First off you need roofing skills, which 99% of homeowners have no idea how to do safely, often needs specialized equipment, and you run the risk of falling off and basically paralyzing yourself for life. Then you have the issue of having run conduit correctly, grounding everything to code, having disconnects installed in the right places, which is going to vary from state to state and even city to city based on what the laws are.

If you don't electrocute yourself, and manage to not fall off the roof and die, and somehow connect everything correctly, there is approximately 0% chance the local utility agrees to connect your system without a licensed electrician who is willing to vouch for the work you did.