The (relatively) high cost is most likely because of labor and (in my opinion) inflated hardware costs of battery and solar panels.
Labor is a massive expense and can't be discounted but one could imagine a solar panel "kit" that just includes the hardware that you can install yourself.
One could also imagine that the costs of labor being subsumed by a larger entity that can take advantage of economies of scale and provide solar energy like a "classic" energy company. I believe something like that is already happening in the region where I live (upstate New York, USA).
For places where labor might be cheaper, then total costs would also come closer to raw hardware costs.
Installing high-wattage DC lines without any training at all is a great way to get house fires.
Also, I haven't got whole lot of un-shaded roof space.
I don't understand why commercial solar isn't even bigger than it is - are they waiting for prices to come down, or what?
> I don't understand why commercial solar isn't even bigger than it is - are they waiting for prices to come down, or what?
I think this is a really good question and I don't know the answer to it.
My not-very-well-informed opinion is that there are a confluence of factors involved:
* Infrastructure buildout, especially in the USA where the infrastructure projects take massive amounts of effort and the population is spread out over a large area of land, takes a lot of time, effort and money.
* The prices involved aren't as lucrative yet as they could be. When the price per MWh is 1/10 that of coal, then we'll see huge rollout (in my opinion).
* Adoption/rollout is happening but, in some places at least, there's government capture preventing widespread rollout/adoption (Pennsylvania?)
* Aging infrastructure prevents large scale energy injection at random points.
To the last point, here in New York state, I've heard one has to pay to first do a survey if the site where you want to build a solar array can actually inject that much more energy into the grid (at a cost of $10k+ or more) and even then, you're limited by what the aging energy infrastructure can support, capping the amount of energy available.
A cursory look on YouTube gives many results [0] [1] [2].
There are fields of ground mounted solar panels in the country side where I live.
[0] https://www.youtube.com/watch?v=7t4hGBWLtxM