(a) A public utility may self-insure all or part of the utility’s potential liability or catastrophic property loss, including windstorm, fire, and explosion losses, that could not have been reasonably anticipated and included under operating and maintenance expenses.
(b) The commission shall approve a self-insurance plan under this section if the commission finds that:
(1) the coverage is in the public interest;
(2) the plan, considering all costs, is a lower cost alternative to purchasing commercial insurance; and
(3) ratepayers will receive the benefits of the savings.

(c) In computing a utility’s reasonable and necessary expenses under this subchapter, the commission, to the extent the commission finds is in the public interest, shall allow as a necessary expense money credited to a reserve account for self-insurance. The commission shall determine reasonableness under this subsection:
(1) from information provided at the time the self-insurance plan and reserve account are established; and
(2) on the filing of a rate case by a utility that has a reserve account.
(d) After a reserve account for self-insurance is established, the commission shall:
(1) determine whether the account has a surplus or shortage under Subsection (e); and
(2) subtract any surplus from or add any shortage to the utility’s rate base.
(e) A surplus in the reserve account exists if the charges against the account are less than the money credited to the account. A shortage in the reserve account exists if the charges against the account are greater than the money credited to the account.
(f) The commission shall adopt rules governing self-insurance under this section.