According to The Telegraph, the unnamed power plant was out of operation for four days before staff were finally able to fix the problems.
The newspaper also reports that water infrastructure in 12 US states was attacked at the same time, but it is unclear whether there is any direct connection.
This is about an incident that affected a small-scale energy facility, a government spokesman confirmed to the PA news agency.
At no stage was there any risk to the energy system in general.
Intelligence services in several Western countries have often warned that hackers from Russia, Iran and other hostile states could disrupt essential societal functions.
