Reduce Your TNB Bill: 9 Ways to Cut Home Electricity Base Load

Electricity base load is a home’s continuous minimum power draw, running even when most appliances and electrical equipment are off. In a shared rental property, this underlying usage contributes to a single Tenaga Nasional Berhad (TNB) bill.

While “base load” also describes the minimum daily power demand of an entire utility grid, this article focuses strictly on residential usage. It breaks down what makes up a home’s base load, details the actual draw measured in a real example of a Selangor terrace house, and suggest practical steps homeowners can take to reduce their property’s electricity base load and TNB bill.

What electricity base load is

A watt measures electrical power at a single moment, while a kilowatt-hour (kWh) measures that power over time. Because TNB bills by the kWh, the wattage printed on an appliance label only translates to your bill when multiplied by its actual running hours.

Standby power is the energy a device still draws while plugged in but switched off or idle, the definition used by the Lawrence Berkeley National Laboratory. A television or phone charger left in the socket is standby. That trickle is part of the base load, because it continues while the device sits unused.

A refrigerator is part of the base load for a different reason. The compressor cycles on and off through the day while the appliance stays on the circuit and keeps the cabinet cold. The household leaves it running, so those cycles contribute to the base load along with the standby devices.

On the other hand, air conditioning is a switched load. The unit draws power while a room has it running, and that draw stops when someone switches it off. The aircond electricity cost guide covers that switched use. Similarly, a shower instant water heater uses electricity only when it is used. These high-power appliances therefore do not contribute to the base load.

In simple terms, the electricity base load is the power the house still consumes even when there is no one at home and all unused appliances are turned off.

Why the floor matters: a case study

To see how base load adds up, consider the following data from a two-storey, 1800 square feet terrace house in Selangor with a 5 person household. Monitored by Universiti Teknologi Malaysia researchers between 2016 and 2017, this study provides a practical case to examine.

Their kitchen refrigerator had a nameplate rating of 206 watts. Using TNB’s formula (watts × hours of operation × 30 days ÷ 1,000), running at a continuous maximum draw for 30 days would consume 148.32 kWh. However, because the compressor cycles, the actual measured usage was 118.8 kWh a month.

For comparison, a typical electric vehicle that can travel 400km on a single charge uses about 60 kWh. That means the base load from that refrigerator alone is equivalent to fully charging an electric vehicle twice!

The hot-and-cold water dispenser showed a similar story. It was rated at 630–770 watts for the heater and 90–110 watts for the cooler. The household left it plugged in 24/7, and the appliance drew an average of 52.5 kWh a month as its internal elements cycle on and off constantly.

Together, these two base load appliances consumed 171.3 kWh a month. For Peninsular domestic accounts under 1,500 kWh, myTNB breaks the tariff down into three parts: an energy charge (27.03 sen/kWh), capacity charge (4.55 sen/kWh), and network charge (12.85 sen/kWh), totaling 44.43 sen/kWh. Applying this combined rate, the fridge and dispenser cost RM76.11 monthly.

Since the studied house averaged 390.0 kWh total, it stayed comfortably in this band. The TNB tariff guide explains how these components combine for a full account.

That RM76.11 only covers energy, capacity, and network usage. TNB also applies a RM10 monthly retail charge, an Automatic Fuel Adjustment (AFA), an Energy Efficiency Incentive, and service tax (SST), all of which are calculated against the home’s total bill, not individual appliances.

Note: TNB normally waives the retail charge, AFA, and SST if a property’s total usage is at or below 600 kWh. However, from 1 September through 31 December 2026, myTNB temporarily raised this exemption threshold to 800 kWh. The threshold reverts to 600 kWh on 1 January 2027. Because component rates fluctuate, always verify the live schedule on myTNB.

Why Base Load is Often Overlooked

On paper, a 206-watt refrigerator seems insignificant next to a 3,600-watt instant shower heater or a 900-watt air conditioner. However, because the fridge never powers down, it quietly dominates consumption. In the Selangor study, the refrigerator was the single largest energy user, consuming 118.8 kWh or 30.5% of the home’s total electricity. By contrast, the two air conditioners (running for about four hours a night at a conservative 28°C) drew a combined 45.2 kWh a month, finishing well below the fridge.

