Power   and

 Electric Highway & Road Vehicles

Safe, low-cost, non-polluting future road vehicles proposed and analyzed, hoping it inspires discussion:

Consider dual-mode high-performance electric cars and trucks (EVs), powered by onboard batteries plus external/in-transit electric power supplied to them on electric highway infrastructure, from grid/solar/wind/flywheel power sources. Such EVs, capable of sustained high speed, would have unlimited range on electric highways, at far lower cost than existing travel by fuel-burning autos and trucks. 

Also consider low-cost commuter EVs, powered mainly by onboard solar power photovoltaics (PV). They include a physical fitness option that extends their power. They could transport their drivers, passengers, and cargo, at zero power cost, to most destinations, without ever needing to stop at electric charging stations, gas stations, or need for electric highway infrastructure !! 

Dual-mode EVs and Electric Highway Infrastructure for Practical, High-speed, Unlimited-range Road Travel:

You get into your EV, whose onboard batteries are fully charged from household power and onboard PV on all its top surface and windows (image at right).   

Then, on battery and solar power, you drive to an electric highway that can supply in-transit power.

Your EV accelerates to ~60 mph on battery power, and reaches the electrified EV lane. When its automatic steering acquires lane center, it extends its 2 power contacts to power strips embedded on and parallel with the roadway beneath it (image at right). Now your EV gets most or all of its power (for propulsion and battery charging) from the power strips.

Or the power strips may be installed in a center divider (image at left). Your EV would extend its 2 power contacts at its side, to make contact with the power strips. In either case, the power strips are recessed within insulation, to prevent inadvertent contact with people or animals on the freeway.

Automatic collision avoidance is another of your EV's features, that would increase safety and traffic flow.   

When your EV approaches your off-ramp, its power contacts are retracted (image at right), and it prompts you to exit the freeway. Now it's running on its onboard battery and PV power. Your EV, with its PV and home garage power, automatically maintains optimum battery charge, with no action or chore required from you  (image at right). You never buy fuel at gas stations, or stop for a battery charge. And your EV will cost far less to own and drive than today's fuel-burning car.

All elements of the technologies described here have been built, tested, and demonstrated. They all work very well, but are not commercially available. That requires cooperation from road authorities.

Left: Image of dual-mode EVs on electric freeway; which has PV solar panels mounted on center/safety divider and side/sound barriers, plus roadside PV covered shade for livestock or rest stop, and roadside windmills.  Local stationary flywheel batteries (probably underground) provide stored power, for driving after dark, and whenever wind speed may not be high enough to provide adequate power on demand.

Through relatively short underground conduit feeder lines, these solar and wind sources,  plus flywheel battery or grid power, feed electric lanes.  Power strips  need not be continuous (e.g., breaks shown in power strips above).  In this mode, EVs are powered, via their extended contacts, by the power strips. 

Ideal sources for in-transit EV power would be from solar and wind converters,  especially on routes distant from power grids.  They are rapidly becoming cost-competitive,  proven technologies,  that are being applied globally:


Above left:  PV source that doubles as rest stop shade and shelter. They could also serve as shade and shelter for pasturing cattle, sheep, etc.
Above center:  Highway sound barrier supports PV panels in Switzerland.  This solar power, in proposed system, could give EVs essentially unlimited range on freeways that supply in-transit power.
Above right:  Highway sound barrier above planted slope, with integrated PV panels,  in Austria.  An upcoming project in Holland will use PV,  installed on railway right-of-way,  to power an entire electric rail system.

Left: CyberTran has successfully completed tests in Alameda County, California.  Each vehicle is part of an electric public transportation system.  Each has first class seating for 6 passengers, can be configured to seat 20 or 30, is guided by computer control (no human driver aboard) and can travel at speeds up to 150 mph.

The vehicles' steel wheels ride on ultra-light rail.  Rolling friction is lower than conventional road vehicle tires.  At its high speeds (like above 60 mph), aerodynamic drag exceeds rolling friction.  Power is supplied to it in-transit,  via contact with power strips,  so they don't need onboard batteries.  But you can't travel in it from your home and back,  like in your EV.  Since they don't need a driver,  expense for idle vehicles is not prohibitive.  So they could accommodate more flexible schedules than today's large trains and buses.  

