Batteries
Storage turns sunshine into power you can use after dark.
Why batteries matter for solar
Solar output peaks around midday, but demand often peaks in the evening. A battery stores surplus daytime energy and releases it later, so more of each day’s sunshine is actually used. For homes, a battery can also keep essential circuits running during a power cut.
Chemistries
Most new storage uses lithium-ion batteries. Among them, lithium iron phosphate (LFP) has become the leading choice for stationary storage because it contains no cobalt or nickel, tolerates many charge cycles and is less prone to overheating. Other technologies, such as flow batteries, are being developed for longer storage durations.
Advantages and limitations
Advantages
- Shifts solar into the evening peak
- Backup power during outages
- Helps grids absorb more solar
Limitations
- Adds significant cost to a system
- Capacity fades with use, heat and deep discharges
- Needs safe installation and end-of-life recycling
Current development
Battery prices have fallen sharply, and grid operators are adding storage alongside new solar farms. Longer-duration storage, lasting many hours or days, is the next frontier.
Further reading
- Battery energy storage system (Wikipedia)How grid batteries work
- Lithium iron phosphate battery (Wikipedia)The LFP chemistry explained