Types of Electric and Hybrid Vehicle

Ultimately, there are two ways to power a car:

Fuel, usually derived from Petroleum but sometimes agricultural sources or coal (namely Fischer-Tropsch), burned in an internal combustion engine, or Electricity, either generated in the car with an internal combustion energy or fuel cell, or stored in a battery--or both.  Since current batteries have low energy density compared with fossil fuel, all modern electric cars use various means to minimize or recapture electricity, most importantly, regenerative braking.

There are relatively few Pure Electric vehicles on the market although this is changing rapidly.  These must be charged by plugging them into a source of electricity.  The people with electrics I know seem to fall into two classes: about half have installed high power--7KW or more--chargers.  Tesla has a supercharger: 120KW, but as far as I know, nobody has installed one in their home.  The other half have not bothered.  They use ordinary 120V power to charge their cars and do not find it to be a problem.  In all cases, their daily commute is less than 15 miles.  (Most 120V chargers limit power draw to 1200W.  I suspect this is due to concern over sketchy wiring and long extension cords.)

Pure Electric cars include the Tesla (all models), and Nissan Leaf, the Smart ForTwo EV, quite a few others.  The runaway success of the Tesla has provoked nearly all the big carmakers to follow suit.   Most have range well under 100 miles, although the Tesla can go over 200.

The most common type of EV by far right now is the Parallel Hybrid.  All of these can be powered either directly by the internal combustion engine or directly by the electric motors, running off the battery.  This involves a complicated transmission.  The IC engine can power both the transmission, and a generator.  Most are have fairly limited range and top speed under electricity.  the battery and generator are usually quite small.

Nearly all of the parallel hybrid makers are making or soon will make a Plug-in version, which allows you to top up the small battery.  They generally haven't added enough battery to give much all-electric range.  There is a substantial aftermarket for larger batteries and plug-in circuitry.

Parallel Hybrids include the Prius and related Toyota products, such as the Camry, the Ford Focus Hybrid, Most of the Honda hybrids, and quite a few others.  The Chevy Volt and the new Cadillac ELR are technically Parallel Hybrids although they are mostly Series Hybrids.  I'll get into this later.

A Series Hybrid is mostly a pure electric vehicle, but it carries an on-board engine and generator.  This is much simpler and more efficient than a parallel hybrid, but for some reason, most of the carmakers didn't go that way.  I think they were concerned about the size and reliability of batteries when the first hybrids were being introduced.  The power of a series is constrained mainly by its battery: a bigger battery means you don't need as big an engine. 

The most important series hybrid on the market, the Chevy Volt, was apparently felt to not have quite enough oomph going up long hills, but instead of improving the battery, they put in a bigger engine and made a clever clutch device which engages the transmission with the engine when the electrics weren't enough.  This technically makes it a parallel, but as long as the clutch isn't engaged, it's a series.  I believe most buyers of Volts would have preferred to have less power on hills and longer electric range.  Most of my friends who own them rarely if ever drive fast or far enough to engage the engine.  The new Cadillac ELR uses the same mechanism.

GM has another variation, which they've dubbed a Mild Hybrid.  This is an entirely normal internal combustion car, with an oversized battery and starter motor, and a small amount of extra electronics.  When you stop the car, at a traffic light for example, the engine stops.  When you press on the gas pedal, the starter starts the car moving while it's restarting the engine.   I don't think any of them bother with regenerative braking or pure electric while driving at low speed, but if you spend a lot of time idling, this could be a fuel saving.  But it's mostly marketing.

A solar powered car that resembles the performance and comfort of today's cars is impossible.  Noonday equatorial sun on a clear day is about 1000W/square meter.   The total surface area available for exposure to the sun is about 7 square meters on the typical car.  Due to inefficiency, and the fact that most of the time it isn't noon on a clear day, and most of us don't live near the equator, that means we have an average of about 500 watts if the sun is up.  That's about 2/3rds of a horsepower.  even if somebody came up with magic 75% efficient solar panels (today's best are under 40% and most are about 15%), that would only bring it up to about 5hp...still not enough.   But that doesn't mean you can't use solar panels to help recharge the battery of your plug-in.