Sure lasers don't have recoil, but I see no reason a laser gun can't have recoil.
Anything from flywheel energy storage, a lasing medium compressed by pistons, massive magnetic fields created by high currents, who knows what's inside that thing.
A handheld laser gun has to generate a beam of such unrealistic intensity that I'd be surprised if the power stage didn't buck in some manner.
I don't see how people like you miss the entire concept of "base load".
I live in a region with vast amounts of renewable energy resources. It's always windy and the sun shines almost every day. I have solar panels on my house that cover most of my DHW and a large fraction of my summer cooling load, and keep most of my appliances running.
But right now, the sun is down and the wind is flat. And I still need power. My battery storage would be depleted by morning, damaging it through overdischarge if I don't buy power from the grid instead.
And it's a lovely summer evening with no heating or cooling demand! What about midwinter, -35C and dark and snowy? Where is my power coming from on that day, after a month of days just like it?
Nuclear.