Residential electricity rates for Atlantic City Electric customers will go up again in June by more than 17%, the New Jersey Board of Public Utilities said Wednesday.That’s an extra $28.02 per month, the BPU said, citing high demand and a shortage of supply in a press call announcing the results of the annual basic generation service auction.The Press of Atlantic City also reports Atlantic City Electric customers are already reeling from overall rate increases of about 20% last year, causing many to question whether the company was making billing errors.