Some 10,000 Massachusetts residents and business customers will be offered green pricing in a pilot project starting January 1. Enova Energy, a sister company of San Diego Gas & Electric (SDG&E), is one of five power providers in the New England state that will offer customers the option to pay more to receive electricity from "green" energy sources. The initiative is aimed at helping SDG&E prepare for California's soon-to-be-deregulated electricity market. Environmental sensitivity is one of the three options to be offered, along with variable rates or added services. The announcement, a glimpse of how traditional utilities are gearing up for deregulation, comes just weeks after parent company Enova Corp of San Diego announced in October that it would merge with the parent of Southern California Gas Co, Pacific Enterprises. The merger will result in one of the country's largest publicly held utilities, serving six million customers. It is also part of a trend of twinning natural gas and electricity companies.