Key Takeaways

  • Export curtailment happens when a utility limits how much rooftop solar you can send to the grid; that reduces feed-in revenue but creates an opportunity to store energy and raise self-consumption.
  • A residential battery (5–15 kWh typical) can raise self-consumption from ~30% to 60–90% depending on size and usage; round-trip efficiency is commonly 85–95% according to current market figures.
  • Smart inverters with export control and time-of-use integration let you shift surplus to loads or batteries; expect installed battery costs roughly $400–$900 per kWh and payback in 3–12 years depending on rates and incentives.

What You Need to Know

Export curtailment is applied when local circuits or utility rules limit exported power (commonly 1–5 kW limits in constrained areas, according to current market figures). If your system produces more than the allowed export at midday, excess solar is curtailed (lost production) instead of being used or sold. That matters most where net metering or feed-in credits are low: retail electricity prices in many US regions run $0.18–$0.40/kWh while export credits may be $0.03–$0.15/kWh, so avoiding curtailment has direct dollar value.

Home batteries store that midday excess. Key specs to watch: usable capacity (kWh), continuous discharge power (kW), and round-trip efficiency (%). Typical consumer options: 5 kWh (compact), 10 kWh (common), 15+ kWh (high capacity). Inverter compatibility is crucial: PV inverter and battery inverter must support export-limiting, grid codes, and firmware updates.

Smart inverters can limit export in real time, direct surplus to batteries or controllable loads, and respond to time-of-use (TOU) signals. They can also reduce export to comply with utility limits, avoiding forced curtailment while maximizing onsite use.

How to Save Money

  1. Measure your baseline: Install or review generation and export logs for 2–4 weeks to find midday export kW and daily exported kWh. Use that number to size a battery: if you export 8 kWh/day and want to capture 80%, target ~8 kWh usable capacity.
  2. Choose the right battery: Compare cost per kWh ($400–$900/kWh installed according to current market figures), usable capacity, warranty (typically 5–10 years or 5,000–10,000 cycles), and continuous discharge power (3.3 kW to 10 kW common). A 10 kWh system at $6,000–$9,000 installed is a useful reference point.
  3. Pick a smart inverter solution: Ensure it offers export limiting, TOU scheduling, and remote updates. Smart inverters let you prioritize battery charging and direct power to loads (EV charger, water heater) during peak solar to increase self-consumption by 20–50 percentage points.
  4. Time rooftop upgrades strategically: If panels are older than 10–15 years or showing >10–15% degradation, upgrade when you also install battery/inverter equipment to avoid duplicate installation costs and to ensure inverter compatibility. Incentives and rebates sometimes have application windows—check local programs and act within 3–12 months if credits are expiring.
  5. Operational tips: Shift heavy loads (EV charging, pool pump, dryer) to midday PV generation. Use battery discharge during peak-price TOU periods to avoid paying $0.25–$0.40/kWh. Monitor performance monthly to tune battery charge thresholds and export limits.
  6. Prioritize sizing: Size battery to capture typical daily exported kWh rather than oversized to reduce upfront cost.
  7. Consider stacking benefits: Demand charge reduction for some customers can shorten payback to 3–5 years.
  8. Check warranties and expected cycles: Replacing a battery after 8–12 years should be factored into lifecycle ROI.

Bottom Line

Export curtailment reduces the value of rooftop solar but can be managed cost-effectively. Combining an appropriately sized battery (5–15 kWh range), a smart inverter with export control, and timed rooftop upgrades improves self-consumption from roughly 30% to 60–90% and preserves value that would otherwise be curtailed. Use short-term monitoring (2–4 weeks) to size systems to your actual exported kWh, compare installed cost per kWh ($400–$900/kWh range), and align upgrades with incentives and inverter compatibility to shorten payback, typically in the 3–12 year range depending on local rates and rebates.