Cal. Elec. Code § 19005

In the case of electrical failure or other emergency, the official conducting the election may direct that ballots may be marked by pencil or ink. In that event, the elections official may duplicate the voted ballot cards as provided in Section 15210 and count the duplicate ballots by automatic tabulating device, or may count the voted ballots pursuant to Article 5 (commencing with Section 15270) of Chapter 3 of Division 15.