Getting Serious

Since I'd decided to be my own solar contractor it was time to get serious. The primary objective was to make sure that I was not overlooking anything — those 'gotchas' that can really make a hash of things.

So I dusted off my copy of Photovoltaics: Design and Installation Manual and did all of the exercises pertinent to my project.  Photovoltaics is an excellent book and the only recommendations I could offer would be 1) add more checklists, and 2) eliminate the "Solar Data" section (just put the latter on-line).

Everything checks out okay:

• House:
• 24 panels (3 strings of 8)
• Medium size inverter capable of handling ~350 VDC
• Inverter to be placed immediately adjacent to the main power panel
• Garage
• 16 panels (2 strings of 8)
• Medium size inverter capable of handling ~350 VDC
• Inverter to be placed next to the auxiliary panel in the garage

About this time, after visiting with some of the neighbors, I started thinking about cutting back to just the house-mounted portion of the system and leaving the garage as a possible future expansion.  There would be no real penalties for postponing the garage and there were a few minor benefits: 1) I wouldn't have to get Architectural Committee approval for the project, and 2) I wouldn't have to remove a tree:

The garage is on the right and this picture is taken facing to the south-southwest.  The tree immediately to the left of the garage shades the south-facing roof of the garage too much and would have to be removed.

The house will have a bit of a tree-shading problem from a large cottonwood tree located in the southwest corner of our lot:

This picture is taken facing almost directly east.  The cottonwood can be seen beyond the garage and is about 60' tall and growing taller each year.  It will cast a shadow on a portion of the house roof during non-summer days until about 11 AM.  The Enphase micro-inverters would help minimize the impact of that shading but since they are not available in the size I need I will consider using Tigo Energy's Module Maximizer or National Semiconductor's Solar Magic Power Optimizer, both of which can be retrofitted after the initial installation.

Having decided to eliminate the garage portion of the project I'm ready to move ahead.  That means getting a final equipment bid for the panels, inverter and railings and talking to my electrician.