Do you ahve any research to back that up, or is it just something that we should accept because you said it was so?
Yes and No. There are plenty of alternative energy sources being developed that have some potential. However we must live in the present, and currently only two have any real practical use.
Those being hydropower, and geothermal power. However there are large draw backs to both. Hydro power requires massive initial investment, and is not scaleable. Meaning, whatever energy generation is present, is pretty much all you can get. Geothermal also requires a large investment, is not scaleable, and has a reducing production dynamic, and finely is limited by suitable locations.
Thus both have a limited market, and are not likely to be anything but a small fraction of the US electrical energy generation.
As for the remaining alternative energy sources, the two largest being wind and solar, neither are viable. Not that wind and solar do not work... both do in fact produce electricity from their respective sources, however they can not replace a conventional source of power. Why?
Because you can't count on them. If a thunderstorm hits, how much power is that solar panel producing? None. If the wind stops, how much is that windmill producing? None.
What happens to a town that doesn't have a consistent conventional source of power? Answer... black outs. As such, let's say a town requires 200 Megawatts of power. Let us also say that town has 200 MWs of alternative energy, like Solar panels or windmills. Now unless the town wants to black out every time a cloud goes by, or the wind stops, that town will still need a 200 MW nuclear, coal or gas power plant. Thus, the alternative energy production is pointless.
"yeah well I know that when the wind is blowing or the sun is out, I'm saving fossil fuels with my panels and wind mills"
No you are not. See, wind and sun power can die in seconds. So the reliable conventional energy power plant, must be ready at a moments notice. Remember, all three run steam generators, which requires the boilers to be at temp constantly. It can take hours for a power plant to light, get up to temp, and start generating power. You think they are going to shut down the burners when the sun comes out or the wind blows? Of course not, because if they did, and it stopped, the town would be in black out till the boilers got up to temp.
So even when sun power and wind power are at peak output, there is still enough gas, coal or nuclear, burning at the local power plants to cover if it didn't exist. The only difference is the generator at the power plant is on standby, but everything is still burning.
Solar only works in locations that are consistently sunny every day with low chance of cloud cover, like the Nevada desert. Israel is big into solar power, but of course Israel is a desert wasteland, so it makes sense.
I don't know of any location with enough consistent, dependable wind, to make wind power viable.