Kenya Power disconnected electricity supply to Naivasha GK Prison, staff quarters and an annex facility over a Sh6 million unpaid bill on Friday.
The prison has more than 3,000 inmates, some serving death sentences, while the annex has those on jail terms of up to five years.
Security in and around the prison was heightened to keep inmates in check following the disconnection that officer in charge Patrick Mwenda described as unfair.
Mwenda confirmed that the facility owes Kenya Power but said the matter could have been resolved amicably as it poses "a major security risk for the whole country".
He added that the disconnection could result in a humanitarian crisis due to the resulting lack of water supply to the prisoners.
“All the work in the industrial section has stalled due to lack of electricity. Operations in the prison have come to a standstill,” he said.
He added: “The power bills for the prison and staff quarters are different. We are wondering why the power company is punishing our staff."
A senior Kenya Power officer, who declined to be named, said the electricity supply to the prison was cut off late last year over debts but that promises to clear them were made.
“The management failed to clear the whole amount leading to the move. The supply shall resume when the debt is cleared,” the officer said.
