Solar panel changes, installation in one week!

Previous posts in this series:

• On Modeling the Economics of Residential Solar
• Solar power installer selected!
• Three solar power proposals
• A financial model for residential solar power

We’ve been given a date of September 19 for the installation start!

And we’ve had two small hitches…

After an internal review, A&R Solar needed to adjust the roof panel layout. We’ll have the same panel count as the original contract but in a slightly different configuration. There isn’t a noteworthy change in the projected energy generation, so this was of no significance except for signing a change-order form.

The second hitch is noteworthy. Panasonic photovoltaics now have a supply-chain problem and the 410W panels are temporarily unavailable. Temporarily means, “We don’t know when they’ll be available.” I’ve read posts on /r/solar mentioning this issue, so it’s not just a local situation.

We’ve been switched to REC 405W panels. The projected energy output is 1.2% lower, for a slightly higher price. I’m guessing the higher price stems from signing an order for them now vs. a couple of months ago; supply chain problems rise prices everywhere over time.

But I’m content to move this along and although the 410W would have given me bragging rights amongst online photovoltaic cognoscenti, I’m happy with 405W.

The system’s projected numbers now are:

• Thirty-one REC Alpha-Pure 405W panels
• SolarEdge
• Power: 12.56 kW
• Annual energy: 10,400 kWh in year 1
• Installation cost: $42,145
• Cost / Watt before Federal tax credit: $3.36
• Installation cost after new 30% Federal tax credit: $29,502
• Annual projected energy savings in year 1: $1,284