Company 2 pricing is higher because they exclusively use SunPower products and use micros instead of optimizers:
Parents 7.848 kW ground mount:
$30,810 total cost = $3.93/W
10,270 kWh annual production
$1,232 annual value of solar production @ 12 cents
Oregon incentive -$5,000
Energy Trust -$9,000
Out of pocket $16,810
Federal tax credit -$4,371 @ 26%
Net $12,439 $1.58 watt
10 year payback from electricity alone assuming no inflation
SunPower SPR-E20-327 x24
String inverter Fronius Primo 5kw
My roof mount 5.559 kW roof mount:
$18,890 Total cost = $3.40/W
6,825 kWh annual production
$819 annual value of solar production @12 cents (4% less than above)
Oregon incentive -$1,112
Energy Trust -$1,668
Out of pocket $16,111
Federal tax credit -$4,189 @26%
Net $11,922 $2.14/w
14.5 year payback from electricity alone assuming no inflation
SunPower SPR-E20-327 x17
Sunpower Micro-inverter SPE-E20-327 x17
The very tempting yet dangerous sounding option is Tesla. Here's the online quote:
My roof mount
7.6 kW TESLA roof mount:
$17,000 Total cost = $2.24/W
? kWh annual production
At least $962 annual value of solar production (100% of my current usage)
Oregon incentive -$1,520
Energy Trust -$2,280
Out of pocket $13,200
Federal tax credit -3,432$ @26%
Net $9,768 $1.29/w
10 year payback from electricity alone assuming no inflation
Tesla doesn't list components used, and many people online say they use string inverters unless there is enough shading to justify optimizers, and it's unclear if that affects pricing. The real downside is the consistently scathing reviews left by customers even until recently. Difficulties getting attention of customer service, and waiting months to get problems fixed. Some reports of roof leaks following installation. It's unclear if they put in the effort to get the utility and state credits because that isn't quoted in the price. Probably not worth the risk to save a few bucks.
Tesla reviews:
https://www.solarreviews.com/manufacturers/tesla
EDIT: 2 more adjusted quotes from Company 2:
Parents 6.32 kW ground mount:
$24,740 total cost = $3.91/W
10,042 kWh annual production
$1,205 annual value of solar production @ 12 cents
Oregon incentive -$5,000
Energy Trust -$9,000
Out of pocket $10,740
Federal tax credit -$2,792 @ 26%
Net $7,948 $1.26 watt
6.6 year payback from electricity alone assuming no inflation
SunPower SPR-P19-395 x16
String inverter Fronius Primo 5kw
My roof mount 5.695 kW roof mount:
$18,960 Total cost = $3.33/W
7,065 kWh annual production
$847 annual value of solar production @12 cents
Oregon incentive -$1,139
Energy Trust -$1,709
Out of pocket $16,111
Federal tax credit -$4,189 @26%
Net $11,923 $2.09/w
14 year payback from electricity alone assuming no inflation