Reuters: Spanish electricity demand rose 2.8 percent year-on-year in 2007 to 260,838 gigawatt hours (GWh), grid operator Red Electrica (REE.MC: Quote, Profile, Research) said on Thursday. Stripping out the effect of different working days and temperature changes, demand rose 4 percent. Demand reached its peak on the evening of Dec. 17 when it hit 45,450 MW as Spaniards turned up the heating during a very cold snap. That was 4 percent higher than the previous minute-by-minute record of …