Solar Panel Placement on Roof

Mounting the panels close to the roof will cause significant shadows and it's not necessary Every time I see a rig with the panels mounted higher I ask them what they have done. One of many options is to use used 2” aluminum square channel (like the kind used in sun rooms) and mount the panels at a height that shadows become a non issue, like 6” or more high. Mount the panels EW, the channel are mounted NS and considerations like rafters securing become a non issue. And with say a 6” high mounting the worst case rig orientation, shadows would be about 15 degrees of sun rise to no shadows and ditto for sun setting. Different rig orientations could reduce or eliminate the sun angle with shadows.

Here is a comparison of some possible solar configurations based on current Solar Blvd and Rogue costs.

1. 2 PV-SC150J12 panels 300/267W TS 45 controller. $476 (2*165+146) $1.59/W 21.4 sq ft parallel
2. 3 PV-SC150J12 panels 450/401W TS 45 controller. $641 (3*165+146) $1.42/W 32.1 sq ft parallel


1A. 2 PV-SC150J12 panels 300/291W Rogue MPT 2024. $605 (2*165+275) $2.02/W 21.4 sq ft serial or parallel
2A. 3 PV-SC150J12 panels 450/437W TS Rogue MPT 3048. $870 (3*165+375) $1.93/W 32.1 sq ft serial

The second watt number is the effective wattage due to the controller losses not counting wiring losses. 3% MPPT controller efficiency loss and an additional 8% PWM controller efficiency loss.

Here’s an expanded and more expensive setup:

3. 2 LG270 panels 540/523W TS MPPT 45 controller. $836 (2*203+439) $1.54/W 36.0 sq ft serial or parallel

Panel size: PV-SC150J12 58.2×26.4 LG270 65.67x39.3

With raised panel mounting there appears to be two locations for a third panel. More information would be required for further analysis.

Updated MPPT efficiency.