This heavy base load usually goes unnoticed because a standard TNB bill does not itemize it. The bill only displays the property’s total kWh and the resulting aggregate charges. In shared rentals, tenants naturally focus their cost-cutting attention on the obvious, high-wattage air conditioners, while the constant hum of the base load hides within the grand total.

Because standard property meters only read the combined draw, separating these background costs requires extra effort. While resources like How smart metering works explain how to track a property’s overall usage, they won’t give you a separate base-load line. This is why the fair utility billing guide recommends splitting shared baseline items like the fridge and common-area lights evenly among roommates, while metering and billing bedroom air conditioning separately.

What stayed on in the measured house

In the Selangor case study, researchers isolated and metered several specific loads:

• Refrigerator: 118.8 kWh a month (active on the circuit 24/7).
• Water dispenser: 52.5 kWh a month (left on 24/7).
• Television (standby mode): 0.9 kWh a month.
• Standing fan (50-watt rating): 0.4 kWh a month. (Because the household turned it off when not in use, it barely registered; a fan only joins the base load if left running continuously).

The study grouped the remaining appliances – the router, modem, internet box, ceiling fans, and lighting – into an unsplit “others” category, which collectively consumed 130.0 kWh a month. Because the researchers did not individually meter items like standalone freezers, water pumps, or security cameras, this breakdown excludes specific kWh figures for those devices.

Standalone freezers operate identically to refrigerators, falling into the same “cold appliance” category. TNB notes that the Energy Commission star rating label provides a tested annual kWh to help shoppers compare refrigerators, freezers, and domestic fans in-store. However, those lab-tested estimates serve only as a baseline and will differ from the real-world 118.8 kWh actually drawn by an active, occupied household.

Practical ways to reduce base load

The steps below target the appliances most likely to be running around the clock in a Malaysian home. These are practical steps that can be taken immediately and does not require any rewiring or special tools.

Refrigerator

A fridge consumes less energy when it holds its internal temperature steadily, because the compressor runs for shorter cycles. According to TNB, three common faults force the compressor to overwork: a defective thermostat, low refrigerant, or a damaged door gasket. Practical steps:

• Check the door seal. Close the door on a piece of paper. If you can pull the paper out easily, the gasket no longer seals properly and warm air is leaking in.
• Leave space around the unit. Push the fridge flush against the wall and the condenser coils at the back cannot shed heat efficiently. TNB recommends leaving a gap so air can circulate.
• Set the thermostat to the middle range. Turning the temperature setting to its coldest forces the compressor to run longer than necessary to keep food preserved.
• Avoid a second fridge unless necessary. Adding another “cold appliance” doubles this portion of the base load. If the household only needs extra space during Hari Raya or Chinese New Year, a cooler box with a lot of ice is much cheaper.

Hot-and-cold water dispenser

The water dispenser in the Selangor study consumed 52.5 kWh a month because both the heating and cooling functions stayed on 24/7. Most floor-standing dispensers have separate switches on the back panel for the heater and the cooler. Practical steps:

• Turn off the hot-water switch. If the household only drinks room-temperature or cold water during the day, switching off the heater eliminates its heating cycles entirely. Flip it on 15 minutes before you need hot water.
• Add a plug timer. A mechanical or digital timer (available at most hardware shops for under RM20) can power the dispenser off overnight and switch it back on before the household wakes up.
• Unplug when away. If everyone in the house leaves for a weekend or holiday, unplug the dispenser completely. Unlike a fridge full of food, an empty dispenser bottle loses nothing while off.

WiFi router, modem, and set-top box

These devices individually draw little power, but they run 24 hours a day and most households never switch them off. A typical home router draws 6–12 watts, and an Astro or Unifi set-top box draws 15–30 watts even in standby. Over a month, a router plus a set-top box left on continuously can add 15–30 kWh. Practical steps:

• Plug the set-top box into a switched power strip. Rather than leaving it on standby, switch the strip off when the TV is not in use.
• Consolidate devices. If the household has a separate modem, router, and mesh node, a single combo unit (often provided by the ISP) reduces the number of always-on boxes.

