Not us, but a friend of DH's is thinking of doing this. Can't work out if he's genius or foolish?
He doesn't have a smart meter, and says that the power company have never read the meter (had been there about 4 years, meter is inside, he's never arranged for them to read it). He just inputs meter readings every so often. Quarterly?
His genius/foolish plan - send in false higher meter readings than he has actually used now. So say he's used 50 units, he sends in a reading for 90 units. Save again next month. By the next price increase in October, he's paid for 80 units he hasn't actually yet used, at current rate. Then he uses the power to catch up with his readings as the unit price goes up in Oct..