If your bill shows peak units and off-peak units, you have a time-of-use (TOU) meter. Instead of one slab rate, TOU billing charges a higher rate during peak hours, when national demand is highest, and a lower rate during the rest of the day.
Who has TOU meters?
- Residential consumers with a sanctioned load of 5 kW or more.
- Most commercial and industrial connections.
- Some other categories as set by the tariff.
What are peak hours?
Peak hours are usually a four-hour window in the evening, and the timing shifts by season — earlier in winter and later in summer. DISCOs announce the current timings, and many bills print them. Because these windows can be revised, check your bill or DISCO notice rather than relying on a fixed timetable.
How the bill is calculated
- Peak units × peak rate
- Off-peak units × off-peak rate
- Plus fixed charges (if applicable), adjustments and taxes.
Since the peak rate is significantly higher than off-peak, the same number of total units can cost very different amounts depending on when they were used.
Reading a TOU meter
TOU meters cycle through several screens. Look for registers labelled for peak and off-peak (sometimes T1/T2 or with codes listed in the meter's guide). Note both numbers on the same day each month and compare with the bill.
How to save with a TOU meter
- Shift heavy loads — washing machines, water pumps, irons, electric water heaters — to off-peak hours.
- Pre-cool your home before peak hours start and raise the AC temperature during peak.
- Use timers on pumps and geysers.
- Solar users: daytime generation naturally offsets off-peak units; batteries can help cover evening peak hours.
For businesses
Factories and shops with TOU meters can see large savings by moving shifts or heavy processes outside peak hours. Larger connections are also charged based on maximum demand (MDI), so avoid starting all motors at once.
Common errors
- Peak and off-peak readings swapped.
- Meter clock set wrongly, so units are recorded in the wrong register.
If your peak units look too high compared with your usage pattern, ask the DISCO to check the meter's time setting.