Home Battery Payback Period Calculator

The basic formula

"Is a home battery worth it?" It is the question we hear most often. The honest answer: that depends on your situation. But with the right calculation, you can predict it fairly accurately. In this article, we show you how to calculate the payback period, with concrete scenarios and current 2026 prices.

Sounds simple, but the annual savings consist of several components:

• Avoided feed-in — electricity you store instead of feeding back at a low rate
• Dynamic tariff advantage — charge cheaply, discharge at a high rate
• Avoided feed-in costs — some suppliers charge fees for feeding back to the grid
• VAT refund — one-off 21% of the purchase price

Scenario 1: Average household with solar panels

Assumptions: 12 solar panels, 4,200 kWh generation per year. 3,800 kWh annual consumption. 60% of generation is currently fed back (2,520 kWh). Energy purchase price: €0.28 per kWh. Feed-in tariff after 2027: €0.07 per kWh. Home battery: 10 kWh, purchase price €4,500.

Savings calculation per year

Payback period calculation

With an expected lifespan of 15-20 years, you continue to earn €463+ per year for 7-12 years after the payback period. That is a total return of €3,200-5,500 over the lifespan. Payback period: 7.7 years.

Scenario 2: Small household, plug & play battery

Assumptions: 8 solar panels, 2,800 kWh generation per year. 2,500 kWh annual consumption. Home battery: 5 kWh plug & play, purchase price €1,800.

Calculation

Plug & play batteries often have a shorter payback period due to the lower purchase price and the absence of installation costs.

Scenario 3: Large household with heat pump

Assumptions: 20 solar panels, 7,000 kWh generation per year. 8,000 kWh annual consumption (including heat pump). Home battery: 15 kWh hardwired, purchase price €7,000 + €500 installation.

Calculation

With a large system, the absolute savings are higher, but the payback period is slightly longer due to the larger investment. However, the total return over the lifespan is considerably greater.

Factors that shorten the payback period

1. Dynamic energy contract

With a dynamic contract, you can actively trade on electricity prices. Charge at €0.05/kWh, discharge when the price is €0.35/kWh. This can yield €100-400 extra per year, depending on your battery capacity and how actively you trade.

2. Rising energy prices

The calculations above are based on current prices. If energy prices rise by 3% per year, your savings increase each year and the payback period shortens by 1-2 years.

3. Feed-in costs

An increasing number of energy suppliers charge feed-in costs. This makes a home battery extra profitable because you avoid those costs.

4. VAT refund

The one-off 21% VAT refund reduces your net investment directly. This is a significant advantage — on a battery of €5,000, that saves €1,050.

5. Subsidies

In some municipalities and provinces, subsidies are available for home batteries. Always check the current schemes with your municipality and on the RVO website.

Factors that lengthen the payback period

• Low own consumption — If you use little electricity, you won't fill the battery daily
• Few solar panels — Less surplus means less to store
• Fixed energy contract — No advantage from dynamic tariffs
• Expensive system with high installation costs — The investment is larger
• North-facing roof — Less solar generation

Comparison: payback period by battery type

The sweet spot for most households: a 10 kWh system with a payback period of 6-8 years.

Frequently asked questions

Is a home battery profitable in 2026?

Yes, for most households with solar panels, a home battery is profitable with a payback period of 6-10 years. Especially after the net metering scheme ends in 2027, the financial advantage grows. Assume a net return of 8-12% per year on your investment.

How do I calculate my own payback period?

Take your annual solar surplus (kWh that you feed back), multiply this by the difference between your energy price and the feed-in tariff, add any dynamic tariff advantage, and divide the net purchase price (after VAT refund) by this annual savings.

What is the payback period without solar panels?

Without solar panels, the payback period is longer: 10-15 years. You only earn on the difference between cheap and expensive hours with a dynamic energy contract. This yields €150-350 per year, depending on your strategy and battery capacity.

Does the increase in my property value count?

A home battery can increase the value of your property, similar to solar panels. However, this is not included in the standard payback period calculation. It is an additional benefit.

What about battery degradation?

Home batteries gradually lose capacity, similar to a phone battery but much more slowly. After 10 years, a good LFP battery still has 80-90% of its original capacity. This effect is small and already accounted for in the manufacturer's warranty terms.