Standby devices (TV, game consoles, chargers)

The Selangor study measured the television’s standby draw at only 0.9 kWh a month. Modern TVs and phone chargers draw very little on standby, so individual savings are small. However, a living room with a TV, soundbar, game console, and two chargers can still add up over 30 days. Practical steps:

• Use a single power strip with a switch. Plug the TV and its accessories into one strip and flip the switch off after the last person finishes watching. This cuts all standby draws at once.
• Unplug chargers when not charging. A phone charger left in the socket draws a small but unnecessary trickle. Making this a habit is the easiest base-load cut in the house.

Water pump

Multi-storey terrace houses and some apartments use a booster pump to push water to upper-floor bathrooms. These pumps cycle on whenever a tap opens, and some older models have a pressure tank that causes the pump to kick in briefly even when no tap is running. Practical steps:

• Check for leaking taps and toilet cisterns. A slow drip keeps the pump cycling, adding to both the water bill and the electricity base load.
• Listen for the pump running on its own. If you hear the pump start when no one is using water, the pressure switch or check valve may need servicing.

CCTV and security cameras

Home CCTV systems, doorbell cameras, and NVR/DVR recorders are designed to stay on. A typical IP camera draws 3–8 watts, and a small NVR can add another 10–20 watts. A house with four cameras plus a recorder left on 24/7 can add roughly 15–40 kWh a month. Practical steps:

• Turn off cameras you no longer need. Spare cameras covering empty rooms still draw power if left plugged in.
• Use motion-triggered recording where available. Continuous recording keeps both the camera and the recorder working harder than event-based recording.
• Avoid leaving a dedicated monitor on. If you only check footage on a phone app, switch off any always-on display connected to the NVR.

Indoor and outdoor lights left on

Corridor lights, porch lights, staircase lamps, and garden floodlights often join the base load by accident rather than by design. A single 10-watt LED left on for 24 hours uses 7.2 kWh a month; five such points add more than 35 kWh. Practical steps:

• Walk the property once after dark and once in the morning. Note any car porch, side corridor, or toilet lights that stay on when nobody is using them.
• Add a timer or dusk-to-dawn sensor for outdoor lights. A basic plug timer or photocell sensor switches porch and garden lights off during daylight and overnight quiet hours.
• Prefer motion sensors for corridors and staircases. Lights then run only when someone walks past, instead of burning through the whole night.
• Replace remaining always-on bulbs with the lowest-wattage LED that still feels safe. If a light must stay on for security, a 5-watt LED costs less to leave running than an older 20–40 watt bulb.

Vent fans and air filters

Bathroom exhaust fans, kitchen hood fans left running after cooking, and portable air purifiers or HEPA filters can run continuously for hours or days. A 30–50 watt fan left on continuously uses about 22–36 kWh a month. Practical steps:

• Switch bathroom and kitchen fans off after the room clears. Ten to twenty minutes after a shower or cooking session is usually enough; leaving them overnight is common but unnecessary.
• Put portable air purifiers on a timer or auto mode. Many units have a timer or air-quality sensor so they idle when the room is already clean, instead of running at full speed 24/7.
• Clean or replace filters on schedule. A clogged filter makes the fan motor work harder for the same airflow, raising the continuous draw.
• Do not leave a vent fan on “for cooling” all day. A standing or ceiling fan switched off when the room is empty does not contribute to the base load; one left spinning in an unused room does.

Choosing efficient replacements

When comparing new appliances, the Energy Commission’s star rating label (one to five stars) provides a laboratory-tested annual kWh figure for point-of-purchase comparison. A five-star fridge tested at 300 kWh a year will draw less than a one-star model tested at 500 kWh a year. However, real-world usage will differ from the label, as the Selangor study showed. TNB does not publish direct Ringgit estimates for upgrading, but the kWh gap between star ratings gives a reasonable basis for calculating savings at the current 44.43 sen/kWh combined rate.

Frequently asked questions

Base load is the silent hole in your wallet

In the Selangor case study, just the refrigerator and the water dispenser consumed a combined 171.3 kWh a month. Based on current Peninsular rates for accounts using 1,500 kWh or less, those two always-on appliances cost RM76.11 before factoring in the rest of the home’s consumption, standard retail charges, or taxes.

PowerLah automatically analyzes electricity base load for properties on its platform, eliminating the guesswork of shared utility splitting. Learn more about how PowerLah works.