Can you install solar without net metering? Non-export rules, approvals and the self-use math

Four rulebooks for a system that never exports

Non-export is not one national rule. It is a branch inside each state's interconnection procedure, and the branches differ on three points that matter to a homeowner: how big the system can be, what counts as proof that it will not export, and whether household load can be part of that proof. The table sets four official documents side by side, each read in full for its non-export provisions.

None of the four treats a zero-export promise as permission to connect without telling anyone. Three still run an application with a written answer, and the fourth, Hawaii's self-supply program, has stopped taking new customers altogether. The real variable is how much the utility trusts the equipment. California will take a sizing argument for small systems; Minnesota's municipal booklet refuses one outright and insists on certified controls.

The same pattern holds outside these four. Before you design around a non-export path, find your own utility's interconnection procedure, search it for "non-export" or "export", and read the options it lists. If the document has no such branch, the standard application applies and the system is reviewed as if it could export.

California's export screen: six ways to promise zero

Rule 21 handles the question in a single screen. Screen I asks: "Will power be exported across the PCC?", the point of common coupling where your wiring meets the utility's. Answer yes and the review continues to Screen J, with the inadvertent and limited export options (5, 6, 9, 10 and 11) still in play. Answer no and the facility must use Option 1, 2, 3, 4, 7 or 8; once one is selected, Screens J, K, L and M are skipped and Initial Review is complete. The significance note under the screen gives the reason in plain terms: if the facility cannot export, the grid does not need to be studied for load-carrying capability or for power-flow effects on voltage regulators.

The four relay and sizing options are written as numbers, and each translates into something concrete on a house. The table applies the tariff text to inputs typical of a detached home. The service and transformer sizes are illustrations rather than your utility's records, and the conversion of the ampere test to kilowatts at 240 volts is our own arithmetic, not a figure printed in the tariff.

Option 3 deserves a careful reading because it is the only route with no relay and no controller, and it has two limits that can bite. The service rating used is the one the service was originally sized for or an upgrade the utility approved, and the tariff says plainly that it does not intend to allow more export simply because a customer installs a larger service panel without separate approval for the resize. A main panel upgrade done for solar therefore does not lift the Option 3 ceiling by itself. The transformer test uses the utility's transformer, which may be shared with neighbours; only the utility can tell you its rating.

Option 2 has an operating cost that installers rarely mention. A minimum-import relay set at 5% of an 8 kW system's gross rating means the home buys at least 400 W from the grid every moment the array is producing. Over a sunny afternoon that is energy you pay for while panels sit partly idle, and it lowers the ceiling on the self-use share any Option 2 system can reach.

Option 4 explains why sizing to load rarely works for houses. It allows generation up to half the lowest load the home has drawn over a year, and a household's lowest hour, at night with the refrigerator cycling, is usually a few hundred watts. That leaves room for a panel or two, not a rooftop array.

The notification-only claim, checked against PG&E's own forms

Vendor glossaries say that under Rule 21 a non-export system needs only a notification rather than an application. The tariff body does not say that. Its general text routes every non-exporting facility to Fast Track review, and the words "notification-only" appear only in its index of forms, as two entries: Form 79-1212, the Rule 21 Non-Export Generator Interconnection Notification, and Form 79-1214, the Notification-Only Pilot Program Developer Eligibility Application. Both forms were added through Advice 6249-E-B under CPUC Decision D.21-06-002, effective July 19, 2021.

The forms describe a pilot with tight gates. A system qualifies only if it meets every one of nine conditions: total size of 30 kVA or less; one new non-export storage system, one new non-export system combining storage and solar, or new non-export storage added to an existing non-export facility; no more than ten notification-only projects on the circuit from the same developer; a UL-certified power control system with an open-loop response time of 2 seconds or less, set to non-export; a 120 or 240 volt service with a self-contained meter; a location off PG&E's networked secondary system; operation that does not increase the customer's peak load; inverters pre-approved by PG&E; balanced output across both legs of a 240 volt service; and installation by a developer PG&E has already approved.

Two of those conditions decide most residential cases. Solar on its own is not on the list of eligible configurations, so a panels-only array does not qualify; every eligible configuration contains storage. And the installer, not the homeowner, has to be on PG&E's approved list. The developer's attestation on Form 79-1214 states that the company has already deployed 20 non-export projects meeting the pilot criteria through PG&E's standard interconnection process. A contractor without that record cannot file under the pilot at all.

Even inside the pilot, PG&E reviews. Form 79-1212 says it is sent with a single-line drawing, a signed customer agreement and attestation, and evidence of final electrical inspection from the local building authority, and that PG&E will check the documents for completeness and eligibility and issue a deficiency notice within 15 days if anything is missing. The forms remained in the Rule 21 forms index in the tariff book downloaded October 31, 2026. Ask the installer to confirm in writing that the pilot is still accepting projects before relying on it. So the vendor claim survives only in a narrow form: notification-only exists in PG&E territory as a storage pilot for approved developers, not as a general rule for non-export solar.

