Note that DS30 answered a different question than the one you asked. You asked about the solar credit and DS30 talked about adding the expense to the basis of your home.
The Residential Energy Efficient Property Credit (form 5695 - https://www.irs.gov/pub/irs-pdf/i5695.pdf) no longer applies to insulation and energy efficient water heaters, unless they are solar water heaters.
As for tree trimming for solar panels, the instructions for form 5695 say "Qualified solar electric property costs are costs for property that uses solar energy to generate electricity for use in your home" (see link above). The tax credit is only for qualified solar electric property costs. A close reading of the law at Section 25D suggests that the expenses are allowed only for property that uses solar energy to generate electricity or is an integral part of such equipment (like the mounting hardware). In this case, tree trimming does not seem to qualify since it is not an integral part of the equipment that produces electricity from solar energy.
Yes, I see solar vendors make all sorts of claims about what expenses apply towards this credit; of course, they want to sell you services and are not tax experts.
TurboTax provides DIY tax services; that is, TurboTax depends on you to enter the data correctly, and it prepares the tax forms accordingly. If you want to make a claim for such a credit for foam insulation or tree trimming on the grounds that it can make your solar electricity system more efficient, I recommend that you find and use a tax professional who will guarantee your filing, i.e., will pay your penalties and interest if the IRS disputes your claim.
P.S. if you take this credit, you must reduce the basis in your home by the amount of the credit. See "You must reduce the basis of your home by the amount of any credit allowed" at https://www.irs.gov/pub/irs-pdf/i5695.pdf