Future transportation, based upon shared use of  electrified highways (like that for CyberTran), by public and  privately owned electric vehicles, would be ideal.  Our roads and highways are already shared by public and private vehicles, so a shared infrastructure is not a radical departure.

Clearly, the critical missing link, to applying grid, solar, and wind power, to the proposed EV highway for privately owned vehicles, are power strips on the highway -- and these have been working well, in one form or another, as demonstrated by CyberTran (above); and with many trams, trains, and amusement rides, for over a century!

Automatic servo steering, electronic collision avoidance, and power contact deployment on the proposed dual-mode privately owned EV are straightforward technologies, that have been available and have been shown to work very well for at least the past 30 years.  

Owning and operating the proposed EVs will cost far less than today's fuel burning vehicles, especially when produced in large volume.

Environmental benefits will be profound.

Obstacles to implementing this system are not technical.  They are institutional. When we overcome that, we'll have great new road travel options, from sustainable technology for far safer travel and a cleaner environment.

Historical Perspective and Present Status:

Chemical batteries powered the first electric road vehicles over 100 years ago, introduced about the same time as fuel-burning cars, as alternatives to horse-drawn carriages. They were clean, elegant, and convenient, but had practically no infrastructure to facilitate battery charging, and range was short. Fuel-burning vehicles had greater range, and soon had ample road stops for fuel.

Rail vehicles were powered by fuel, or in-transit electric power where that was more practical and fuel emissions a problem. Amusement parks have operated rides with electric drive almost as long. 

Over the past 3 decades, Fradella developed ultra-efficient electric motor propulsion with regenerative braking, described in his US Patents 4085355 and 4520300; his flywheel power storage in 6566775 and  679477 and 8242649; his generators in 7646178 plus published patents pending. 

Fuel-burning & Hybrid Electric/Fuel Vehicles & Fuel-cells:

Hybrid autos are available, that carry a fuel-burning engine and generator onboard, along with batteries and electric propulsion. Their fuel-burning engine can be a bit more efficient and pollute less than a conventional engine, but they cost more than conventional fuel-burning autos.  US taxpayers gave more than $100 billion bailouts to auto makers, and $billions more is being given, to develop more efficient fuel-burning engines, hybrids, and fuel-cells (that don't work).  

Fuel-burning vehicles carry what too often amounts to onboard incendiary bombs (in their fuel tanks). They pollute, kill, and worse.  But transportation is a basic and critical need.  Politicians have mandated "solutions" to air pollution, fuel shortages, and a horrendous number of people killed and maimed by highway collisions. It burdens drivers, and not solved targeted problems.  For example: Despite high costs most auto owners pay to reduce their auto's emissions, they continue to pollute. Despite mandated seat belts and air bags, about  30,000 to 40,000 people are still killed yearly in the US, in auto accidents (plus millions disabled yearly by serious auto injuries).  Clearly, for the high death, injury, and financial costs paid, the mandated "solutions" are not working.  

Onboard Flywheels?  We don't think so.

Flywheel promoters have been talking, for over 20 years, about onboard flywheels they can produce, that can power cars better than lead-acid batteries, and facilitate longer range. But nothing meaningful has been demonstrated by any of them:

Several onboard flywheel battery projects have been funded.  Their promoters say they can power EVs, but performance to date and reasonable engineering studies contradict that. Their predictions, about how magnetic bearings will solve their mechanical bearing failures, serious heating, and power loss are not based on sound engineering.   Any serious analysis indicates that these projects will not result in safe or practical onboard EV power.

At this time, despite tax-funded flywheel battery and fuel-cell projects, chemical batteries remain the only viable, cost-effective onboard power storage for EVs.

Solar-powered EV Developments:

Lower-cost higher-power-to-area PV and new power electronics can enable practical EVs with onboard PV.

Left: Manta, a solar-powered EV developed and built by MIT students. 

Engineering students at various universities build EVs powered by batteries, plus solar powered EVs with minimal batteries, mainly to compete in races.  They use mostly donated parts.  

The valuable information from their work  helps to develop practical, low cost, and widely applicable EVs, that provide comprehensive solutions for current environmental and energy problems. 


