Here in the Minnesota, electricity consumption usually peaks at
the height of summer when most air conditioners are in operation.
Due to capacity shortfalls and equipment malfunctions in the power
grid, the utility company occasionally has problems meeting the
electricity demand; power outages and "brownouts" (when the
delivered voltage falls well below 110 volts) are the result. In
fact, we just encountered the first blackout of the season last
night: our residential neighbourhood lost power for about 4 hours,
beginning at around 10:15 p.m.
In order to help "stabilize" the demand, the utility company offers
a 10% rebate on your residential electricity bill if you agree to
install a cutoff switch on your a/c unit. This switch is operated
by the utility company, and they use it to switch off your a/c unit
during periods of peak demand to help reduce the strain on the
power grid. There is no charge to have the switch installed, and by
law, the utility company can not deactivate the a/c unit for more
than 10 minutes per hour.
