TEXAS, CALIFORNIA POWER GRIDS PASS HEAT-WAVE TEST

So far this week, Texas and California have passed a major heat wave test that stressed their power systems with record demand.

Temperatures topped 110 F (43C) for much of this week in parts of several Western states including California, Arizona and Nevada.

Power grid operators in Texas and California urged consumers to conserve energy to reduce strain on the system.

Although both grids kept calls for conservation in effect Friday, temperatures, power demand and prices were all lower in both states compared with earlier in the week — though anything can happen if a major power plant or transmission line fails.

In Texas, the Electric Reliability Council of Texas (ERCOT), which operates the grid in most of the state, said demand peaked at a June record on Monday, but with hot weather expected all summer, that will likely be tested.