Researchers at the University of Texas at Austin have found that storing solar energy for nighttime use increases a household’s annual energy consumption compared with using solar panels without storage. On the other hand, storage by utility companies significantly reduces the amount of electricity generation capacity required.
The researchers estimated that adding energy storage to a household with solar panels increases its annual energy consumption by about 324 to 591 kilowatt-hours – an increase of about 8 to 14%. The increase is primarily due to the increase in energy consumption required to account for storage inefficiencies because storage consumes some energy every time it charges and discharges.
On the other hand, storing energy at the utility was found to reduce peak grid demand by 8 to 32%. This, in turn, reduces the amount of electricity generation capacity required.