The batteries used to store solar energy are, by far the most prohibitive factor, but not completely so. Using the right deep cycle batteries, and proper maintenance means they last a hell of a lot longer than a few years. Mine are 7 years old, and are still holding at about 80% capacity. The real issue is technology. My batteries, as well as my panels are already outdated. I generate plenty of power, but if I were to replace my whole setup, I'd be able to collect a fair bit more energy. As it sits, my setup took about 5 years to pay for itself, and in the last two years I've put in about $400 in repairs, and saved well over $1200. That's a savings of $800 after I broke even. Not fantastic (it's actually only a savings of a little over $100 a year over the 7 year period), but ain't no kick in the teeth either. The point is, there is most definitely a savings (and as technology advances the savings improve), and the $$ aside, it's better for the environment (the mining/manufacturing involved has WAY less impact than drilling for oil). And if this is a discussion about future ways to improve life, then whether you're a tree hugger or not, the environment is a major factor.
At the moment, the most effective use for solar power would be using it on a smaller scale, like home electricity, rather than industry. By doing so, we free up a lot of the fossil fuels for industry, and use less of them, meaning they last longer, and become lower in price because the supply will catch up to the demand. Plus by using those resources while we still have them to produce the massive amounts of solar setups required to get started, we make the best use of non-renewable resources. Plus, once again, as the technology improves, the need for those fossil fuels will become less and less.
Just sayin.