How much do solar panels cost for an average home in the Seattle City Light service area?
The cost of installing solar panels in Washington varies with the brand of solar panels and inverters you choose, the installation company you choose to install them, the relative ease or difficulty of installing solar panels on your home, and of course the amount of solar panels you need to cover your electricity usage.
If we enter the details of a customer with an average SCL power bill into the Solar Estimate solar power calculator it shows that a 23.19 kW solar power system is needed to 100% offset usage, in kWh terms. (What is a kilowatt hour?)
The average cost of a solar system in the SCL service area, based on current local solar offers from solar companies is $2.4 per watt. This makes the cost of a standard 23.19 kW residential solar system $55,656 before the state and federal tax credits and $41,185 after tax credits are received. But don't stress, these days there are a myriad of competitive zero down solar finance options available.
See current live solar offers from your local installers
Are solar panels worth it for Seattle City Light electric customers?
There are three main reasons why installing solar panels for homes is so popular in Washington and specifically in the Seattle City Light territory. These reasons are:
- SCL customers can still take advantage of the 26% federal solar tax credit to install solar panels until it reduces at the end of 2020.
- SCL still offers a price close to retail power prices giving good value for excess solar power customers export to the grid (what is net metering and what is a feed in tariff); and
- Although winters in the north are cold and solar produces less than in the south, solar panels installed in Washington still produce a surprising amount of electricity over a year. This combined with some great local state incentives help to make the Seattle City Light territory one of the best places in America to install solar.
How much will solar panels save the average Seattle City Light residential customer?
The savings will vary depending on how much your power bill is now, the specific SCL rate plan you are on and how suitable your roof is for maximum solar generation.
If I enter the details again for Seattle City Light customers with an average power bill for a single family home into the best online solar panels calculator it tells me that I need a 23.19kW solar system that will produce 21,888 kWh's per year and that this system will likely return the owner a $45,499 profit even after repaying the capital over 25 years.
This is pretty amazing when you consider that you can get a zero down loan, contribute none of your own capital and still make such a big profit. When you compare this with the return on other home improvement projects this is seriously good. What's more this profit doesn't even include any capital value that solar panels may add to your home. This is just the utility bill savings.
How much will installing solar save a Seattle City Light customer in the first month?
Monthly savings year one $-72
The graph above shows the savings for this customer in the first month that their solar system is live. It assumes that the system is purchased via a 100% loan product.
One of the common reasons why people have been slow to install solar panels, despite the excellent financial return they can provide, is that often the first months savings may not appear to be enough to motivate them to go through the process of buying solar. Let's face it, we are all busy and we are only going to get off our backside and do a project where we can get a pretty big pay off for doing so.
However, it is important to realize that solar savings grow over time as utility prices increase. As can be seen in the graph below, the solar saving are quite considerable when totalled over the 25 year life of the system.
The overall lifetime profit will be even more with a cash purchase of the same system. The difference being that we have included the cost of interest in the lifetime savings summary below.
Estimated system size 23.19 kW (100% usage offset)
Pay Back Period
13 Years 1 Month
Equivalent Return on Investment (IRR)Equivalent Return on Investment (IRR)
How much roof space is needed for solar panels for the average customer?
The estimated south facing roof space required for the solar system referred to above is 1,546 square feet. Of course, your home is unlikely to be exactly the same as an average home. You may use more or less power than the household we have used in our example and also the characteristics of your roof may be such that solar power production from panels installed on your roof may be less than the electricity production from solar panels installed on a perfect, south-facing, unshaded roof.
Calculate how much roof space is required for solar panels on your home
How does the cost of solar power compare to the electricity rates charged by Seattle City Light? (per kWh)
Levelized cost of power from this system over 25 years is 8¢ cents/kWh.
Average cost of utility power over 25 years (if you don't get solar) is 19¢ cents/kWh.
System prices are estimated based on the average reported cost of systems installed in the past year. Pay Back Period and Equivalent Return on Investment are calculated based on a 100% cash purchase. Estimated Cost Per Watt is calculated after claiming all applicable incentives. This estimate assumes you are able to take full advantage of potential tax benefits.
Cash Flow graph - Cash Purchase of this system
Please keep in mind that the best source of up-to-date information on incentives are the solar installers who specialize in your area. If you still are unsure about the eligibility criteria of some of the solar incentive programs, please discuss with the solar installer representative who may contact your shortly, or visit the solar incentives discussion forum where the most common questions are likely to have already been answered.
