A rooftop solar system in Arizona may achieve payback faster than an equivalent system in Vermont because of the number of sunny days. While solar irradiance influences generation, the true driver of long-term solar ROI in the U.S is increasingly regulatory. Net energy metering (NEM) policies determine how much credit homeowners receive for excess electricity sent back to the grid, and these rules vary widely across states.
In many regions, declining export rates or credit values have made solar ROI a growing challenge for homeowners. As a result, even in states with strong solar potential, policy design can significantly extend payback periods and impact investment attractiveness.
This article compares net metering policies by state and explores how home energy management systems with battery storage emerge as a game changer to the challenge of reduced net metering value.
What to Look at in Your State’s Net Metering Policies
Net metering policies are generally structured around four core elements that determine the value of solar exports. Check these elements when looking at your state’s solar crediting rules.
- Compensation rate: Defines whether solar export is compensated for at the full retail rate, a much lower wholesale/avoided-cost rate, or a time-varying rate that pays you more during peak-demand hours.
- Credit rollover rules: Determine how unused credits are handled. They may roll over indefinitely, reset monthly, or be settled at an annual true-up where remaining credits are compensated at a lower rate.
- System size caps and eligibility limits: States may limit the size of an individual system based on household usage or a fixed kilowatt cap, or restrict total participation in the net metering program.
- Application and interconnection fees: Finally, there are soft costs. Interconnection review requirements, application processing fees, and upgrade costs can vary by utility and extend payback.
How Net Metering Policies Have Changed
Net metering in the U.S has evolved through multiple generations of policy design, moving from full retail compensation toward more complex, value-based export pricing structures that reflect grid conditions and solar penetration levels.
Full Retail Rate
Early net metering programs (often referred to as NEM 1.0) provided the simplest structure: excess solar generation was credited at the full retail electricity rate, and credits typically rolled over month to month. This made solar highly predictable and financially attractive, especially in early-adoption states.
Successor Net Metering: Added Fees and Time-of-Use Plan Requirement
As solar adoption grew, many states introduced successor policies (e.g., California’s NEM 2.0). Solar exports still earn credits at or close to the retail rate, but homeowners face time-of-use (TOU) billing, interconnection fees, and utility charges for grid electricity that solar credits cannot fully offset. As a result, solar value depends increasingly on when electricity is exported and consumed, not just how much is produced.
Net Billing: Avoid Cost / Wholesale Rate
The most recent shift, often called NEM 3.0 (notably in California), significantly reduces export compensation by moving from retail rates to avoided-cost or net billing values (what the utility would have paid for wholesale power). This change places greater emphasis on self-consumption and battery storage, as exporting solar energy to the grid is now worth substantially less than on-site usage.
How Net Metering Policies Vary by State
Net metering policies differ widely across the U.S, but most can be grouped into three broad categories: full-retail net metering, NEM 2.0-style policies, and net billing. The table below groups representative states by net metering category and shows how each policy model affects solar ROI. The following table represents policies at the time of publication.
| Policy Element | Full-Retail Net Metering | NEM 2.0-Style Policies | Net Billing |
| Representative states | DE, NJ, FL | CT, NC, NH, NV, NY, SC | AR, AZ, CA, HI, IL, IN, MI, MS, UT |
| Compensation rate | 1:1 full retail rate. Any surplus remaining at the annual settlement may receive a lower payout or expire. | Retail or near-retail credit, but monthly charges, reduced credit components, TOU pricing or other conditions lower their overall value. | Avoided-cost, wholesale-based or utility-determined rate, far below retail. |
| TOU plan required? | Usually No | Usually Yes | Usually Yes |
| Impact on solar ROI |
Favorable Stronger savings and shorter payback periods. |
Moderate Requiring careful consuming and exporting strategy. |
Challenging for solar alone Strong encouragement for battery storage. |
States with Full Retail-Rate NEM
States such as New Jersey, Delaware and Florida still offer policies close to traditional full-retail net metering, giving homeowners strong value for exported solar energy.
New Jersey provides full retail credit over the annual billing period. In Florida, for customers of investor-owned utilities such as Florida Power & Light, excess solar receives a one-to-one kilowatt-hour credit against electricity used from the grid. Credits roll forward for up to 12 months. However, any credits still unused at the annual true-up are converted into a payment at the utility’s much lower avoided-cost rate. Customers also remain responsible for applicable fixed or minimum monthly charges. Because these favorable policies can accelerate solar adoption, regulators may reduce export compensation in the future as participation grows.
States with NEM 2.0-Style Policies
States including Nevada, New York, North Carolina, and South Carolina fall into the NEM 2.0-style category. These policies still offer meaningful solar credits but reduce their value through slightly lower export rates, added charges, or TOU pricing.
Nevada credits excess solar at 75% of the retail rate, while New York retains retail-style net metering but adds a monthly charge based on system size. In major Duke Energy territories in North Carolina and South Carolina, exports can offset grid imports within the same TOU period. However, TOU tariffs make solar savings depend heavily on when electricity is produced, consumed, and sold back to the grid.
States with Net Billing
States such as Michigan have shifted to net billing, where solar exports are credited separately and usually at a much lower rate than grid electricity costs.
California is the clearest example. Under the Net Billing Tariff, or NEM 3.0, export credits are based on hourly avoided-cost values rather than retail rates, cutting average export compensation by about 75%. This makes midday exports far less valuable, extends solar payback, and makes it essential to install a home energy management system with battery storage.
Where to Find Your State’s Net Metering Policy
Net metering rules change frequently and may vary by utility. For the latest information, please check:
- DSIRE Database: State and utility-level renewable energy policies and incentives.
- Solar Energy Industries Association: State-by-state solar policy maps and summaries.
- Your State Public Utility Commission: Official tariffs, regulations, and approved utility programs.
Addressing the Declining Value of Net Metering
As export credits decline, the value of solar increasingly depends on using electricity at home rather than selling it to the grid. A home energy management system with battery storage can save excess daytime solar and intelligently use it during evenings or high-rate periods, increasing self-consumption and reducing grid purchases.
A home energy management system can also export surplus energy strategically when the compensation rates are the highest. The home battery in the system, which stores excess solar energy, when enrolled in virtual power plant (VPP) programs, will also bring more lucrative upfront and ongoing incentives. All these help significantly increase the value of solar and provide a hedge against future net metering policy changes.