What the controller must do, and the export the rules forgive

A modern zero-export system is usually a battery inverter or hybrid inverter with a power control system: a controller that measures the flow at the meter or the main panel and throttles the inverters when the house load falls. Rule 21's Option 8 sets the minimum performance. The controller must pass the 2019 Underwriters Laboratories Power Control Systems Certification Requirements Decision test protocol, or later revisions of it, and the testing lab must have found that it conforms to the non-exporting function. It must be certified with an open-loop response time of 2 seconds or less and reduce export to zero or less within 2 seconds of export starting; a unit with that response time and a time to steady state of 10 seconds or less meets the rule. It must be set to zero export and paired only with UL 1741 listed grid-support inverters.

Minnesota's booklet names the newer listing as well: UL 1741 PCS or UL 3141 for power control systems, and UL 1741 SB or SC for inverters whose own non-export setting is used. New York's SIR asks for inverters certified to the most recent revision of UL 1741 including Supplement SB, with the utility's settings, and requires reverse-power protection, ANSI device 32, wherever net export is limited. These listings sit on top of IEEE 1547-2018, the interconnection and interoperability standard for distributed energy resources. The IEEE Standards Association lists it as an active standard, approved February 15, 2018, published April 6, 2018 and amended by 1547a-2020, with a revision project, P1547, under way. A specification sheet should name the listing and its edition; a vague "zero-export capable" line is not evidence.

No controller reacts instantly, so the rules distinguish a true non-export design from one that tolerates brief backfeed. Rule 21 Section M calls the short, uncompensated export that happens when load drops faster than a generator can ramp down "Inadvertent Export". It caps the amount at the lesser of 50% of the facility's capacity, 10% of the weakest upstream feeder conductor's continuous rating, 110% of the largest load block, or 500 kW or another utility maximum. It requires a reverse-power function that trips within 2 seconds if that amount is exceeded, expects fewer than two such events per 24 hours, and requires a second function that trips the generator if any export lasts more than 60 seconds. Options 5, 6, 10 and 11, which allow inadvertent export, go through the exporting branch of Screen I. The kilowatt-hours that leak out under them earn nothing.

For a homeowner this means a system sold as zero-export can be filed in two different ways. Under Option 8 it is non-export, skips four screens and must hold export at zero. Under Option 10, with a slower controller of 2 to 10 seconds, it is non-export with inadvertent export and is reviewed as an exporting system. The installer's application form shows which option was chosen, and it is the line to read before anyone tells you the review will be short.

Flipping the zero-export setting without the utility's approval

Switching an inverter to its zero-export setting and turning the system on before the utility has answered. PG&E's agreement for non-export facilities of 30 kW or less says that, apart from systems eligible for the notification-only pilot, the customer may not operate the generator while connected to PG&E's system until it has written permission, and it warns that unauthorized parallel operation could leave the customer liable for injury or damage. Minnesota's municipal booklet goes further after approval: the utility may disconnect a system whose nameplate rating, capacity rating or export capacity has been changed from the application without its approval. A firmware setting is not the approval, and changing it later can undo one.

New York and Minnesota: stricter on proof, plainer on paperwork

New York's SIR covers new generators and storage of 5 MW or less connected in parallel with a utility distribution system, and states that generation or storage neither designed nor operating in parallel is not subject to it. A zero-export rooftop array still runs in parallel, because the house draws on both sources at once, so it goes through the ordinary process. For systems of 50 kW or less no application fee is charged, the package is filed through the Interconnection Online Application Portal, and the utility has ten business days from receipt to decide whether it is complete, meets the technical requirements and can be approved. The protective-function table asks for reverse power wherever net export is limited, and the utility may add functions case by case if it explains the need in writing.

Minnesota's municipal booklet is the most explicit of the four about what does not count. It opens by saying that the electric load of a service cannot be used to qualify a system as non-exporting, because load varies with usage and is not a reliable guarantee, so a system needs certified controls and must provide its settings to the utility. That rules out the kind of sizing argument California accepts in Options 3 and 4. The process covers inverter-based systems up to 100 kW AC, may be used to add a non-exporting component such as a battery to an existing system, and is open only to certified equipment. Uncertified gear goes to the Fast Track process instead.