Detailed information about your estimate
|System Size (for 100% usage offset)||23.19 kW|
|Annual Power Generation||21,888 kWh|
|Pay-back time (assuming Cash purchase)||13 Years 1 Month|
|Internal Rate of Return (IRR) on Investment||1.1 %|
|Total Upfront Incentives and Rebates||-$14,471|
|Net Cost of System after rebates and incentives||$41,185|
|Total Cost of Utility Power Avoided over 25 years||$105,345|
Please note that the investment return figures do not include the possible increase in property value.
How many solar panels are needed to power a house in Washington?
One of the first questions people ask when considering solar is how many solar panels do I need? The answer to this question depends on the power usage of the home, the location of the home and the suitability of the roof for solar electricity production. Some people are lucky enough to have a perfect south-facing, unshaded roof, but for many of us it is necessary to use parts of our roof that do not produce optimal generation. However, it is often possible to still get a very good return on investment from installing solar panels even if the annual generation from the panels on your roof is 10-15% less than optimal because your best available roof space is facing east or west.
Calculate how many solar panels you need for your home
What are the environmental impacts from Seattle City Light customers installing solar panels for their home?
While most home owners ultimately decide to install solar panels because of the financial savings they offer over time, for some people it is the environmental impacts of this choice that drive the decision. Here is a break down of the environmental benefits typically delivered by the installation of a 23.19 kW solar system in the SCL service territory.
A solar system generating 21,888 kWh per year will save you money AND make the world a nicer place
on average per year
Reduces CO2 emissions
metric tons per year
Equivalent to planting
Equivalent to driving
less per year
CO2 emissions calculation based on the electricity generation and emissions data for your state in 2015 as published by the US Government Energy Information Administration.
Why do solar savings for a typical Seattle City Light customer add up to so much over the life of a system?
Solar savings over the life of a solar panel system add up to much more than what most people think they will because of the enormous power of compounding increases in electricity prices over time. Even with modest annual increases of 3-4% per year over the 25 year life of a solar system utility electricity prices will grow by 240% over current Seattle City Light electricity prices.
|System Size||23.19 kW|
The above cash flow projection assumes a solar system that offsets 100% of power usage, a finance rate of 3.99%, a financing period of 20 years, a minimum utility charge equivalent to 10% of bill without solar, and a utility cost inflation rate of 4.5% p.a.
What is the average payback period for residential solar panels for an Seattle City Light customer?
The payback period for Seattle City Light customers installing solar panels on their homes depends on their power usage prior to installing solar, the finance method they choose to pay for their solar system, the size of system they install, the orientation and tilt of their roof and any shading that may affect output.
What we have done above is copy an extract from our SCL solar panel savings calculator which shows the payback period for a typical SCL customer. You can visit this calculator above and enter your own current power bill to see your solar savings and your likely payback period. You'll note that for customers with larger monthly power bills the payback time is usually slightly shorter because the cost of solar systems per watt usually reduces as the system size increases.
See your savings and payback period based on your electricity use and location
How much electricity do solar panels produce in Washington?
Who are the best solar companies that service my local part of Washington?
Washington has a very competitive retail solar installation market with many solar panel installation companies fighting hard for your business. This is why it's important to shop around and research solar companies in your area. The way to find the best solar company to install solar is to read reviews of solar companies in Washington.
As the Seattle City Light territory covers a number of cities there are different solar companies operating locally in each, as well as some that cover the whole territory.
How do I get accurate solar quotes that take into account my power usage with Seattle City Light?
To get accurate solar quotes you (or your solar company) needs to work out how many solar panels you need on your home.
To do this they need to know your power usage patterns. This will allow you to come up with the amount of solar panels you would ideally want to make your power bill zero. See below for ways that you can get hold of your power usage data either for your own analysis or to share with a solar company that you wish to have quote your home.
Once you determine the right amount of solar panels you then need to measure your roof to see how many panels will actually fit on your roof. Most solar companies can measure roof spaces online using tools that are similar to Google Maps (but are more accurate) such as www.nearmap.com.
The www.solar-estimate.org website is the leading solar marketplace in America and allows you to both do an accurate online estimate of your needs yourself and, if you wish, request quotes from solar companies through one interface.