Quick definition
Some homes have a solar array that could produce more power than the local grid connection is rated to safely absorb. Rather than blocking that system entirely, a utility can set an export limit: a specific maximum power output, in kW, that the system is allowed to send back to the grid at any given moment. The system itself, using its home's actual usage, can still use as much of its own production as it needs.
This is a hardware-enforced setting programmed into the inverter, not a manual habit or a paper agreement alone.
At a glance: export limits are set per interconnection agreement and vary by utility, local grid capacity, and system size, so there's no universal standard number.
Why it matters
Local grid infrastructure, the specific transformer and feeder line serving a home, wasn't necessarily built with a large amount of two-way power flow in mind. An export limit is the tool a utility uses to let a homeowner install a bigger solar system than the local grid could otherwise handle uncapped, rather than rejecting the interconnection application outright, a process governed at the federal level by FERC's interconnection rules and implemented through each utility's own specific interconnection agreement terms.
Technically, this works through the inverter's own settings. Most modern grid-tied and hybrid inverters support a programmable export limit, often working alongside a power meter that watches the home's actual grid connection in real time. If the array is producing more than the home is using, and that surplus would push export past the set limit, the inverter throttles its own output to stay under the cap, even if the panels could technically produce more.
This is exactly where battery storage becomes valuable in export-limited situations. Power that would otherwise be capped and effectively wasted can instead charge a battery, storing that surplus for later use rather than simply losing it because the inverter held back production to respect the export limit. For the numbers behind Export limit, the levelized cost of energy calculator in our Savings & Payback section walks through the calculation step by step.
Where you'll see this
Before finalizing a system size, the grid export cap calculator checks whether your planned array fits within your utility's stated export limit for your service area. The grid interconnection cost estimator works out what connecting a system like this typically costs, including any upgrade the utility requires.
This term comes up specifically in interconnection agreements, in inverter configuration settings during installation, and any time a system's array capacity is larger than what the local grid connection is rated to absorb uncapped. DSIRE's database of state incentives and policies lists the export and interconnection rules that apply in each state.
Related terms
Frequently asked
Most modern inverters support a programmable export limit setting, often paired with a power meter monitoring the home's actual grid connection. The inverter throttles its output in real time to keep grid export below the set threshold, even if the array is producing more than that.
It can, if there's nowhere else for that excess power to go. A battery can absorb power that would otherwise be capped by the export limit, storing it for later use instead of it simply going unused.
They're related but different in scope. An export limit is a standing, ongoing cap built into a system's interconnection terms and enforced continuously by the inverter. Curtailment usually refers to a utility ordering a temporary reduction in output during a specific grid stress event, which can happen on top of a system's normal export limit.
Usually because the local grid infrastructure, like a specific transformer or feeder line, has a capacity limit that a larger uncapped system could exceed. Setting an export limit lets a homeowner install more solar capacity than the local grid could otherwise safely absorb.