Home energy storage field situation

Are home storage systems the future of battery energy storage?

The global battery energy storage market has grown rapidly over the past ten years. Home storage systems have made an important contribution to this growth, representing one way for the public to participate in the energy transition.

Can a multi-year field measurement predict the battery capacity of home storage systems?

The multi-year field measurements provide insight into the operation of home storage systems. We subsequently developed a method for estimating the usable battery capacity of home storage systems tailored to their operational patterns.

Is there a capacity estimation method for battery energy storage?

Now, a large open-access dataset from eight years of field measurements of home storage systems is presented, enabling the development of a capacity estimation method. The global battery energy storage market has grown rapidly over the past ten years.

Why are home storage systems important?

Home storage systems have made an important contribution to this growth, representing one way for the public to participate in the energy transition. In Germany alone, 1.5 million home systems (see Battery Charts) are installed, with manufacturers giving warranty periods of around ten years.

Can a lithium-ion home storage system be measured in a field?

To validate this method, we performed a total of 60 field capacity tests over the lifetime of 18 systems (Fig. 1a,b). To the best of our knowledge, there are no comparable multi-year field measurements of lithium-ion home storage systems. Fig. 1: Field capacity tests and validation of the capacity estimation method.

How much capacity does a home storage system lose per year?

We find that the measured home storage systems lose about 2–3 percentage points of usable capacity per year on average. Most systems still reach their given warranty period, owing to the inclusion of an ageing reserve in the capacity (that is, more capacity is installed than stated in the datasheet).