Solar panels are getting cheap enough for grid hook-ups, installation and regulatory approval to become the bottlenecks.

Plug-in solar is suboptimal in many ways, but it does sidestep a lot of those hurdles. Not too surprised to see it on the rise.

Another thing that might be worth keeping in mind is that plug-in solar panels are often installed vertically - i.e. balcony solar. In which case the peak of the panel's generation is offset to the edge of the typical "duck curve". If it gets popular enough to affect the grid, it might get the solar-induced demand slump larger, but make the edges even sharper.

Would that make grid scale battery storage with its instant response even more important?

> it gets popular enough to affect the grid,

The plug in solar systems are small and usually mounted in ways that don’t capture as much energy as the same panels mounted on a roof. These systems aren’t going to get popular enough to make a big difference in anything.

I think it’s nice that they’re available for people to do some small scale offsets, but I think they’re more of a gateway to better solar installations. They also send people down the path of investigating battery storage add-ons, which might actually be a better long term solution for everyone.

If we can get to a point where we can buy plug-in batteries that are subsidized by requiring coordination with the grid, the power companies could get distributed, controlled battery storage to work with their demand curves. This can already happen with the bigger permanent install batteries.

Solar panel installation costs, at least in the US haven't dropped in 15 years. It's still $25-30k to install 4kW-6kW worth of solar panels.