When planning to install a solar energy storage system, do you wonder when the costs will be recouped and when it will start generating profit? Indeed, this is a concern for everyone considering the substantial initial financial and time investment. Today, using California, USA as an example, we will discuss how long it takes to recover the costs after installing a home energy storage system.

Is It Worth Installing Solar Systems?

We all know that the installation cost of home energy storage in California, USA, is not insignificant. A system with ‘8 kW photovoltaic + 10 kW storage battery’ can have an installation cost as high as $26,000. Given such a substantial investment, what is the return on investment like? Is it truly worth installing?

Firstly, let’s establish that residential energy storage is definitely worth the investment! You can expect to recoup your initial costs in approximately 7-9 years and save between 70,000 to 100,000 on electricity bills over the next 20 years. It’s a long-term investment with a very substantial return.

So, from which aspects can we expedite the payback of the installation costs for a solar power system? There are several influencing factors to consider:

Factors Influencing Returns

Installation Cost

The cost of solar installation in California varies by region, installation company, and system size, but typically ranges from 2 to 4 per watt.

Government Subsidies and Tax Incentives

Subsidies and tax policies from the U.S. government, along with state-level incentives like those in California, can reduce a significant portion of the overall costs.

(1) Federal Investment Tax Credit (ITC)

The ITC allows you to deduct 30% of the cost of your energy storage system off your federal taxes. In other words, your investment cost is effectively reduced by 30%, with the remaining amount covered by the federal government.

(2) California Self-Generation Incentive Program (SGIP)

SGIP offers a rebate of up to $200 per kWh based on the capacity of the battery you install, which could save you thousands of dollars on installation costs.

Electricity Cost Savings

After installing a solar power system, you will notice a significant reduction in your household electricity bills. The savings on electricity can be used to offset the initial investment. With California’s electricity prices being higher than the U.S. average, the energy-saving effect is even more pronounced.

Electricity Rates

Currently, California’s three major electric utility companies: Pacific Gas and Electric Company (PG&E), Southern California Edison (SCE), and San Diego Gas & Electric (SDG&E), all implement Time-of-Use (TOU) pricing. This means they charge different rates during peak and off-peak periods based on electricity usage. For example, PG&E divides the year into summer and winter periods, and further categorizes each day into three periods: “off-peak, mid-peak, and on-peak.

Summer Period June 1 to September 30
Winter Period October 1 to May 31
Off-Peak (Least Expensive) 3 PM to 4 PM, 9 PM to 12 AM
Peak (Most Expensive) 4 PM to 9 PM
Shoulder Period All other times

Under the Time-of-Use (TOU) pricing mechanism, the cost of electricity for the average consumer is likely to increase. This is because when your demand for electricity is high, it tends to coincide with high demand from others as well. At these times, you are required to pay the higher peak electricity rates.

However,  the TOU pricing mechanism can be beneficial for users who have installed residential energy storage systems. This is because, with a storage battery, we can store electricity when the rates are at their lowest. Then, we can use the stored electricity during peak demand times, thus reducing the need for grid electricity when it is most expensive.

Therefore, the larger the price difference between peak and off-peak rates, the more you can save on electricity costs!

System Size and Efficiency

Larger or more efficient systems can generate more electricity during sunny weather, which can accelerate cost recovery.

Net Metering Policy

California implements a net metering policy that allows solar system owners to sell excess electricity back to the grid for credits, which also helps to improve the return on investment.

Revenue Calculation

First, let’s assume the following system is installed:

8kW Photovoltaic Cost: $3.3/W
10kWh Battery Cost: $1,300/kWh
Federal Investment Tax Credit (ITC) 30%
SGIP Rebate $150/kWh
Electricity Demand Satisfaction 100%

If you are a customer of SDG&E

We will consider two scenarios: “Solar PV Only” and “Solar PV + Energy Storage System

In the case of installing “Solar PV + Battery”, the investment cost can be recovered in approximately 7 years, and about $102,780 in electricity expenses can be saved over the next 20 years, resulting in a net return on investment of $76,700. However, if only solar PV is installed, the return on investment would decrease to $32,800, and the payback period would extend to 9 years.


Based on the aforementioned factors, the payback period for solar systems in California typically ranges from 5 to 10 years. However, this figure can vary depending on specific circumstances. To obtain a more accurate estimate, one can use an online solar savings calculator, or contact a local solar provider for a detailed assessment.

Recommend Solar Battery

10kwh All In One Energy Storage System | DL-LFP-51200
10kwh Rack Mounted Lithium Battery | DL-LFP-BE51200
10kwh Stackable Lithium Battery | DL-LFP-HS51200
10kwh Wall Mounted Lithium Battery | DL-LFP-HW48200

10kwh Powerwall Battery | DL-LFP48200