Observations on Residential and Commercial Load Shapes During a Cold Snap

Electricity consumption in the Pacific Northwest reaches a peak during days of extremely cold weather, due to the large amount of electric space heat in the region. The cold snap of February 1989 prompted the Bonneville Power Administration to examine hourly load shape data by end-use, comparing average winter days to peak winter days. It was observed that end-use load shapes can be very different on peak days, with implications for demand side management programs. The End-Use Load and Consumer Assessment Program (ELCAP) has collected hourly end-use electricity data for several hundred residences and commercial buildings in the Pacific Northwest. Analysis of ELCAP data indicates that most space heat load shapes have a higher load factor on a peak day than on an average winter day. Peak day load shapes are compared with average day load shapes for single-family residences and several commercial building types. In the residential sector, it was observed that electricity consumption increased for all end-uses, not just space heat, during the cold snap. Load shapes for newer homes, those built to Model Conservation Standards, did not exhibit the increase in space heat load factor found in older homes.