Solar Energy Kit Gives Prius 10% Better Mileage

December 09, 2005 | 19 Comments

Solatec LLC's new photovoltaic kit for the 2004-2006 Toyota Prius contains two flexible, conformal rooftop-mounted solar panels that charge the hybrid automobile's auxiliary battery through a proprietary charger/current-limiter system concealed behind interior trim panels. The self-adhesive panels are 0.6mm thick, avoiding aerodynamic drag. With Solatec panels installed on the roof, the prototype SolaPrius(R) averages 55 mpg city and 62 mpg highway -- said to be a 10 percent improvement; all-season testing is in progress. The kit costs $2,195 -- and will be available nationwide through dealer franchises. It uses the same technology as the company's aircraft grade adhesive for solar aircraft research, high-efficiency photovoltaic panels that sustain aircraft in flight. Company PR follows.

New Solar Panels for Hybrid Cars Improve MPG WELLS, NEVADA - December 7, 2005 - Solatec LLC(TM) is pleased to introduce flexible, rooftop-mounted Solar Panels for Hybrid Vehicles, starting with a kit for the 2004-2006 Toyota Prius. The $2,195 kits will be available nationwide through dealer franchises. A prototype (pictured) has been operating in the Northeast for several months under mixed driving conditions. With Solatec panels installed on the roof, the prototype SolaPrius(R) averages 55 MPG city and 62 MPG highway - an overall 10 percent improvement over the pre-installation numbers.* All-season testing is in progress. Solatec's photovoltaic kit (patents applied for) adds two flexible, conformal panels that charge the hybrid automobile's auxiliary battery through a proprietary charger/current-limiter system concealed behind interior trim panels. The self-adhesive, rooftop-mounted panels are only 0.6mm thick and cause no change in aerodynamic drag. Development of the hybrid vehicle solar panels came about as a side project of Solatec LLC's solar aircraft research, which uses the same high efficiency flexible photovoltaic panels to sustain the aircraft in flight. The same aircraft grade adhesive is used on both systems. Kits for other hybrid cars are presently in development and testing. * Individual mileage can vary significantly depending on the driver's speed and acceleration technique. Installation franchises are currently available in most areas. For more information, see http://www.solatecllc.com/. Solatec LLC is a Nevada company engaged in alternative energy research, development and manufacturing. Solatec's main areas of research currently include solar, wind power and geothermal energy. Website: http://www.solatecllc.com/

19 Comments

Karim Nasser
November 6, 2007

I went to the website, I don't see how these panels provide a 10% increase in fuel efficiency. The website clearly states they recorded a 2 MPG increase. That is more like a 3% to 4% increase for the Prius. $1500 seems to be a steep price to pay for that.

Petar Zivovic
November 5, 2006

The stats from Solatec's website actually say:
Manufacturer Rated Output Voltage: 18 Volts
Manufacturer Rated Output Current: 30 watts (2 panels)
Output Current unit is AMPERES, NOT Watts. Watts is a power rating. So really we don't know what the stats are. If the 30 watts meant to read 30 amps, then power would be 30 amps x 18 volts = 540 watts, plenty of power for the accessories and still charging the battery.

This is far more likely the case. See http://www.sunpowercorp.com/pdf/SPR-220.pdf for a set of actual panel specs (different manufacturer).

To be real, you'd have to have extra batteries installed (Like Mr. Lapp) to gather energy during the to get a worthwhile payoff. However, I can tell you as a resident in Chicago, when stuck in rush hour traffic, the panels would keep my A/C going and allow me extended use on battery in stop and go traffic.

Jim Berry
August 31, 2006

Bad news for those of you whn need help with math.

$2100 cost of the panel is the roughly the same cost of 36,000 miles on gas. Since its only a 10% increase in milage, the break even point is somewhere around 360,000 miles. I hope you plan on driving that car for the next 15 to 30 years - just to break even.

Andrey Solovyev
March 25, 2006

Florent Cozon, 14 December 2005
I you work it this way: the car is parked outside in the day time, it receives on a sunny day 200 W x 6 hours = 1.2 kWh.
What are these punny 1.2 kWh will do in the total energy balance.

IDEA!
I know exactly that some good absorbing matherials already exists. So it's possible to design Hydrogen absorbing battery for the main engine support (normal pressure). You can employ solar energy during parking time to produce Hydrogen from water in order to "charge" chemical battery. Then Hydrogen will be released after the engine starts, when excessive heat stimulates the absorbent. Probably it will be quite benefitial to run first 10 miles after daylong parking using just hydrogen. On board computer could be the judge whether to charge accu battery or to produce Hydrogen. What do you think about that? It could be the hybrid solarelectric-hydrogen-petrol car.

Chuck Conover
February 23, 2006

Only 30 watts for both panels? I was thinking of attaching 2 Shell SQ-175s (~$1600) to the top of my conventional mini van to power a DVD, cell phone and maybe some other accessories. I found this article searching the web to see if anyone else had already done it.

