Home Batteries Could Cut Rooftop Solar Exports By Up To 90%
What Happened
Adding home batteries to residential rooftop solar systems could reduce households’ daytime solar exports to the grid by 85-90%, according to a report by energy think tank Ember. The analysis models a 3-kW rooftop solar system paired with a 5-kWh battery. Such a setup could shift around 1,600-1,800 units of electricity annually from daytime exports to evening household consumption. However, the battery significantly changes the economics: the estimated payback period rises from 3.3 years for solar alone to around nine years with storage.
Key Takeaways
Home batteries could help households use much more of their own rooftop solar after sunset, but their higher upfront cost currently makes the investment considerably slower to recover. Ember estimates a 50% battery subsidy could reduce the payback period to around 6.3 years.