Export limits allow you to control how much solar energy your system is allowed to send back to the grid. Many utilities require export caps to prevent grid overload, and this feature ensures Aurora’s simulations and reports respect those limits.
With this release, Aurora introduces:
- System-level export limit support
- Curtailment reporting in charts and summaries
- A self-consumption battery mode that minimizes curtailed energy under an export limit
What Are Grid Export Limits?
Export limits are utility-defined caps on the maximum instantaneous power (kW) a property can export to the grid. For example, if the export limit is 3 kW, any generation above that amount cannot be exported - it must be consumed onsite, stored, or curtailed (reduced). This feature reflects export limits in simulation.
How Aurora Handles Grid Export Limits
When you set an export limit:
- Aurora enforces the cap in avoided cost simulations
- Solar generation above the limit is either:
- Stored in available battery capacity, or
- Curtailed (reduced) if it cannot be stored
- Curtailment is reflected visually in energy charts and annual summaries
New Self-Consumption Battery Mode
In addition to standard export limit behavior, we have added a new consumption schedule called self-consumption (min curtailment). This consumption schedule…
- Prioritizes maximizing self-consumed solar
- Adjusts battery charging timing to reduce or eliminate curtailment
- Keeps overall grid use and self-sufficiency consistent with standard behavior
If no export limit is set, this consumption schedule will behave in the same way as self-consumption.
How It Works
Instead of immediately charging the battery whenever there is surplus solar:
- The system may export up to the limit earlier in the day
- This creates spare capacity in the battery for later
- Later, when the there would have been curtailment if the battery was full, the battery can instead charge due to “saved space”
- Result: less or no curtailment, and more energy used or sold
This can increase value for systems with feed-in tariffs or where curtailment otherwise reduces economic return.
Enabling Grid Export Limits
- Open a design in Design Mode
- Go to System settings for that design
- Locate Grid export limit under the Advanced section of the System settings menu
- Enter the maximum export value required by the utility → Leaving this blank means no export limit is applied.
- Click “Simulate system” to re-simulate with the new export limit applied
Viewing Curtailment in Charts
When an export limit is set:
- Solar production above the limit appears as a curtailed band in the energy chart
- Hover over the chart to see curtailed kWh values
- Annual summaries include total curtailed energy
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Choosing Self-consumption (min curtailment) Mode
When an export limit is set, you can toggle the Self-Consumption Mode to optimize battery operation:
- On the storage settings page, set the Consumption schedule to be Self-consumption (min curtailment)
- Re-run your simulation
What Doesn’t Change
- Battery logic remains the same in existing consumption schedules
- Export limits do not affect grid import behavior
- Arbitrage strategies not tied to self-consumption remain unaffected
Tips
- Use this feature in markets where export limits are mandated (U.K., parts of Europe)
- Compare results with and without self-consumption (min curtailment) mode to evaluate economic impact
- Check annual and monthly views for curtailment insights