That’s according to a new study by researchers at the University of Warwick, the University of Birmingham and decarbonisation consultancy Cenex, who say this problem would cost homeowners £400 in the first year alone.
The organisations say degradation is characterised by a reduction in both the usable energy capacity and the power output of the battery.
As part of the study a 4kW solar system and a 2kWh battery were installed in a home in Loughborough.
Over five years, battery resistance almost doubled while a fifth of the initial battery capacity was lost.
The researchers said this caused a “tangible loss” in generation from the solar panels, reducing the revenue created from exporting extra energy.
The researchers said: “Without battery storage, the sum of utility savings and electricity export profits is £727, meaning the battery costs the home owner £1/ annum.
“When the cost of battery degradation is included, the annual loss to the home owner is significant and the economic viability of solar home systems with electricity storage using lithium ion batteries is totally diminished.”
It claims this could cost homeowners £400 in the first year and up to £1,000 over the lifetime of the system.