With solar panels being so much cheaper than 10-15 years ago, it seems like installation costs are the biggest hurdle to wider adoption. Do you see anything reducing those costs in the future?
Maybe we need a push to make standing seam metal roofs more mainstream and people can install their own without having to drill into their roof
Soft costs are a majority of residential system cost [1], and there are some efforts to cram those costs down. One example is SolarApp [2], an automated permitting platform that directly integrates with local jurisdiction systems to streamline the permitting process (which was incubated at NREL [3]). Another are coop buys [4], where a community will open a registration window, and once a pool of buyers have committed, an RFP is put out of installers to bid to install the entire pool of systems. This drives down sales and marketing costs.
While I am a big fan of standing seam metal roofs for longevity reasons, they cost anywhere between 2x-3x the cost of a premium (architecture shingles vs 3 tab) asphalt shingle roof. This is due to increased labor costs to have the rolled steel cut and formed on site. If you could drive the down the cost (training and similar evangelism efforts sponsored by domestic steel manufacturers perhaps to stoke demand to replace other more volatile demand like auto sales), certainly friction based solar racking mounted to such a roof is superior to something requiring penetrations through the roof material and decking.
Regardless, we should assume most home owners are not going to do these installs themselves on their roofs. When new homes are built, solar installs should be required but in a way that makes the cost competitive vs unreasonable profit capture through whomever is building the home. When roofs are replaced, also an excellent time to have a solar PV system installed. These systems have a lifetime of at least 25 years, so it's important to have the stars align to make the choice as inexpensive and frictionless as possible when its made.
Maybe we need a push to make standing seam metal roofs more mainstream and people can install their own without having to drill into their roof