Right:  One example, of a practical neighborhood EV, carrying only a few chemical batteries, PV on most surfaces that sunlight can reach, plus optional muscle power from its driver and even from a passenger.  If your health and fitness are priorities, EVs like this can help our environment, provide local transportation at a small fraction of existing fuel-burning auto cost, and won't need public charging stations.

The image below shows all main features of this unique EV, described in more detail in RPM webpage

One of its 2 motor-wheels is shown in the illustration below, with a wheel cover removed to show the 8 springs that connect the motor to the wheel rim. Unlike almost all motors, this one spins about a non-rotating wheel support shaft. The motor is shown in red. The hollow (so 4 power conductors and 4 signal conductors can be brought out for connection to onboard motor control electronics) shaft within the motor is supported by a body support structure at each shaft side. Ball bearings in the motor serve also as wheel bearings. Unique new features such as this will reduce need for maintenance, parts and weight, and increase EV reliability and efficiency.


Left image: This EV's onboard PV with power maximizer electronics to batteries, external power connections to home power outlet or (if ever available) electric highway power strips, rectifier, pedal power generator, motor controller electronics, and motors. 

Motor controller electronics is responsive to drive and brake controls on the EV steering wheel.

Its power input rectifier also would prevent sparks between power strips and EV power contacts to possible future electric highway power strips. This would prevent contact wear -- a problem seen with old trams and trolleys.


More Details about Dual-mode EVs and Infrastructure for them

In March 1976, the University of California at Berkeley's Institute for Transportation Engineering published a paper, "Electric Highway Vehicles... Technology Assessment of Future Intercity Transportation Systems" contributed by Dick Fradella. It described and analyzed a proposed EV technology and infrastructure, where EVs would carry batteries and an onboard charger, that could be supplied power in-transit, by rolling or sliding contact with electrified strips on electric highways. 

The paper was part of a broader study for US DOT and DOE. It resulted in a follow-on demonstration contract they funded, at Lawrence Berkeley Lab. They advocated inductive coupling between electric road vehicles and infrastructure embedded under highway surface.

Sliding or rolling contact advantages (compared to inductive coupling) are:

Analysis of  EV Performance with Onboard PV, Battery and Pedal-power Generator:

With electric highways that supply in-transit power, the proposed EV generally would carry only enough batteries for ample acceleration, regenerative braking, and adequate range between electrified routes. Power contact strips on electric highways can have discontinuities; where EVs would run for short distances on their onboard battery packs.  EV range would essentially be limited only by the infrastructure provided for it.

Let's consider an ultra-light commuter EV, with or without electric highways:
Gross vehicle weight with full load  =  1500 pounds
Coefficient of rolling friction  =  0.01  (15 pounds drag for 1500 pounds weight)
Aerodynamic drag coefficient  = 0.1
Frontal area subject to aero drag  =  20 square feet
Peak motor power  =  20 kilowatts  (about 26 horsepower)
Battery storage capacity  =  6 kilowatt-hours  (battery pack weight ~ 100 pounds)
EV may have 10 square meters onboard PV that generates over 1500 watts for ~ 5 hours per day.  It can supply a small battery charger and power management system, that will enable discretionary loads like air conditioning when onboard batteries are fully charged.

EV wheel thrust at 20kw is:
651 pounds at EV speeds from 0 to 15 miles per hour
325 pounds at EV speeds from 15 to 30 mph
162 pounds at EV speeds from 30 to 60 mph.

Motor efficiency at maximum speed can be over 99%. Almost all loss occurs in stator conductors. Heat transfer is by conduction, with no air flow through the motor. 

Power to overcome rolling friction (watts)  =
 (2 watts/ friction coefficient)(Total pounds car weight)(mph car speed)

Power to overcome aerodynamic drag (watts)  =
 (.005 watts/sq.ft. mph3)(drag coefficient)(sq.ft. frontal area)(mph car speed)3

Computed results, over a vehicle speed of  0 to 60 mph, are shown in the next two figures.

Left:  A graph, of power needed to overcome the sum of rolling friction and aerodynamic drag, at speeds from 0 to 60 mph, for our representative EV.

