AUSTIN, Texas-- The Texas electric grid managers are appealing to the public again to shut off their lights or any other nonessential consumers of electricity.

The Electric Reliability Council of Texas is making the appeal each afternoon this week as record afternoon heat breeds record demand for electricity.

ERCOT initiated what it calls Energy Emergency Level 1 at 2:50 p.m. Wednesday after reserve generating capacity for the grid fell below 2,300 megawatts. An ERCOT statement says reserve margins over demand peaks are "expected to be very tight" this afternoon "and ERCOT operators are closely monitoring the situation.

Level 2 occurs of the reserve margin falls below 2,000 megawatts and involves cutting power to large commercial and industrial users. Level 3 involving rotating power outages comes if the margin falls below 1,750 megawatts.