I have had solar panels (10) installed on the south side of my garage for 4 years. I live in Illinois and one year the state gave a rebate as well as the their was a tax credit of $2000 that year. That made it more affordable. With the state rebate you had to be on the grid. They also buy back your excess electricity. Sounds like a good deal, right?
Well, it's not. I have yet to not receive a monthly bill. I think I average a savings of under $10 a month. Except for the refrigerator, there is nothing that draws electricity all the time. Anything that might draw electricity on a ghostly nature is not directly into an outlet but on one of those strips that you shut off entirely. The electricity the electric company buys back is at a reduced rate from what they charge me for their electricity. They installed a special meter and I can see it running backwards much of the time. So where the electricity goes is a puzzle to me.
In the winter with snow on the panels there is no electricity generated as well as the cloudy days. Also, you said you plan on living where you are forever. These panels only have a 25 year life expectancy and about halfway through their life, they start dying off. So, that might be something to think about. My panels were made in Arizona. Now China is a huge manufacturer of them. I don't know if they are made in the USA anymore. I don't know if that would factor into your decision.
The panels were installed on the garage because that faces south and that is the direction they need to be placed for the most sun, not the west as I believe you stated in another post.
But you are talking one panel on a shed. It might work fine for you. Let us know, please, if you choose to go that route and your satisfaction with it.