One of the first mainstream production vehicles with a solar roof panel will be the next generation Toyota Prius due out next Spring. Nissan, VW and numerous other carmakers will offer solar panels on their electric and plug-in hybrid vehicles also. One solar roof panel will only provide a small percentage of the power that todays electric vehicles require. At 20% efficiency (Suniva and Day4 Energy), a solar roof panel could generate up to 270 watts. The panel will be optional and cost under $900. Keep in mind, the cost of solar panels will gradually come down, and the efficiency will gradually go up. Already, there are cheaper and more efficient solar panels being announced. The SunFlake panel, invented by Martin Aagesen who is a PhD from the Nano-Science Center and the Niels Bohr Institute at University of Copenhagen, gets 30% efficiency and will be cheaper than current panels. Innovalight claims they have a solar panel that is 44% efficient at one tenth the cost. At the rate that solar technology is advancing, solar roof panels on vehicles will soon be over 500 watts. The next technology, coming 5 to 10 years from now, is infrared solar and solar paint, that will collect radiant heat from the entire vehicle body, 24 hours a day. This too has the potential to double the wattage again, but from twice the surface area. So we will be up to 2000 watts under ideal conditions (less depending on the angle of the sun and weather conditions).

Recently, Toyota described the 1/X Concept vehicle, a plug-in hybrid about the size of a Prius, but ONE THIRD the weight, only 926 lbs. With a vehicle that is one third the weight, the mileage doubles from the same wattage. Quantum Sphere announced a breakthrough in their lithium ion batteries that produces FOUR TIMES the capacity from the same size cell. Another breakthrough is an electric motor that uses HALF the amount of energy to perform the same amount of work. With this new electric motor, the mileage doubles again. Search: Thor Power: Revolutionary Electric Motor Design Cuts Energy Use in Half. And with that 2000 watts of solar power, we will not be powering the vehicle motor. We will be powering a generator to pulse charge a pack of individual batteries in rapid succession with a pulse width modulator, many times per second. Such a battery charger is being patented. However, researchers are baffled as to how one battery running a generator can charge a half a dozen other batteries, but they see it happening. One explanation by scientist Tom Bearden is that when a battery is pulse charged, it continues to charge for a split second, even after the current is briefly switched off. Then, with the power still off, a second line of current flows out of the battery briefly, if there is a load on it. The next pulse charge should be timed to first allow these second and third responses.

A large percentage of the coming electric and plug in hybrid vehicles will be charged at night when the rates are low, then driven to work and parked all day. If you live in a sunny location, the big pay-off will be Vehicle to Grid (V2G). This concept was originally conceived to transfer a portion of cheap off peak power from your batteries into the daytime peak load grid. You would drive to work, park your car at a V2G receptacle, plug in and tell your car how much power to sell to the grid. Then when you got off work, you would have enough juice left to get home. This was before V2G engineers realized that future vehicles would also be equipped with solar panels. Now, with lighter vehicles coming and high capacity batteries and ultracapacitors, in a sunny climate, and 2000 additional watts of power to feed into the grid at peak load rates, you would get a lot of credits on your electric bill. All of this will eventually become a standard feature financed into the vehicle, and it will pay for itself. As a last resort, if you ever needed to charge your vehicle away from home, or on a rainy day, you would plug into the V2G system and charge your batteries. The power will go both ways. Feed electric power into the grid for a credit, or draw power out as a debit on your electric bill.

Solar panels, solar glass and solar bodies on vehicles using V2G will soon power your vehicle and the local grid. Visualize whole parking lots of solar equipped electric vehicles and plug-in hybrids, capable of feeding the grid, charging, or generating power on the fly. The vehicles of the future will be portable power plants, and their owners will be managers of energy.

1) Marginal cost for energy produced is worthwhile. Cost of energy to make wheels of a vehicle move is extremely high; 25 cents per kW-hr or more, so even high priced PV panels are reasonable for this application.

2) There is very little energy that can be practically harvested on a vehicle’s surface area. Assuming even 20% efficiency, you have maybe 2-4 square meters or 400 or 800 watts on a sunny day. Assuming 4 really sunny hours, that might get you 10 miles. That might be OK, if you don’t drive much each day.

3) Panels are best built into the car, so there are no aerodynamic losses, and they won’t get stolen. This is hard to do, as it involves integrating with the vehicle design process. (Makes replacement/repair tough as well.)

With solar technology you finally have a way to put energy back into a mobile system without being tethered to a cord.

Let’s look at just some of the extra functionality that can be realized (some of these functions cannot be done with existing ICE technology because there is not enough remote power available):

1) Interior cooling. Do you like going to your car in the middle of summer after shopping? Now you can call up your car and have it starting cooling before you get there, should it be hot and sunny out.

2) Advanced remote security. You car is sitting at an airport parking lot or other remote location and you can have advanced security functions that require more energy that could be sacrificed if there was no way to put energy back into the system.

3) Topping off the battery. How about long stays at the airport? Wouldn’t it be nice that when you come back you have a fully charged battery (it was almost depleted driving to the airport) and all the advanced security functions were active? Nice indeed.

4) Systems monitoring. Advanced batteries require constant monitoring and that requires energy. Do you want to slowly drain your batteries or not even worry about it? The system will manage it’s own resources and have excess energy coming in to work with.

5) Always on Internet. This can be powered by the sun and make possible many of the above listed functions. Your computers and game machines have it at home, so can your EV.

Thus, I think the author has not completely thought though the mobile solar market and the new functionality that can be realized. The cost will be high at first but it will only get cheaper and more powerful every year. Eventually, the entire surface of an EV may be covered with solar active paint and windows. There is quite a bit of surface area on car. Additionally, there is no need to have expensive inverters to use the power. it just needs to be conditioned to the right voltage and sent to the batteries. It’s almost a perfect solution. I’m sure that once people see completely functioning EVs with SOTS (Solar on the Surface) they will be unwilling to do without it.