Roof needs solar panels

[msimerson]

reasons to do soon

1. WA state sustainable production incentives expire in 2020
2. 30% federal tax credit starts shrinking in 2019
3. WA state sales tax exemption

todo

• get quotes from installers
  • Sunergy: 9.90 kW for $30,424
  • NW Wind & Solar: 9.86 kW for $33,341
  • Puget Sound Solar: 8.1 kW for $32,762
• choose installer
  • schedule installation
• panel installation
  • permitting, ~7 days
  • Fill out SCL interconnection agreement
  • interconnection approval, ~7 days
  • install panels on roof (starting May 19th).
  • electrical inspection (May 24)
  • install new production and digital net meters, ~7-10 days (expected May 31, actual June 8)
    • get "made in WA" confirmation, 30 days (June 6)
• receive 30% Federal tax credit (Federal Tax Incentives #70)

options

• put panels on East/West facing garage roof
  • roof is nearly new
• put panels on South facing house roof
  • depends on two South roofs are aged #18 (replace roofing)

See also

• Roofing
• building code requirements at mybuildingpermit.com
• related to electrical system upgrades & capacity planning #15 (electrical system)

[msimerson]

Annual Solar Production for 98155 (modeled with PVWatts)

Azimuth	Tilt	Annual kWh
180	20	10675
180	35	10917
180	40	10875
270	5	9536
270	10	9539
270	20	9433
270	30	9199

[msimerson]

Payback Tracking

Year	Expenses	Rebates	Incentive(1)	Net Metering	Net Cost
2016	$33,341	$10,002	(#69) $688	$664	$21,888
2017			$3,633	$1,088	$17,004
2018			$3,778	$1,360	$11,661
2019			$3,815	$1,439	$6,192
2020			$3,500	$1,517	$948
2021				$1,517	$-859
2022				$1,621	-$2,736
.....				.......	..........
2030	$1,500			$2,066	-$14,187
.....				.......	..........
2046				$3,869	-$68,104
Totals	$34,841		$15,414	$67,416

1. The 2030 expense is an expected inverter replacement.
2. WA state renewable energy production incentive.
3. WSU Renewable Energy System Incentive Program
4. Senate Bill 5939

Notes

• Estimated annual electric rate increases are conservatively estimated at 4%. The 2017 and 2018 increases are 5.6%
• the production incentive is expected to diminish over time, ending in 2020.
• the net metering value increases in value as retail electric rates increase.
• future $ amounts should be inflation adjusted but are not. Yet.

[msimerson]

View from the South: