Export Limiting: The Number on Your Interconnection Agreement That's Capping Your Solar Savings
Last updated: 2026-07-18
Somewhere in the stack of paperwork you signed before your solar system got permission to operate is a document called an interconnection agreement. Buried in it, usually as a single line item, is a number in kilowatts — your export limit. It's the maximum amount of power your utility will let you send back to the grid, full stop, no matter how much your panels are capable of producing on a bright afternoon. Most homeowners never see this number highlighted, never ask about it, and have no idea it exists until they start comparing their system's rated capacity to what their monitoring app shows on the sunniest day of the year — and the math doesn't add up.
This is the metric worth tracking that almost nobody tracks: not your production total, not your savings rate, but the gap between what your system could export and what your utility allows it to export. That gap has a name — curtailment — and on the wrong system, it's quietly erasing real production, and real money, every single day the sun is out.
What an Export Limit Actually Is
When your installer submitted your interconnection application, the utility didn't just approve "solar panels on this roof." They approved a specific arrangement: your system, your inverter, and a cap on how much power can flow backward through your meter onto their local grid at any moment. That cap exists for a real engineering reason — the utility has to make sure the local transformer and distribution line serving your neighborhood can handle the reverse power flow without voltage or safety issues, especially on circuits where several homes already have solar.
The export limit is typically expressed in kilowatts (kW), and it's set at the meter or at the inverter, depending on your utility's rules and your installer's configuration. Some utilities cap it at 100% of your system's inverter rating — meaning no real limit in practice. Others cap it well below that, especially on older neighborhood transformers or circuits already carrying a lot of residential solar. A homeowner with an 8kW system might discover their actual export limit is set at 5kW, meaning any generation above that ceiling, once your own household consumption is subtracted, simply doesn't go anywhere. It's not banked. It's not credited. It's clipped.
Why This Is Different From Panel Clipping or Inverter Clipping
If you've read about inverter clipping — where an oversized panel array feeds power into an undersized inverter and the excess above the inverter's rated AC output gets shaved off — export limiting can look similar on a production graph, but it's a completely different mechanism with a completely different fix.
Inverter clipping happens inside your system, between the panels and the inverter, and it's a design tradeoff your installer made on purpose to hit a certain DC-to-AC ratio. Export limiting happens between your inverter and the grid, imposed by the utility, and most homeowners never agreed to it in any meaningful sense — it was a condition of approval buried in paperwork, not a design choice explained at the sales table.
The practical difference matters because the fixes are different. You can't out-produce inverter clipping without changing your equipment. But you can work around export limiting — by using or storing the power you're producing before it ever tries to cross the meter, which sidesteps the cap entirely.
How to Find Your Actual Export Limit
This number doesn't usually show up in your solar monitoring app, because most consumer-facing apps show production and self-consumption, not the specific ceiling your utility imposed — see our guide on how to read your solar monitoring app for what those dashboards actually do surface. To find your export limit, you generally need to go to the source documents:
Check your interconnection agreement. This is the document your installer filed with the utility and that you likely signed near the end of your install process. Look for language like "export limit," "power export limit," or "maximum export capacity," usually expressed in kW.
Ask your installer directly. If the paperwork isn't easy to parse, your installer's project file will have the approved export limit on record — they had to design around it.
Compare it to your inverter's rated output. If your inverter is rated for, say, 7.6kW of continuous AC output and your interconnection agreement caps export at 5kW, you have a real, quantifiable gap — and on high-production days, that gap is where money is disappearing.
Watch your production curve on a clear, high-output day when household consumption is low. If your monitoring shows production flattening at a hard ceiling around midday on a day when the sun clearly hasn't peaked yet, and that ceiling doesn't match your inverter's rated capacity, that flat line is your export limit in action — not a cloud, not a system fault. If your current monitoring setup makes this hard to see, our roundup of the best solar monitoring systems covers which platforms make export behavior easiest to track.
Why This Rarely Comes Up Before You Sign
Export limits get set during the interconnection approval process, which happens after you've already committed to a system size and signed a contract based on projected production and payback. The utility's engineering review — checking transformer capacity, circuit loading, and existing solar penetration on your line — happens somewhat independently of the sales conversation, and by the time a limit gets imposed, the system design is often already locked in.
Installers aren't hiding this on purpose in most cases. Many neighborhoods have no meaningful export limit at all, so it genuinely doesn't come up. But on circuits with a lot of existing solar, or older transformers not sized for high reverse power flow, a real cap can get imposed after the fact — and because it's a utility-side condition rather than a component your installer chose, it's easy for it to never get flagged back to you in plain language.
What This Costs in Practice
The financial impact depends entirely on how much your system's peak production actually exceeds your export limit, and how often that happens. A system that rarely produces above the cap loses little. A system with a meaningfully undersized export limit relative to its DC capacity — common on larger systems installed on circuits with tighter utility restrictions — can lose a real percentage of otherwise-exportable production on sunny days, especially in spring and fall when household consumption is lower and more of the day's production would otherwise be heading to the grid.
Because curtailed power isn't credited under net metering (you can't get paid or banked credit for power that was never allowed onto the grid in the first place), this is pure lost value — not a billing dispute, not a metering error, just capacity that's being generated and then discarded because there's nowhere approved for it to go.
The Fix: Use It or Store It Before It Hits the Meter
Export limiting only caps power crossing the meter outward. It doesn't cap what you generate, and it doesn't cap what you use or store on your side of that meter. That's the entire workaround, and it's the reason this metric matters practically, not just academically:
Shift consumption to your peak production window. Running major loads — laundry, dishwasher, EV charging, pool pumps — during the hours your system is most likely to hit its export ceiling means that power gets used at home instead of getting curtailed at the meter. This is the free version of the fix.
Add storage sized to catch the surplus. A home battery or portable power station charging from solar doesn't count as an export — it's consumption, from the grid's perspective, even though the energy never left your property. Storage capacity aimed specifically at absorbing your curtailment gap, rather than just general backup power, converts power that would otherwise be discarded into power you use later, at night or during an outage. Our guide on how much solar battery storage you actually need walks through sizing against a production gap like this rather than a generic backup estimate. An EcoFlow system with expandable capacity is worth sizing against your specific curtailment gap rather than a generic "how many batteries do I need" estimate — if your gap is 2-3kW on sunny afternoons, that's the number to design storage capacity around, not your total system size.
For smaller households or partial backup needs, a Jackery unit can absorb a modest curtailment gap without the cost of a full home battery installation, particularly useful if your export limit issue is minor rather than severe.
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Common Questions About Export Limiting
Is export limiting the same thing as net metering going away? No. Net metering policy determines how you're credited for power you're allowed to export. Export limiting determines how much power is allowed to cross the meter in the first place. You can have generous net metering and still have a restrictive export limit, or vice versa.
Does every solar system have an export limit? Most interconnection agreements technically specify one, but on many systems it's set high enough — often at or near full inverter capacity — that it never becomes a practical constraint. It only matters when the number is set meaningfully below what your system can produce.
Can I get my export limit raised after installation? Sometimes, through a formal request back to the utility, but it typically requires a new engineering review of the circuit and isn't guaranteed, especially if the original limit was set due to real transformer or line capacity constraints rather than an arbitrary default.
Will my installer tell me if I ask directly? In most cases, yes — the approved export limit is part of their project file. It's a number worth asking for by name rather than assuming it will come up unprompted.
The Number Worth Adding to Your Checklist
You don't need to monitor your export limit daily, and for plenty of homeowners it will never be a binding constraint worth worrying about. But it's a two-minute check against a document you already have, and on the systems where it does bind, it's the difference between wondering why your production graph has a strangely flat ceiling and understanding exactly why — and what to do about it.
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SolarSimple does not provide financial or engineering advice. Export limits, interconnection rules, and net metering policies vary by utility, state, and circuit. Consult your interconnection agreement or a licensed solar professional for details specific to your system.