Expanding Solar Panels with a Home Battery: Maximum Self-Consumption

More panels or a battery: which gives better returns?

Your solar panels produce electricity during the day, but you use most of that electricity in the evening. The result: a large portion of your generated energy goes to the grid, at a low feed-in tariff. The question then becomes: do you expand your installation with more panels, or add a battery?

In most cases, a battery is smarter than extra panels. More panels increase your production, but don't solve the timing problem. A battery stores the surplus you've already produced for use when you need it.

When extra solar panels are the wise choice

Extra solar panels are worthwhile if your production is significantly lower than your consumption. If you produce less than 60% of your annual consumption, expanding the installation is recommended before adding a battery.

• Self-consumption < 60%: you're feeding too much back, a battery helps immediately
• Peak production during the day: surplus that isn't used is waste
• Net metering scheme ending: every kWh fed back becomes less valuable
• Energy bill in the evening: still drawing expensive grid power despite having panels

Which battery suits your existing installation?

The choice of battery depends on compatibility with your existing inverter. There are three coupling principles: AC coupling (plug-and-play, works with any installation), DC coupling (more efficient, requires replacement or upgrade of inverter) and an all-in-one hybrid system.

A DC-coupled battery is more efficient because the electricity is only converted once. However, it requires a hybrid inverter. If your existing inverter is due for replacement or if you're starting a new installation, DC coupling is the recommendation.

Checking compatibility

An AC-coupled system such as the Anker Solarbank works with any existing installation. Convenient and straightforward, but slightly less efficient because the electricity is converted twice. For existing installations, this is often the most practical choice.

Check your inverter

Check whether your current inverter has a DC battery input. If so, you can often add a battery without replacing the inverter. If not, there are two options: an AC-coupled plug-and-play battery, or replacing the inverter with a hybrid version.

Choose the right coupling type

Most modern hybrid inverters (Huawei SUN2000, SolarEdge, GoodWe) support direct connection of high-voltage batteries. Check the battery manufacturer's compatibility list or ask our specialists for advice.

Step-by-step plan for expansion

Step 1: measure your self-consumption percentage. Step 2: calculate the storage potential (daily surplus). Step 3: choose a battery capacity equal to 60-80% of your daily surplus. Step 4: check inverter compatibility. Step 5: install and optimise via the app.

• You produce less than 60% of your annual consumption
• Your roof has space for extra panels with good orientation
• Your inverter has overcapacity (more input than panels deliver)
• You want to be more self-sufficient in winter as well

Conclusion

Adding a home battery to an existing solar panel installation is in most cases the best way to get more value from your current investment. You solve the timing problem without increasing the total panel area.

Request a personal consultation. Our specialists analyse your existing installation and recommend the system with the best payback period for your situation.