Jan 19 (Reuters) - Nearly all of Texas" electric generation units and transmission facilities have passed the state"s new winterization rules, the state grid reported just before the expected coldest day so far this winter hits the West Texas Permian oil and natural gas producing area on Thursday. Extreme cold in Texas, which caused power plants and gas pipes to freeze last February, was the reason state agencies adopted new power plant winterization and other rules to avoid a repeat of last winter"s energy emergency. read more The Electric Reliability Council of Texas (ERCOT), which operates most of the state"s power grid, on Tuesday filed its final winter weatherization readiness report, which showed 321 out of 324 facilities passed the new rules. “The Texas electric grid is more prepared for winter operations than ever before,” Interim ERCOT Chief Executive Brad Jones said in a release. Last year"s Winter Storm Uri killed more than 200 people, caused power and gas prices to spike to record highs in many parts of the country and left around 4.5 million Texas homes and businesses without power and heat - in many cases for days. read more High temperatures in Midland in West Texas will drop from 60 degrees Fahrenheit (15.6 degrees Celsius) on Wednesday to 36 on Thursday before rising to 50 on Friday, according to AccuWeather forecasts. That compares with a normal high of 61 F at this time of year. ERCOT said it conducted onsite inspections at 302 electric generation units during December, representing 85% of the megawatt hours lost during Uri due to outages, and 22 transmission facilities. The grid operator said three resources require further review but remain operational. ERCOT said the state Public Utility Commission will determine any potential enforcement actions resulting from the inspections. Last year, the Texas Legislature increased the maximum penalties for violating weatherization rules to $1,000,000 per day per violation.