Shifting load out of peak hours

Short answer. Load shifting only saves money if you are on a time-of-use tariff, where peak and off-peak units are priced differently. On an ordinary domestic bill the hour of use makes no difference at all — only the monthly total does.

Applies: All year · Cost to do: Costs nothing · Indicative saving: around 60 units a month

First, check whether it applies to you

Look at your bill. Two sets of readings and two energy lines means you are on time-of-use billing. A single reading pair and one energy line means you are not, regardless of what kind of meter is on the wall.

If you are not on TOU, shifting load changes nothing on your bill. This is worth establishing before rearranging a household routine around it.

Rank loads by energy and by flexibility

Water heating, laundry, dishwashing, ironing and water pumping score high on both — they use real energy and their timing is arbitrary. These are the candidates.

Refrigeration cannot move. Lighting is precisely what defines the peak. Cooling is the difficult case, because the peak window coincides with when people most want it.

For a household whose evening load is lighting, fans and a television, the shiftable share is small and TOU changes little. For one running a pump, a washing machine, an iron and an electric geyser, moving those four is a real saving.

Pre-cooling as partial shifting

Cooling cannot be moved but part of its energy can be brought forward. Running the air conditioner harder before the window opens and raising the setpoint during it shifts some consumption into the cheaper period.

How much this is worth depends entirely on the building. A concrete house with an uninsulated roof loses stored coolth quickly; a better-insulated one holds it long enough for the saving to be real.

Peak hours are not load shedding hours

The two frequently overlap because both track system demand, but they are different things. A feeder can be shed outside peak hours and can run uninterrupted through them.

Confusing them leads people to believe they are being charged a peak rate during an outage, which is impossible — no units are recorded when supply is off.

What to actually do

Check your bill for two reading sets before changing anything.
Read the peak window printed on your own bill at the start of each season rather than working from memory.
Move laundry, ironing and dishwashing to the middle of the day or late at night.
Set the water pump and the geyser timer to run outside the window.
Pre-cool before the window opens and raise the setpoint during it.
On rooftop solar, shift these same loads into daylight — that converts export at the credit rate into self-consumption at the retail rate.

Frequently asked questions

Does shifting load help if I am not on a TOU meter?

Not on the bill. A non-TOU meter records a single total priced on the ordinary schedule, so the hour makes no difference. It can still help the network at a system level, but it will not change what you pay.

Should I ask to be moved onto a TOU tariff?

Only after doing the arithmetic. Total your shiftable loads against your fixed evening loads — if more than half your consumption is stuck in the peak window, TOU will cost you more, not less.

Related guides

Cutting air conditioning cost without losing comfort — summer, costs nothing
Water heating: the largest saving in most Pakistani homes — winter, costs nothing

The numbers behind this

All 10 guides are ranked by value in the index. To see what your own house needs, run the efficiency audit.