The booklet also sets out duties that run for the life of the system. The customer carries general liability insurance of at least $300,000 below 40 kW AC and $1,000,000 from 40 kW to under 100 kW. Any metering the system needs is installed at the customer's expense, and the utility may charge an ongoing metering fee for costs it can demonstrate. The utility can disconnect a system that stops following its approved IEEE 1547 settings or no longer meets the non-export requirements. None of this is unusual for interconnection, but it is easy to miss when a system is described as needing no permission because it sends nothing to the grid.

What a California non-export bill still carries

Leaving net billing does not take a PG&E customer outside the utility's charges. Schedule E-DCG, Departing Customer Generation, applies to customers who displace all or part of their load with their own generation, and it treats the displaced usage as departing load. Unless an exemption in its Special Condition 2 applies, that usage is subject to a list of nonbypassable charges, including the Wildfire Fund Charge, Power Charge Indifference Adjustment, Competition Transition Charge, Nuclear Decommissioning Charge and Public Purpose Program Charge. The exemptions that once covered small clean generation, including systems eligible for the California Solar Initiative, are Special Conditions 2.c to 2.f, and they expired on February 12, 2015, when cumulative exempt departing load passed a 3,000 MW cap counted by the California Energy Commission.

The schedule also sets a procedure. A customer must notify PG&E in writing at least 30 days before the load departs, giving the date, a description of the load, the account number, the generation technology and any exemption claimed. PG&E then has 20 days to send a Customer Generation Departing Load Nonbypassable Charge Statement. Failure to notify is described as a violation of the tariff. The statement confirms or rejects any exemption you claimed, and together with the schedule's rates it sets the departing-load cost for your account, the D input in the arithmetic below. The rates themselves are utility rate content; read them on the statement and on EnergyBS's rate-plan guide rather than from a summary.

There is also no export credit to settle. A non-export account does not build up the monthly credits that end in a net billing true-up, so the year has no settlement month and no surplus payout. The fixed charges on the otherwise applicable rate schedule continue as for any customer. Hawaii's closed self-supply program said the same thing more bluntly: no credits, and minimum billing applies.

One California case is covered elsewhere and is not repeated here: a non-export array added to a system that keeps a grandfathered NEM or NEM2 rate. That route, PG&E's description of it in Advice Letter 7915-E and the departing-load billing proposed for it are worked through in the guide to keeping grandfathered net metering after an addition.

The self-use test: when giving up the export credit is the cheaper side

With the same array on the same roof, the kilowatt-hours the house uses at the moment they are made are worth the same retail price under any arrangement. Non-export changes only the rest. Under net billing the surplus earns the export rate; under non-export it is curtailed and earns nothing. So for an identical system, non-export can never earn more energy value than net billing. It wins only when it avoids a cost the export tariff carries, or when the export credit is close to zero.

Written as a rule: let P be the array's yearly production with nothing curtailed, s the share of it the house uses as it is produced, e the export credit per kilowatt-hour, D the yearly departing-load charges that apply only under non-export, and A the yearly costs the export route carries that non-export avoids, such as a required upgrade spread over its life or a tariff-specific monthly charge. Non-export comes out ahead when A is greater than P x (1 - s) x e + D. Every input except P comes from your own bill, your tariff or your interconnection paperwork. None of them is a national figure, and the self-use share in particular has to come from your interval data or the installer's model, not from a rule of thumb.

The table puts numbers on the first term for one array. Production is a PVWatts 8.5.0 run for 8 kW DC in Los Angeles, south-facing at a 20 degree tilt with 14% losses: 13,417 kWh a year. The array's price is the $2.95 per watt DC that DOE's Q1 2025 cost model gives an 8 kW system, $23,600 in 2024 dollars, and its upkeep is the same model's $34 per kW per year, or $272. The 30-cent retail rate and the 5-cent and 8-cent export credits are labelled inputs, not any utility's current prices, and the self-use shares are reader inputs. No tax credit appears anywhere in the math.

The gap closes quickly as self-use rises. At 40%, curtailment costs $403 a year at a 5-cent credit and stretches payback by four years; at 80% it costs $134 and adds a few months. In the 60% row, 13,417 x 0.6 = 8,050 kWh used on site, worth $2,415 at 30 cents; less $272 of O&M leaves $2,143, and $23,600 divided by $2,143 is 11.0 years. Adding 5,367 kWh of exports at 5 cents, $268, gives $2,411 and 9.8 years. Neither column includes D. In California, the departing-load charge on each self-used kilowatt-hour has to be subtracted from the non-export side before the comparison means anything.

Read the payback columns as a ranking of options for the same hardware, not as a forecast. Retail prices move, export rates are revised, and production differs by roof, which is why reading the installer's production estimate comes before any of this. The structure holds across those changes: the lower your self-use share, the more an export credit is worth keeping.

