What the federal rebate actually doesThe rebate is designed to knock thousands of dollars off the upfront cost of a home battery system. Sustainability : Use more of your own clean solar energy, cutting emissions. Account for warranties – make sure your system is covered for at least the payback period. For many households, a 10 kWh battery installed under the federal rebate comes in at a six to 10-year payback period. That 10kWh battery average payback period is a general estimate based on a few key assumptions rather than a precise calculation for every household.