US spot power and natural gas prices in Texas and California fell to negative territory on Tuesday due to mild weather reducing demand. This is a sign that energy firms are producing too much power or gas, leading some firms to cut back on output or pay others to take their gas or gas. In West Texas, average cash gas prices at the Waha Hub remained in negative territory for a record 47 straight days due to pipeline constraints in the Permian region, the nation's largest oil-producing shale basin. Analysts have long suspected that negative prices are a sign of a need for more gas pipes. Power prices in some Electric Reliability ​Council of Texas regions were also negative for several hours.