Thanks rabinoz for answer. And don't worry, unless they show me great ice wall by taking me there in heli, or better, take me to space to see with my own eyes that the earth is flat, i'm gonna believe in nasa and their hd feeds from iss. it's way more believable and interesting.
As for renewable energy sources - yes, thay are cost effective. Depends on type and location though.
Hydroelectric generator is great in hills with rivers, not so good in desert areas. Solar arrays work marvelously in deserts and low precipitation areas, suck near poles. Geothermal(heat pumpsin global) and Iceland is great combination due to volcanics. Geothermal and antarctic just doesnt make sense. Also hard to say whether geothermal is really "renewable" as earth has finite amount of heat stored and in fissile elements in core.
And i'm inclined to agree with magellanclavichord about free energy - when you steal solar panels, or a dam(now how would i do that??

) you have literally free energy.
Though comparing solar cells to perpetuum is funny. Perpetuum anything has higher efficiency than 100% or another definition - make energy that has not been there(and anywhere else)before. Not sun, nor solar cells get anywhere near that. About only thing i can think of that has almost 100% energy conversion efficiency is electric heating in a direct piece of wire - and that's definitely not free unless you have stolen solar cells, nor making more energy.
@NotSoSceptical - as far as i've read hydroelectricity is best of all renewable sources. Most power, quite reliable unlike wind and solar, can store energy by pumping(
https://www.cez.cz/en/power-plants-and-environment/hydraulic-power-plants/dlouhe-strane.html - reserve dam in Czech Republic - too bad you can't go fishing there

) and works for long time.
@faded mike -
https://en.wikipedia.org/wiki/Electric_battery In case wikipedia is part of NASA and is not to be believed under any circumstances - It's magic!
also cosmic bacground energy - ever heard of entropy? No?
https://en.wikipedia.org/wiki/EntropyCold fusion - i definitely want this. Though i would not do it without some big radiation shield. If it worked on cold fusion, N3O would no longer be here. Instead he would be in hospital getting treated for radiation poisoning and/or cancer. Also can't see steam turbine that would convert heat to electricity in his setup. If you are reading wiki, it has article on cold fusion too.
Don't want to believe that technocrap jumblemumble? Sure, go for it. I believe in polarized crystals radiating energy too. Just for you(wink wink).
I do wonder why you guys always come up with something that is so damn complicated just to describe simple things that already have been explained, tested and verified many many times. If it was year 1750 - i'd get it, but there have been over 250 years of research, production and attempts to come with something better then battery. Ah sorry, i came here just to see the reasons why people are arguing here in the first place - so please - don't mind me. I take back everything i wrote and i totally agree- it's polarized oscillating crystal that fuses oxygen with iron by usage of background energy to make selenium that converts escaping gamma rays and bacground microwave radiation to energy and gives it out. Yes, that's gotta be it.
Have a nice day
Edit: Addition of pumping hydrodam note and typo correction