we lease solar panels which where just fired up in Feb. I don't know where to put the upgrade of our electrical panel box to our main home
Unfortunately, an upgrade to your home's electrical service would not qualify for any tax credit or deduction and is not reported on your tax return. It would be an "improvement" to the property and its cost (materials and labor) would be added to the cost basis of the home.
"Leased solar panels" do not qualify for any federal energy tax credit. You would have had to purchase them in order to claim a tax credit. Some states, however, may provide tax incentives for leased energy efficient equipment.
From IRS Notice 2013-70
Q-15: May a taxpayer claim a credit for property that the taxpayer leases rather than purchases?
A-15: No. A taxpayer must purchase the qualifying property to claim the credits under §§ 25C and 25D.
Tesla now offers a rental instead of a lease and the electric panel upgrade is required to support the solar system, why wouldn’t this be covered as prep work for solar installation? From 5695 instructions: “ Include any labor costs properly allocable to the onsite preparation, assembly, or original installation of the residential energy efficient property and for piping or wiring to interconnect such property to the home.” I can’t claim the panel portion, but the box upgrade is strictly for the solar panels to connect properly to the house so is valid prep work and should count.
The labor and installation costs referred to in the Form 5695 instructions are part of the calculation used to figure the solar tax credit. As @ToddL stated in his answer, since your leased solar panels do not qualify for the credit, Form 5695 does not apply in your situation. In other words, you don't get to take a tax credit for costs associated with installing an unqualified system.
The tax credits and incentives belongs to the third party owner of your system.