Solar Panels Washington State 2022 Guide

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    Solar Panels Washington State 101

    Despite being known for rain, Washington is actually an excellent state for solar energy systems. Washington has some of the best solar incentives in the country, and the long sunny summer days mean that solar energy is actually very practical.

    In this article, we’ll take a look at how solar in Washington state actually works, how a home solar energy system can benefit you, and how many panels you might need to install.

    How Does Solar in Washington state Work?

    There are actually two different types of solar panels: photovoltaic (PV), which produces solar electricity, and thermal, which produces heat. In this article, we will be focusing solely on photovoltaic panels.

    A solar panel is made up of many individual solar cells, which are grouped together into a frame to create one panel. On the roof of a house, there are often many panels connected together, which makes up a solar array. When that array is then connected to an inverter and then to your home’s wiring, it creates a solar energy system.

    Other elements that may be part of the system include battery banks, charge controllers, and so forth that allow you to store the energy your panels produce for later use.

    Basically, solar panels are made up of silicon layers with positively and negatively charged elements like phosphorus and boron embedded within, which create an electrical field. When photons from the sun’s rays hit the panels, electrons are knocked free from atoms within the panels, generating an electrical current.

    Grid-Tied Vs. Off-Grid Systems

    Most home solar projects will be grid-tied. This means that the home is already supplied with energy from a local utility company, and the solar energy system will be a supplemental power source that helps keep your monthly energy bills down and can potentially provide backup power during a grid outage.

    Since net metering is allowed in Washington, you can sell any excess energy that your solar panels produce back to the local utility grid in exchange for credit that can be used against your future energy bills. This can be a great way to take advantage of the long sunny days of Washington summers to produce as much electricity as possible and sell it to the grid so you can use the credits during the short, dark winter days.

    However, there are some instances where solar energy may be the only source. These systems are called stand-alone or off-grid systems because they do not connect to an existing power grid.

    These systems are designed to charge an on-site battery bank, which then provides electricity during the night or whenever the panels aren’t actively producing power. This type of system is generally used in very remote or rural settings where there is no existing grid, or connecting to the grid would be extremely difficult or expensive.

    Are Solar Panels efficient in WA?

    There are several factors that impact the efficiency of a solar panel. Let’s look at the four most important factors. They are:


     The amount of sunlight that hits the panel has an obvious impact on how much electricity will be produced. Naturally, the number of sunlight hours the panel receives each day will vary based on the season and the weather, since there are many more daylight hours and generally sunnier days in Washington summers, while the winter days are often short and dark. However, solar panels have advanced technology that allows them to produce energy even from indirect sunlight on overcast or cloudy days.


    The average temperature of the panel’s location also affects the efficiency. Solar panels actually become less efficient the hotter it is. Every different type of panel has a temperature coefficient rating that tells you what percentage of power generation loss you can expect for each degree Celsius above 25 degrees Celsius (77 degrees Fahrenheit).

    Luckily, Washington has a moderate climate for the most part, so your panel efficiency will not be too badly affected.

    Type of Solar Panel

    Different types of solar panels have different efficiency ratings straight from the manufacturer. Most panels are rated between 15-20%, although some newer panels are now rated as high as 22%. As the technology continues to improve, the percentage will only go up.

    Angle and Orientation

    The angle at which your solar panels are mounted has a big impact on how well they produce as well. Solar panels are most efficient when the sun hits them straight on, with the sunlight at a perpendicular 90-degree angle from the surface of the panels.

    Here in Washington state, we are quite far north relative to the equator, so even during the summer, panels should be angled around 30 degrees to the south for optimal efficiency, and angled even steeper in the winter. This is most often achieved by mounting solar panels on a south-facing pitched roof.

    How Many Solar Panels Do You Need?

    The number of solar panels you need to power your home varies based on the size of your household and the amount of electricity you consume. The best way to determine how many panels you need is to assess your electricity consumption at different times of the year and then find the average amount in kilowatts.

    Once you’ve found your ideal number of kilowatts, you can cross-reference that number with your roof’s space capacity for solar panels and the number of sunshine hours that the panels will receive throughout the day and year.

    Generally, each kilowatt worth of solar panels will require about 100 square feet of south-facing pitched roof space. As a point of reference, most residential solar energy systems are between 4 kW and 10 kW in order to offset the majority of the home’s consumption.

    100% Offset Using Just 13 To 33 Solar Panels

    Then decide how much of that energy consumption you can feasibly cover by analyzing your roof’s capacity for holding solar panels and the number of sunshine hours the panels will receive.

    In general, each kW of solar panels will require 100 square feet of south-facing roof space. Residential solar energy systems commonly range from about 4 kW to 10 kW to generate 100% of the home’s energy consumption or 13 to 33 solar panels to offset your consumption by 100%

    Are Solar Panels Worth It in Washington State?

    Solar panels are certainly worth the investment for many Washington residents. Let’s look at some advantages and disadvantages.

    A Few Advantages

    Residential solar energy systems provide a renewable, clean source of electricity that can significantly reduce your carbon footprint and environmental impact. They can provide backup energy in the case of a grid outage, which can be lifesaving if you rely on electricity for medical equipment.

    Solar energy is becoming more affordable all the time, and there are many state, local, and federal incentives that help offset the initial investment costs. Solar panels generally have a lifespan of around 25 years and a standard home system can pay itself off in as little as 10-12 years, so you can then benefit financially from non-existent or very low energy bills for the remainder of the panels’ lifetime.

    A Few Disadvantages

    The disadvantages of solar panels are generally insignificant. However, the only two potential drawbacks would be that they are expensive to install and can be unsightly on your roof. But, incentives can cut the cost of solar installations by 50% and solar panel manufacturers are coming out with sleeker and more unobtrusive panels all the time.

    Is It Worth Getting Cheap Or Free Solar Panels?

    Generally, no. High-quality solar panels will last much longer than cheap ones and they will be more efficient. Solar panels are getting more affordable each year and when you apply solar incentives, the initial investment can actually be quite reasonable, even for high-quality panels.

    There are many different solar incentives that you can take advantage of in Washington, including the Federal Investment Tax Credit that allows you to deduct 26% of the total solar panel installation cost from your federal tax liability, net metering, sales and use tax exemption, solar grants, and the Washington State Renewable Energy System Incentive. 

    List of Washington Solar Incentives Solar Incentives

    1. Federal Solar Tax Credit

    2. Sales Tax Exemption

    3. Net Energy Metering

    4. USDA REAP Grant (Grants for large solar farms

    Considering Installing Solar Panels?

    Contact our team of solar experts at Sunbridge Solar today to get started with a free quote!

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