Susan, That is a great question. First , I applaud you for considering adding solar. I have had solar for 12 years now and am very pleased with the decision, for many reasons.

Yes, the magnolia tree can be pruned. Typically, magnolia tress are not that tall so keeping it below the point of shading solar panels should be doable. The proper method is to cut out the tallest branches. This will be thinning cuts, which is removing the entire branch back to the trunk or back to a lateral branch. Do leave the branch collar, the swollen area at attachment point. Do not leave a stub. You could remove up to 25-30% of the crown if that is necessary. If more will be required, then do it over 2 years. Here is a link to give more information on pruning: https://extension.umn.edu/planting-and-growing-guides/pruning-trees-and-shrubs#pruning-established-trees-1335962

Here is a link to hiring an arborist: https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional

I would not recommend moving the tree. I wish you the best with your project!

Paul -Tree Care Advisor volunteer