At 60 mph, rolling friction consumes about 1.5-kw; aero drag about 2.5-kw; and they total about 4-kw.

Note that onboard PV power over 1500 watts, if the only power available, would support  about 40 mph sustained cruising speed, without discharging the batteries.

Range at a cruising speed of 60 mph, from 6 kwh onboard batteries only, would be about 90 miles. During daylight hours, the onboard PV can extend it to about 180 miles. At 40 mph average speed, in sunlight, range with PV power only would be unlimited.   

Parked in the sun, its PV can provide a full battery charge in 6 kwh / 1 kw = 6 hours.

Left:  A graph, of car speed vs. time to reach it, starting from zero mph. This EV can accelerate to 60 mph in less than 10 seconds.

Onboard batteries would supply the 20-kw acceleration power. In-transit power supplied by the roadway would be limited to about 5-kw, by the onboard battery charger.

While providing unlimited range on electric lanes, external or onboard PV power would normally keep onboard batteries fully charged.  Deep discharge would be very rare. Also, fast charging would not be necessary.

Chemical batteries are capable of over 1000 charge and deep-discharge cycles.  Battery life is enhanced when they are kept fully charged. Batteries left discharged over prolonged periods exhibit premature failures, even when not cycled.  Fast charging, that results in high temperatures and gas formation, shortens battery life.  Batteries costing $1000 with service life of 10 years can be expected, in EVs operated as described here.

Motor controller power electronics rated 20 kilowatts, can provide safe acceleration, drawing short bursts of 20 kw power from onboard batteries. To accelerate this EV from standstill to 60 mph, a 20 kw discharge, over 10 seconds, uses less than 1% of the EV's 6 kwh battery capacity.  Sustained power of about 4 kw at 60 mph would normally be supplied by the electric highway and onboard PV, while maintaining full battery charge.

Speed and regenerative braking would be automatically controlled at the hand controls mounted on the EV steering wheel. Brake control would over-ride speed and cruise control. Cruise control and automatic collision avoidance would not add weight, would have negligible cost, and would increase safety. Mechanical emergency/parking brakes would be included as backup. Emergency/parking brakes could be sliding contacts engaging the 2 rear motor-wheel rims .On electric highways, dual-mode EVs could be automatically guided, needing only supervisory driver control.

In production quantities, after development and usual cost-reduction redesign, this EV would cost less than today's fuel-burning autos. EV maintenance cost would be far less than autos now available. 

And its energy costs would be far less:  If electric highways charged 20 cents per kwh (about double usual utility rates), for EVs traveling 60 mph that consume 4 kw, electric highway in-transit power for the EV would cost 1.33 cents per mile. If the EV has onboard PV and pedal power that produces 2000 watts, then its in-transit power would cost 0.6 cents/mile -- because onboard PV and pedal power cost would be zero!

A fuel-burning vehicle rated at 30 miles/gallon, with fuel costing $4.50/gallon, has fuel costs of about  15 cents per mile.  Fuel-burning vehicle maintenance cost is also high. 

EV weight, onboard batteries, power electronics, and energy costs, would be scaled; depending on if it's a commuter EV, van EV, truck EV, bus EV, etc.

More RPM webpages that describe onboard PV solar-power EV, flywheel batteries, on-site solar and wind power:


Comparison:  RPM Flywheel Battery vs. others
Building-integral solar/wind power
Flywheel power storage basic physics
Dual-mode EVs and Electric Highways
EV with onboard charger, batteries, PV, motor-wheels, pedal power
Technology: Public and Business Policy
Flywheel Facts and Fallacies
Future electric power options for buildings and road travel
UPS & Inertial Attitude Control for LEO Satellites: Orbit Dynamics
RPM Broad-speed-range Generator and Wind Power 
Bleak future of business-as-usual coal, oil, and nuclear policies

If you like the technology proposed on this page, or others, the only way we'll get it is to discuss it and question our government representatives, until it becomes a high-visibility issue.  Environmentally benign, safe EVs can be available at low cost, with attractive features, if  business-as-usual obstacles can be overcome. And the best way to start things rolling is to raise the issue at every opportunity.  Thanks for your interest and action.

If you have questions, comments or suggestions, email

Aug 2015