One roof, two designs: 8 kW on net billing against 4 kW at zero export

A Los Angeles household is offered the 8 kW array from the table on net billing. Its interval data shows that about 40% of that array's output would be used as it is produced. The same installer offers a 4 kW non-export system with a certified power control system, sized to the household's daytime load. The inputs are the ones used above: PVWatts production, the DOE benchmark price, $34 per kW per year O&M, a 30-cent retail rate and a 5-cent export credit, all labelled illustrations.

Scaling the PVWatts run, 4 kW produces 6,708 kWh a year. If the household's data shows it would use 90% of that, 6,038 kWh, the self-used energy is worth $1,811. Less $136 of O&M (4 x $34) leaves $1,675. Priced at the benchmark, 4 kW is $11,800, and $11,800 divided by $1,675 is a simple payback of 7.0 years. The 8 kW array on net billing, from the 40% row, pays back in 13.6 years.

Two cautions keep this honest. The DOE benchmark is modeled for an 8 kW system, and a 4 kW system usually costs more per watt because permits, design and labour do not halve, so price the actual quote per watt using the solar cost guide before trusting 7.0 years. And the smaller array uses 6,038 kWh a year, against 5,367 for the larger one at 40%, so on these inputs it covers only slightly more of the home's own consumption; the gain is in cost, not in coverage. In California the departing-load charge on those 6,038 kWh still has to come off the $1,675 before the comparison is final.

Batteries change the arithmetic, and the paperwork with it

A battery is the usual way to make non-export work, because it turns curtailed midday output into evening self-use. Every eligible configuration in PG&E's notification-only pilot includes storage, and Minnesota's booklet names batteries, and renewables combined with batteries, as the systems its non-export process is built for. In the self-use rule above, a battery raises s. Each kilowatt-hour moved from the curtailed column to the used column gains the retail rate, less the battery's round-trip losses.

It also changes the cost line. The DOE benchmark for the same 8 kW system with 13.5 kWh of storage is $4.59 per watt DC, $36,720 in 2024 dollars, or $13,120 more than the PV-only line. Whether that premium pays back depends on how many surplus kilowatt-hours the battery can actually shift each day and on the gap between the retail price and the export credit it replaces. The battery decision guide works that question with its own inputs, and the home battery cost guide prices storage capacity against the same benchmark.

Storage brings its own rules. Rule 21 Section D.14 gives non-export storage facilities that meet the Section N criteria the option of expedited processing and a matching agreement form. A battery added later to an existing system falls under Rule 21's provisions for modifying a generating facility, a path covered in the guide to adding a battery to existing solar. And a battery set to zero export still needs its own backup wiring and transfer equipment if it is meant to run the house in an outage; non-export describes what crosses the meter, not whether the house stays lit, a distinction set out in the outage guide.

Where a zero-export design earns its place

Non-export makes the most sense in four situations. The first is an export credit so low that the lost value in the table is a rounding error next to the costs the export tariff brings. Compare your own rule using the explainer on net metering and net billing and, for California, the California net billing guide. The second is a circuit where exporting systems face long studies or upgrade costs. Rule 21 skips the load-carrying and voltage-regulator screens for a facility that cannot export, and Hawaiian Electric's program page said its self-supply systems were eligible for expedited review even in areas with existing voltage limitations.

The third is a home whose daytime load is large and steady enough that the self-use share is high anyway: a home office running all day, a pool pump on a daytime schedule, an electric vehicle charged at midday. The fourth is the grandfathered addition case, which has its own guide. For everyone else, non-export trades a modest, measurable credit for a design that throws away output, and the self-use test above says how much.

Two neighbouring ideas are often confused with it. A system with no utility connection at all is off-grid rather than non-export, and it carries the full cost of storage and backup generation, priced in the off-grid solar cost guide. A balcony or plug-in kit is a separate product category with its own state laws, covered in the plug-in solar state guide. Neither is what a utility means by a non-export interconnection.

The application file for a zero-export system

• The interconnection procedure your utility uses, and the section or option number it applies to non-export systems.
• Which option the application will select (in California, Screen I Option 1, 2, 3, 4, 7 or 8), and whether the design is true non-export or non-export with inadvertent export.
• The listing and edition of the power control system and inverters (UL 1741 PCS or UL 3141, UL 1741 SB), with the open-loop response time from the data sheet.
• Your service rating and, from the utility, the service transformer rating, if a sizing option such as Option 3 is proposed.
• Twelve months of interval data, and the self-use share the installer's model assumes for this array size.
• In PG&E territory, the Departing Load Nonbypassable Charge Statement, or the utility's written estimate of it, and the 30-day notice date.
• The fee invoice under the utility's fee table, and any metering, insurance or upgrade costs the utility lists.
• If a notification-only filing is proposed, written confirmation that the installer is an approved pilot developer and that the pilot is still open.