I never said that anything runs solely on solar, so please don't invent both sides of the conversation, or I'll just drop out and let you converse with yourself and create a fantasy of my replies. I explicitly stated that there are many backup methods for renewables, which you ignored.Then put a loved one on a respirator run solely on solar. You will learn what is "reliability".
But lets go with your definition. Solar panels get dirty or covered in snow and then do not produce the expected output.
So, if you do not know how much electricity you will get on a particular day, how reliable is that system?
The same with wind. Nobody knows how long the wind will last and how much electricity will be generated. That is a lack of reliability.
You cannot rely on wind/solar to deliver X electricity. It is a crapshoot each day based on factors out of your control.
That is why they are unreliable.
And I'll say again, you don't know what the word reliability means.
Over time, the energy output is observed and proven in the field, and known and expected, vs the calculated output. And that is all factored in.
Solar panels are typically mounted at enough of an angle in climates with snow, that the snow will slide off. If that wasn't done, it's not a fault of the technology, it's a fault of the the installer. Just as a natural gas or coal powered turbine seizing because the blades were not machined and installed correctly, is not a flaw of the technology itself.
You cannot rely on wind/solar to deliver X electricity.
And yet, that's exactly what utilities DO. They don't invest on a gamble. And with renewables now producing as much electricity as nuclear in the US, it's clear that utilities have confidence in using these technologies.
Cling to whale oil lighting if you wish. But technology marches on.