In this post, I will explain, why solar power might not be the final solution
Why solar power in the first place?
Solar energy is very interesting, isn't it? The sun sends down about 3.85 yotta joules of energy. To put this in a more usable perspective, you can recharge an iPhone 7 Plus 20.5 billion times with just a microsecond of exposure. So this is a lot of energy, but only about 13% of this is usable, at most. But that's still enough energy. So why isn't it the answer to our energy problem?
Storage of power
One of the most apparent reasons is the storage problem we have right now. A battery can store only a limited amount of power, and with current battery technology and pricing, this isn't the most viable solution.
In my opinion, the most interesting solution to this problem is melting salt. This process is used in the solar farms of Spain. In this process, nitrate salts are heated by the sun. The current technology can keep these towers up about 4 days without sun. This isn't really a viable option yet for consumers but could be the way to go.
Solar farm near Sevilla, Spain
Conversion losses
Another reason is conversion loss. Because our whole electricity network consists of alternating current generation and transportation, you can't just put direct current over these networks. That's where power inverters come in. But as with anything in the world, they aren't lossless. And these losses aren't insignificant. Most of the power inverters used today have a loss of about 5-10%.
TL;DR
So as you can see, solar power has still a long way to go. And it could very well be, that the consumption of electricity increases in the next decades. So solar could be rendered useless because it can't keep up with consumption. That's where fusion reactors come in. But they still are far away from adoption, and working for that matter. But doubts aside, I still hope solar power will be much more widespread.
Feel free to discuss this post in the comments below. I'll try to answer your questions if you have any. Also, this is just a piece of opinion, so yours may vary from mine. This should just be a little insight, so you get started and hopefully read more about solar power if you're interested.