TURNING SOLAR AROUND
Why More Solar Panels Should Be Facing West, Not South
Matthew L. Wald, December 1, 2014 (NY Times)
“…A new study of 110,000 California houses with rooftop solar systems confirmed that a vast majority of the panels were pointed south because most of the panel owners were paid by the number of kilowatt-hours the panels produced…Electricity prices are higher at [the late afternoon] period of peak demand…Houses with solar systems consume less than half as much utilitydelivered electricity as ordinary houses, the study found. But from about 4 p.m. through the night, they consume more, and they add to the system’s peak demand, which comes around 5 p.m…
“Pointing panels to the west means that in the hour beginning at 5 p.m., they produce 55 percent of their peak output. So a 10-kilowatt system would make 5.5 kilowatts. But point them to the south to maximize total output, and when the electric grid needs it most, they are producing only 15 percent of peak, or 1.5 kilowatts…While some solar panel owners are paid timeofuse rates and are compensated by the utility in proportion to prices on the wholesale electric grid, many panel owners cannot take advantage of the higher value of electricity at peak hours because they are paid a flat rate…So the payment system creates an incentive for the homeowner to do the wrong thing…”