(EnergyAsia, May 9 2011, Monday) — Singapore’s electricity tariff could rise further after reaching a 30-month high of S$02.558 per kilowatt-hour (kwh) in the second quarter. (US$1=S$1.22).Singapore Power (SP) Services said it raised electricity tariff by an average of 6.5% from the first quarter on the back of strong oil prices this year, with Brent…