Corby Ferguson
February 5, 2006

I think the fast growing solar industry is great. I am glad they have already seen the need for solar panels to be made out of something other than silicon, and I feel certain that they will find something that will work just as well, if not better. Trees do it. So, More solar.

It just keeps getting better and better.

Thanks.

David Power
February 2, 2006

This is from the prius technical list.

"1 hp = ~750 watts.
Prius driving power ~= 20 hp ~= 15,000 watts.
30 watts does not equal the 1,500 watts needed for 10% of the power
needed.
This means there is not enough power while driving to achieve a 10%
savings.
The charging of a completly drained AUX battery to full charge would provide:
360 / 10,000 ~= 3.6% << 10% claimed
In reality, the AUX battery is never fully discharged.
What you are looking at is a fraud that preys upon those who don't know how to do an energy analysis. You don't get 12 hours at 30 watts. But it is enough to show the AUX battery, fully drained and then fully charged could not provide 10% of the Prius commute power."
Thanks to Bob Wilson for explaning this to me.

Dave Merrill
January 30, 2006

Richard, It's just physics. Even if you could capture every advertized watt (60?) from the panels - you'd get about enough energy to start your Prius rolling down a hill... No where near 2-3 miles.
I've got an all electric switch (aftermarket)on mine, and I drain my 3 kw battery in 2 miles.

David Porter
January 27, 2006

Wouldn't it be better to entitle the article "PV panels 'said' to give Prius 10% better mileage" I.L.O. wording it like it is a confirmed fact?
Responsible journalists (and all RE folk) need to keep from hyping untested/unproven claims until the proof is in.

Richard Molby
January 25, 2006

Can the Prius run only on batteries at slow speed (25mph) for two or three miles? If so, how much electricity does it consume?

Here in Tampa we average 5 hours of sun per day. I live three miles from work. Would it be possible to drive the Prius three miles on batteries, then park it all day, charge the batteries enough to get it back three miles to home?

Lawrence Elliott
January 7, 2006

I think all you guys are being way too kind. This thing is pure hype for the wealthy uninformed. The promoters sure have big,big cahonies to make such ludicrous claims. Should be selling them from the back of a cart like all the old snake oil salesmen.

Chilukuri Maheshwar
December 31, 2005

I am working on a project to use Solar PV panels for running Refrigeration Machinery for Refrigerated Containers for use in rural India. The rooftop area available to me is 20ft X 6ft. What is the maximum power available and what is the cost? Is it sufficient to run a 3TR air conditioner?
Regards
Maheshwar

Remy Chevalier
December 23, 2005

This is a good way to keep a fan running inside a parked car on hot sunny days... or use a lap top. Boats and RVs do this... if anything, it's good emergency power, albeit the stiff sticker price... but some folks like first adoption.

Jim Stack
December 21, 2005

It's a cute idea but a solar grid tied system at home with panels at the correct angle is the real way to get the most of any solar panels.
Also the new plugin Prius+ option from Edrive and calcars is the way to then use the power produced to get a real world 100+ mpg.
Jim

Brian Julin
December 18, 2005

60W of panels (if I read it right, could be 30W) isn't even enough to carry the whole accessory load (100W in the Prius.) I'm betting the mileage claims are overblown. It's a nice, sleek system for preserving the life of the 12V battery, but at $2k?

I'll have to see some independent test results. I guess it's a good first step -- well second if you count Lapp's Prius Classic but...

Dave Merrill
December 14, 2005

Technically, these claims are very over-rated. Just charging the little 12 volt aux battery amounts to very little. There is no way for the wattage to even get through the dc/dc converter that charges (only) this little battery from the main traction battery.

I'm afraid this is all show, but no go [pun intended].

Florent Cozon
December 14, 2005

I agree with Dave, how come let say a 1 square meter of cell, (according to what I can see from the picture of the Prius' roof)with an efficiency average of let say 20% can save up to 10% of gas.
I you work it this way: the car is parked outside in the day time, it receives on a sunny day 200 W x 6 hours = 1.2 kWh.
What are these punny 1.2 kWh will do in the total energy balance.
Now, suppose something else: if the Prius' battery is already topped up (if I am correct, the max cap is about 2 kWh), where will this extra sun energy be stored, if the car is parked?
Difficult to say that is not super hype, especially regarding the prohibitive price. Will someone explain that to me please?

Nate Bourell
December 13, 2005

The idea is that they are small but heigh effeciency. But if it increases your MPG by 10% than it wouldn't pay for itself in gas savings if gass averages $3/galon for about 427,150 miles of driving. What is exciting to me is the fact that they have the technoledgy to use solar pannels in hybrids. When I bought my hybrid cyvic I a few years ago before gas started gong up, I never thought it would pay for itself and I just bought it to be environmental, but now it is looking like it will be a great investment. Who knows, if gass prices go up high enough this system might end up being worth it too.

scott tuttle
December 12, 2005

Those are pretty small panels. I'm thinking this wouldnt help much. For $2000 you'd be better off putting a grid intertie on your house.