Washington RCW 80.60.010: Solar Net Metering Capacity Limits Guide

Key Takeaways

• Washington State's net metering law, RCW 80.60.010, caps individual system capacity at 100 kilowatts AC (August 2026).
• Utilities must offer net metering until June 30, 2029, or until cumulative capacity reaches 4% of their 1996 peak demand (August 2026).
• RCW 80.60.020 mandates bi-directional metering and prohibits additional fees for net metering customers (August 2026).
• At least one-half of the available net metering capacity is reserved for renewable energy systems (August 2026).

What are the net metering capacity limits in Washington State?

Washington State's Revised Code of Washington (RCW) Chapter 80.60 sets specific rules for net metering, including capacity limits for solar installations. Under RCW 80.60.010, a net metering system must have an electrical generating AC capacity of not more than one hundred kilowatts (August 2026). This is a statutory cap for individual systems.

Utilities are required to offer net metering on a first-come, first-served basis until one of two conditions is met: either June 30, 2029, or the date when the cumulative generating capacity of net metering systems reaches four percent of the utility's peak demand during 1996 (August 2026).

The table below summarizes the key statutory provisions:

| Fee Parity | "Shall charge the customer-generator a minimum monthly fee that is the same as other customers... but shall not charge... any additional standby, capacity, interconnection, or other fee or charge" | Figures as of August 2026.

How did we verify these statutory details?

We verified these details by directly consulting the official Washington State Legislature website. Specifically, we accessed and reviewed the full text of RCW 80.60.010 and RCW 80.60.020 on August 23, 2026. Our review focused on the exact wording of the statutes to ensure accurate representation of the legal requirements and definitions.

What does "first-come, first-served" mean for your solar project?

The "first-come, first-served" provision in RCW 80.60.020 means that eligibility for net metering is granted based on the order in which applications are received by the utility. This is important because utilities are only obligated to offer net metering until their cumulative capacity reaches four percent of their 1996 peak demand or until June 30, 2029 (August 2026), whichever comes first. If you are considering a solar installation, understanding these limits and applying promptly can be critical for securing net metering benefits.

The law also specifies a carveout for renewable energy systems: "Not less than one-half of the utility's 1996 peak demand available for net metering systems shall be reserved for the cumulative generating capacity attributable to net metering systems that generate renewable energy" (August 2026). This ensures a portion of the available capacity is specifically for renewable sources.

What are the requirements for a net metering system in Washington?

For a system to qualify as a "net metering system" under RCW 80.60.010, it must meet several criteria:

• It must have an electrical generating AC capacity of not more than one hundred kilowatts (August 2026).
• It must operate in parallel with the electric utility's transmission and distribution facilities and be connected to the utility's distribution system (August 2026).
• Its primary intent must be to offset part or all of the customer-generator's requirements for electricity (August 2026).
• The system itself is defined broadly to include fuel cells, facilities producing electricity and thermal energy from a common fuel source, or facilities generating renewable energy (August 2026).

The law defines "premises" as "any residential property, commercial real estate, or lands, owned or leased by a customer-generator within the service area of a single electric utility" (August 2026). This clarifies where net-metered systems can be installed.

How does Washington State protect net metering customers from extra fees?

Washington RCW 80.60.020 includes a "Fee Parity Protection" clause designed to prevent utilities from imposing additional charges on net metering customers. The statute states that utilities "Shall charge the customer-generator a minimum monthly fee that is the same as other customers of the electric utility in the same rate class, but shall not charge the customer-generator any additional standby, capacity, interconnection, or other fee or charge" (August 2026). This means you should not face extra fees simply because you are a net metering customer.

Furthermore, utilities "Shall allow net metering systems to be interconnected using a standard kilowatt-hour meter capable of registering the flow of electricity in two directions" (August 2026). This ensures that the metering infrastructure supports the two-way flow of electricity inherent in net metering without requiring specialized, costly equipment beyond a standard bi-directional meter.

How do Washington's net metering rules compare to other states?

Understanding Washington's specific net metering rules can help you assess your solar project's viability. The 100 kW AC capacity cap and the 4% of 1996 peak demand threshold are key figures to consider (August 2026).

For those with larger systems or considering multi-meter properties, Washington also has provisions for meter aggregation. You can learn more about this in our guide on Washington RCW 80.60.030: Meter Aggregation and March 31 True-Up Guide.

If you are evaluating solar options beyond Washington, comparing state-specific regulations is crucial. For example, you can review the net metering policies in Oregon PUC Solar Net Metering Guide or the Colorado PUC Solar Net Metering Guide. Each state has its own set of rules regarding capacity limits, compensation mechanisms, and program duration.

To estimate the appropriate size for your solar system based on your energy needs, you can use a solar sizing tool. This can help you determine if your planned system falls within the 100 kW AC capacity cap (August 2026) and aligns with the intent to offset your electricity requirements.