Help me, if Electric cars are good then how about the power plants polluting to make the electricity?

Keeping the issues simple helps to make the answer clear. There is a joke about someone looking for keys under the light of a streetlamp when they were lost in the dark across the street. This is what comes from confusing the problem of light with the problem of lost keys.

The problem like your question must be addressed where it is found. The EV is not the problem. Polluting power plants are an issue. This must be addressed. But the EV is like a messenger that points out where we must look for answers. There is a type of thinking that would have us kill the messenger and say that the problem is solved...

Could I sleep next to a "running" electric car in a closed garage. Sure, because it is not using combustion for power. It is not taking up the same air I would be trying to breath. It would not be exhausting chemicals and binding oxygen with carbon. It operates cleanly.

All day long it would operate cleanly where ever it would travel. As a vehicle, the EV will operate with zero emissions and so the label of zero emissions vehicle (ZEV) is appropriate as long as we are only considering the vehicle. In a search for "something bad" some might wish to ignore this.

Your issue is with charging them. This has nothing to do with an electric motor. Which is where the EV gets its name (not the batteries.) We could wirelessly feed electricity to an EV and never use batteries that need charging. (Or even use atomic batteries that never need charging.)

Perhaps you wonder at the scale of the issues. there are almost 300 million vehicles on US roads these produce about 20 lbs of CO2 for every gallon of fuel used plus the pollution produced by refining, transportation, exploration and production... By 2015 we hope to have 1 million electric vehicles on the roads. If we could instantly replace all 300 million vehicles with electric vehicles they would use between 12 to 15% of the electricity we presently use.

Roof top PV solar, Solar thermal plants, wind, geothermal, and hydroelectric plants combined presently produce far more electricity than all the electric vehicles presently on the roads.

By definition, scale, use, and finally some common sense electric vehicles are not the significant issue. They are the light that shines on some polluting power production. Thanks for the question.

Your making several assumptions about that might not be valid. One assumption, 'at the moment Solar, wind and Hydro plants are not enough for the current need', I don't understand how you can make that assertion. I would seem very easy to set up a solar recharging system, that charges it self during the daylight hours, and then transfers the charge to the electric car at overnight. Also you qualify the statement with the words 'at the moment' and 'current'. But as demand for power increases so will systems and methods of delivering the power increase.

The reason electric cars are green is because of efficiency in producing power to run them. A coal power plant creates power more efficiently than individual fossil fuel cars creating power individually.

With the greater efficiency comes less pollution.

It takes electricity to make gasoline, too. About 6 kilowatt-hours of energy per gallon. That's about the same amount, mile for mile, that electric cars use. (See link in sources.)

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If both gasoline and electric cars use electricity, the cleaner car is going to be the one that doesn't burn smelly petroleum. By far.

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Electric cars are also far more efficient than gasoline. Less than 20% of gasoline's energy actually makes it to the road. Contrast this to electric cars, where the motor is almost 95% efficient, the battery storage system is almost 90% efficient, and the power plants are all 35% or higher efficiency. (See sources.) And then don't forget to add the refining energy above to gasoline.

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The power transmission system which sends energy to cars via wire - at 93% efficient - also beats the equivalent for gas cars - trucking gasoline to thousands of service stations. (See sources below.)

indeed. Consider also the added inefficiencies:

An electric generator, if it is good, can convert about 80% of the energy input to electricity.

The power grid, with all the lines and transformers to get it to you, is about 30% efficient.

The electric motor is about 75% efficient.

There are also losses in the car's battery when you charge it, and more losses when you draw the energy out.

Ignoring the battery losses, the efficiencies multiply, like this:

Eout = Ein x (0.8 x 0.3 x 0.75) = Ein x 0.18

I suspect that with the charging and discharging losses it will be less than 0.1.

Assuming that number for the moment, to get 10 hp at the wheels of your electric car will require 100 hp at the power generating plant.

The best 'green' option is nuclear. Wind and solar are much too expensive, and not reliable enough.

It is more efficient the way the energy is produced by a power plant, but yes it is not perfect.

actually hydro dams do alooot