Electric rates will rise by about 20 percent this summer, but because of quirks in the rate structure and decreases in natural gas prices, SDG&E is predicting that most customers will see little no increase on their overall utility bills. Set to begin May 1, the summertime electric rate hikes will primarily apply to small businesses, though some residential customers will also see increases, according to San Diego Gas & Electric. The electricity increases were mandated by the California Public Utilities Commission to encourage conservation in the summer when the state's generating capacity is hardest pressed. But the utilities...