Solar In Seattle Actually Works (On Paper)

I’ve always wanted to do solar but never could in the townhouse, with the pending purchase of a new home it was time to finally look into going solar. What I’ve discovered is solar is a complicated matter but a very fiscally smart move.

How Big an Array do I Need?

Solar arrays are measured in kilowatts but you pay for power in kilowatt-hours. There’s not a simple formula to relate the kilowatt solar array potential into kilowatt-hours produced because it depends a lot on your roof, equipment efficiency, and shading. For my roof estimates ranged from 750-915 kWh of annual generation per kW of panel.

Solar Incentives

Washington and Federal incentives are pretty strong, here’s the rundown for 2018:

  • Federal incentives are 30% of the system cost (see your tax advisor to check if you’re eligible) which comes at tax season, so you may have to wait a bit but a nice big discount nevertheless.
  • Washington (depending on your utility’s participation) will pay 18¢ per kWh produced (when using Washington made panels, 14¢ for other panels). This comes once a year for eight years, but is another big incentive. The maximum array size is 12kW for the residential program, which handles the power needs of most households.

Net Metering

Solar of course has bigger production months than others, net metering lets you balance out high production months and low ones. For example say you use 1000kWh/mo and in June you produce 1500kWh, that extra 500kWh is carried forward as a credit for the winter when production is lower. Note the credit resets each year and you’re not paid for any overproduction for the year.

But What Does it Cost?

So far my best quote is about $27k for an 11.68kW system. Its estimated to make about 9000kWh each year. Here’s how it pencils out:

$27000 purchase
$2322 sales tax (my rate is only 8.6%)
$-8100 federal rebate
$-12960 Washington State production credit (over 8 years)
$8262 net cost

But what I left out was not paying the utility. I pay 9¢/kWh for the first 600kWh and 11¢ for usage above that (which we use given two EVs). So for my average month of 880kWh I pay $85 in electricity (not including fees). With the solar array above on average I’d only buy 130kWh for $11.70. So after about 9 years utility bill savings will pay off the rest of the solar array – leaving decades of free green power to enjoy while increasing the value of the home.

So That’s the Cheap, What About the Green?

According to PSE our local power produces 1.11lbs of CO2 per kWh. This array will save nearly 10,000lbs of CO2 emissions annually. For reference that’s like about a car and a half worth of CO2 each year.

Hey That’s a Lot of Money!

While solar is a great deal, understandably you might not have 30k burning a hole in your pocket. I found Puget Sound Cooperative Credit Unit has a great program – its structured more like a car loan (many others are home equity loans) so your LTV doesn’t matter, the rates are below mortgage rates, and you can pay it down early with the incentives to lower your interest paid.

Quick CYA

The incentives listed are for the 2018 year and may not be available to you depending on income, power utility, and other factors. This is meant as an illustration of how solar works for us, your situation may be different.

Bottom Line

While jokes about Seattle’s rain and grey skies abound, solar power is actually a viable solution which makes financial sense to get a lower fixed cost of energy while greatly reducing environmental impact.

With any luck we’ll be installed this year and can report back next year on the outcome!

3 thoughts on “Solar In Seattle Actually Works (On Paper)

  1. Chad W says:

    What did you find out in terms of lifetime of the panels and batteries? If it takes 9 years to start truly saving, what will the system look like then?

    • kevin says:

      BTW I was also looking grid tied without batteries. Batteries generally come up only for off grid or grid tied with regular outages or time of use plans. PSE doesn’t do time of use pricing and outages hopefully won’t be common at the new place…but we’ll see. Fairly easy to add on later.

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