Is it a good idea to get a battery with my solar panels?

In 2025, the answer is often: yes – especially if you use a lot of electricity and have the option for flexible sales or grid balancing. A battery makes it possible to use more of your own electricity, sell the surplus strategically, and ensure a better return. Let's look at why.

🔋 What does a battery do in practice?

A battery stores the electricity from your solar panels that you don't use immediately. This gives you: Higher self-consumption (you buy less from the grid) Opportunity to sell electricity when it's worth more Access to payment for grid balancing (e.g., via True Energy or aggregators) Better economy and more flexible management of your electricity

💡 Example: Home with DKK 20,000 in annual electricity consumption

We take a typical household with the following profile as a starting point: Annual electricity consumption: DKK 20,000 Electricity price: approx. DKK 2.5/kWh Annual consumption: 8,000 kWh Solar panel system: 10 kW with 10 kWh battery System incl. battery: DKK 110,000 (conservative estimate) Expected lifespan: 20–25 years

📊 Three scenarios for economy and payback

The figures are based on conservative estimates and can be improved with lower hardware prices, higher electricity prices, or subsidies.

⚖️ What's the point?

Many believe that the battery is an expense that extends the payback period. It's the other way around: Without a battery: You sell electricity cheaply (typically 60–80 øre/kWh) With a battery: You use the electricity yourself (and save DKK 2.5/kWh) With grid balancing: You sell electricity when it's worth DKK 2–3/kWh I.e., you optimize both consumption and sales – and it's noticeable in the economy

🧠 Future energy management

The battery will be key to: Charging the electric car as cheaply as possible Avoiding peak loads Participating in the flexibility market (and getting paid for it) Dynamically managing the home's electricity economy – without doing anything actively

✅ Conclusion

A battery is not just an “extra expense”. It is a tool to lower your expenses and increase your income. If you: Have a consumption of DKK 15,000–25,000/year Can install an 8–10 kW system Are interested in flexible sales and grid balancing ... then the battery is an economic and strategic gain, not a cost.