OK, this one is specific.
Establish a regulation and/or pass a law that requires every new home/building and/or roofing project in the Southwestern United States to install full spectrum Solar Panels (on said roof) with the minimum capability to provide 110% of the estimated power output of the building. This cost could be written into the cost of building the home/building and offset by the homeowner not having any electric bill (maybe even earning money from the power company). The power companies in the Southwest could make profit by reselling said excess power on the grid.
This solves the grid connectivity problem, costs the taxpayers a very small amount (estimate a $10m/year oversight program), and will expand over time the capability of the United States in production of Solar Energy while reducing the load on the grid itself and "subsidizing" the Solar production and installation industry thereby putting more real capital into that market which will drive improvements and innovation in the industry. All with very little investment.