it does offer solar panels on some versions of the Prius. If we look further down the road, though, it looks like Toyota is interested in just how much sun a moving vehicle can see, based on a new patent we found filed with the U.S. Patent & Trademark Office.

Toyota solar nav patentCalled a, “Navigation System and Method for Determining a Vehicle Route Optimized for Maximum Solar Energy Reception,” Toyota’s patent is a way to route a vehicle in such a way that the navigation system can tailor, “a driving route for maximum exposure to sunlight, so that maximum solar energy may be received during a trip.”

Toyota knows that there are a lot of reasons a road might be exposed to or protected from the sun, including, “the angle of any vehicle solar panels with respect to incident sunlight, the degree of cloud cover over the driving route, the extent of shading of the road surfaces along the driving route,” and more. The patent also has a way to recognize whether trees on the side of the road might block the sun or not, as you can see in the image to the right.

Toyota is pretty clear about what it’s thinking here, saying:

It would be beneficial to have a navigation system and method for estimating the vehicle solar energy reception along as much of a proposed travel route as possible, to enable a user driving a solar-powered vehicle to receive the greatest amount of solar energy while traveling between a start point and a given destination.

The New Toyota Prius Plug-in aka Prius Prime

The Toyota Prius Prime currently has solar panels on the roof, which can add a few miles of EV range a day. Shoichi Kaneko, the chief Prius engineer said in the past that foreseeable solar panels could increase that to six or so miles. “We are aware that the panels are supplying only a small amount of electricity. But this system is still a breakthrough as we are making use of the energy we would be wasting otherwise. By filling all available space with cells, it is possible to extend the range easily to 10 kilometers (6.2 miles),” he said last month. The Karma Revero also has solar panels on its roof, which can generate up to 1.5 miles of electric driving each day, depending on the weather. And, of course, where you let your nav take you.

Source: USPTO

Categories: Toyota

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17 Comments on "Toyota Wants Your Solar Prius To Follow The Sun"

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Can you really patent this? This would just be a route plane which would take solar raditation into account…

The sunshine route will send you 30miles out of your way so that you may gain 3 mile….l m a o…although some kids from down under claim to have an actual Solar Car …so..?? Never know..

Part the algorithm is shady roads vs sunny roads and energy gained vs. energy lost doing it.

Also interesting will be parking advice to gain most solar energy, direction and location.

So, when I drive to Oregon, at the end of the month, to get into full view of the solar eclipse, this Toyota will pull a U turn when I start getting close?

Lets hope so.

I was skeptical, until I realised that 6.2 miles per day is actually rather interesting, compared to the average miles driven.

First let’s take a look at the average miles driven per year: 13,476 *
Now let’s take a look at the average miles gained via solar per year: 6.2 * 365 = 2,263

That would mean an average of 16.8% free miles per year.

* source:

ps. I seem to recall EV Trip Planner already accounts for temperature and wind in their route planning (

I’d speculate the money spent on a solar panel integrated into a car roof would be better spent on more batteries to extend range.

I’d speculate the money people spend on granite counter tops would also have a better use. People like to buy stuff that isn’t practical and show it off to people.

Or putting wood or chrome on a car with no structural benefit but extra weight. Integrated solar cells have a very low mass, less than a pound, and if part of a solar roof, they can have no additional mass at all. A pound of extra battery will convey 0.12 KWh of storage, or only half a mile of driving.

6 miles is maximum under ideal conditions.
Who leaves their car in the sun all day?
I look for shade.
So take those numbers and divide by 5 or 10 or more.
Cells would have to have concentrators in them to offset the non-ideal real world usage.

Only usage I could see is a fan to vent the car for the poor soul who had to let their car sit in the sun all day because all of the shaded spots were taken.

Most people park their cars all day at work in parking lots that have limited at 11.

I live in the north. Last week a guy we hired that had moved from the south parked near me. I was reminded of when I lived in the south because he had one of those things that fold out and have foil or whatever on one side and you fold it out and stick it in your window to reduce heating and prevent your interior from getting washed out by sunlight.

I think an awesome product would be that very same product but have it be a flexible fold out solar panel. Then that product should have something like a cigarette lighter electrical wire attached to it coming out of the solar panel. You plug it into the cigarette lighter and it charges at let’s say 50 watts all day. I know the regular electrical stuff in a car is tied to a standard 12v battery not the main battery, but we aren’t far from having the main battery and the car’s electronics being the same voltage and removing the need for the 12 volt lead acid battery. Presumably this folding thing would be pretty cheap.

Flexible adhesive solar panels for your RV roof. It would seem you could just use these for a few hundred bucks on your car roof.

Awesome. The car will have a lot of extra solar gain heat in the cabin, but the extra energy from the panels can be used to power the air conditioner.


I wonder if the computer systems that contenders in the World Solar Challenge use to determine ideal speed (the route is fixed) count as prior art.

It is a bit different because they focus on energy use and optimization on slopes, sunshine is almost always present from Darwin to Adelaide. There are not many threes or shading buildings on the road and as you mentioned the road is fixed.

They do account for shading by clouds.

Sometimes it is advantageous to speed up when the sun isn’t shining, to get away from under that cloud.