It is true that solar power takes a lot of space, but we do have a lot of unused surface area in our cities - house rooftops.

@abgemacht about green cars
I don't know whether you're talking about hybrid or fully electric cars, so I thought I'd link to a site about a model of electric car available from a car company called BYD:
http://www.byd.com/showroom.php?car=e6
http://www.byd.com/showroom.php?car=e6&index=6
BYD isn't the first to do this either. General Motors and a few other major car companies made commercially available electric cars in the 1990's that worked pretty well, as shown in the movie "Who Killed the Electric Car".

@KaptainKool about green cars
You said diesel is the greenest technology for cars. Do electric cars pollute more than diesel cars? Is there a kind of pollution or energy loss caused by the process of storing the electricity in the car or the electric motor mechanism?

Oh crap! I just posted a reply to the end of page 1, and then realised it's a multi-page thread.

I've just read through the other pages.

@KaptainKool, I saw your statement that "battery life is just no where close to where it should be" in hybrid cars. That would also apply to full electric car batteries, so I guess you've answered my question about kinds of pollution caused by electric cars.

@DrOct, I saw you already mentioned the "rooftop solar" idea.

Also to throw the idea out there, governments nowdays don't mind paying for privately owned infrastructure either, so the government could treat such a system as a privately owned power station and pay for people to have solar panels installed on their rooves.

I'm surprised no-one has mentioned fusion power. The even safer, even cleaner, even more efficient energy producer that in my opinion should be getting the vast majority of energy research funding.

No one mentioned it because it's something that billions of dollars have been sunk into, and we're nowhere near a workable model yet. The energy needs we have need to be met *now* - waiting 20 years for research to pan out, anther five or six to build the reactors, and the usual foot dragging by those who don't like anything nuclear and we'd be lucky to see something by 2050.

Nuclear is the way to go. Clean and safe when given the attention it deserves. What happened at Chernobyl was simply due to Soviet neglect.

@Hereward77 - Fusion energy just isn't feasible at the time being, currently it is an energy loss and hasn't been able to sustain energy production at all (that is to say where it is outputting a significant amount of energy - not even a surplus) for even a second.

It could be that there is a future in fusion (though many physicists would disagree), but it is not really a pressing present matter.

@Deschutron - you would probably find this interesting:

http://www.ieee.org/organizations/pes/public/2004/may/peshistory.html

30% of all cars used to be electric in the early 1900's, however the electric cars just couldn't travel far enough... maybe one day we will see lots on the road again, but there needs to be many progressions from an electrical standpoint.

Roof top solar is pointless in large building like skyscrapers. The volume is much larger than you can collect even if you could get 100% conversion which is against the laws of physics. Fusion may require the use of He3 to be practical, which is only found on the moon in large volumes.

Solar on house rooftops would be good to offset the power needs of air conditioning during the day. Could potentially help avoid the issues California went through a few years back with rolling power outages. But you still need the base power supply that works 24 hours a day.

@warsprite - I don't think that 100% energy conversion actually violates any of the Thermodynamic laws. It is the theoretical limit, and we can't actually build anything that achieves 100% efficiency, but it is possible in theory.

actually never mind, you can't convert 100% unless you are converting to heat.

because there is always decay in closed systems

No process is 100 percent efficient due to entropy.

Roughly 20 percent of the energy generated in a heat engine (steam generation, regardless of the heat source) is converted to work. Or less, depending on how tight the system is.

@Kaptinkool Ok I may have over stated a little but I thought there was something about 100% conversion someplace, if not the Thermodynamics Laws. At least I recall reading some place to that affect. After 45+ years of reading and studing a wide range of subjects I somrtimes get a little muddled.

I guess I did not overstate at all.

@Jack Klein - technically you are right, you can never convert 100% through the means you intend. However in reality electrical heaters operate at (essentially) 100% efficiency because the wasted energy is released in the form of heat anyways. But you are right, when it comes to water turbines the actual value is 90% efficiency. I know that sounds ridiculous but it is true.

My last sentence was implicating that water turbines are the most efficient source of power generation.