Every smart lighting article promises you’ll save money. Almost none of them show you the arithmetic.
So here it is — the real numbers, including the part that works against you, and the one factor that changes your savings by more than double depending on which household you happen to be.
If you already run LED bulbs, the honest answer might surprise you.
First: your tariff tier changes everything
This is the single most important thing in this article, and I’ve never seen a smart home guide mention it.
TNB charges domestic users on a progressive block tariff. You don’t pay one flat rate — you pay more per unit as your monthly usage climbs:
| Monthly usage | Energy charge |
|---|---|
| First 200 kWh | 21.80 sen/kWh |
| 201–300 kWh | 33.40 sen/kWh |
| 301–600 kWh | 51.60 sen/kWh |
| 601–900 kWh | 54.60 sen/kWh |
| 901 kWh and above | 57.10 sen/kWh |
On top of every tier sits an ICPT surcharge — currently around 3.70 sen/kWh, reviewed periodically — plus the KWTBB levy and a minimum monthly charge.
Check these against your own latest TNB bill before you trust them. Tariffs get revised, and your bill is the authority, not this article.
Here’s why the tiers matter so much. When you cut electricity usage, you’re not saving at the average rate — you’re saving at your highest tier rate, because the units you remove come off the top of your bill.
Cut 40 kWh a month from a household already using 950 kWh, and you save roughly 40 × 60.8 sen ≈ RM24.
Cut the same 40 kWh from a household using 180 kWh, and you save roughly 40 × 25.5 sen ≈ RM10.
Same behaviour, same bulbs, 2.4 times the saving — purely because of where you sit on the tariff ladder.
So before you buy anything, look at your bill and find your monthly kWh. If you’re under 200 kWh, smart lighting will not pay for itself on electricity and you should buy it for convenience instead. If you’re over 600, the numbers start working properly.
The part nobody mentions: smart bulbs use power when they’re off
A smart bulb is never truly off. It keeps its WiFi radio alive so it can hear you switch it on, which draws somewhere in the region of 0.3 to 0.5 watts continuously.
That sounds trivial. Across a house, it adds up:
Ten smart bulbs at 0.4W, running 24 hours a day, 30 days a month:
0.4W × 10 × 24 × 30 = 2.88 kWh per month
At the top tier that’s about RM1.75 a month, or RM21 a year, that you’re paying purely for the privilege of the bulbs being reachable. At the bottom tier it’s closer to RM0.73 a month.
This is not a reason to avoid smart bulbs. It is a reason to be sceptical of any article claiming pure savings without mentioning it — and a reason not to put smart bulbs in rooms you light twice a month, where the standby draw genuinely can exceed what you save.
If you want to know your own figure exactly, a cheap plug-in energy meter will tell you in an afternoon.
Where the savings actually come from
There are three sources, and they’re wildly unequal in size.
1. Replacing incandescent or halogen bulbs — large
If you still have old filament or halogen bulbs anywhere, this dwarfs everything else in this article.
A 60W incandescent running 5 hours a day:
60W × 5h = 300Wh/day = 9 kWh/month
A 9W LED doing the same job at the same brightness:
9W × 5h = 45Wh/day = 1.35 kWh/month
Saving: 7.65 kWh per bulb per month.
Across five bulbs, that’s 38 kWh a month — between RM10 and RM23 depending on your tier.
But notice what’s doing the work here. That saving comes from LED, not from smart. A dumb LED bulb costing a fraction of the price saves you exactly the same amount. Anyone selling you a smart bulb on these figures is taking credit for something LED technology did.
2. Automation preventing waste — moderate, and the real smart-specific saving
This is the only saving that genuinely belongs to smart lighting, and it depends entirely on how wasteful you currently are.
Say three bulbs in your house routinely get left on for four hours a day when nobody’s in the room — the porch light burning until noon, the bedroom light on all afternoon, the hallway on all night.
3 bulbs × 9W × 4h = 108Wh/day = 3.24 kWh/month
Now subtract the standby draw of the whole system. With eight smart bulbs at 0.4W:
8 × 0.4W × 24h × 30 = 2.88 kWh/month
Net saving: 0.36 kWh/month. At the top tier, about 22 sen.
Read that again, because it’s the honest finding this article exists to deliver: if you already run LED bulbs and you’re moderately careful about switching them off, smart bulbs will save you approximately nothing. The standby draw eats the automation gain.
The maths only turns positive when the waste is genuinely large — an outdoor light left on all night, a whole floor lit in an empty house, someone in the household who never switches anything off. If that’s your home, automation wins comfortably. If it isn’t, be honest with yourself.
3. Dimming — small but real
Running a bulb at 50% brightness genuinely uses roughly half the power. LED dimming is close to linear, unlike old incandescent dimmers which mostly wasted the difference as heat.
Living room lights at 60% in the evening instead of 100% is a saving you’ll never notice visually and never notice on the bill either — call it one or two ringgit a month. Worth setting up because it’s free and takes thirty seconds, not worth buying anything for.
A worked example
Let’s take a real household. Four-bedroom terrace, three people, 650 kWh a month — so the marginal tier is 54.60 sen plus 3.70 ICPT, call it 58.3 sen/kWh.
They install eight smart bulbs. Five replace 60W halogens that ran 5 hours a day. The remaining three replace LEDs.
Savings:
- Halogen → LED on five bulbs: 5 × 7.65 = 38.25 kWh/month
- Automation cutting genuine waste (porch light overnight, roughly 3h/day at 9W): 0.81 kWh/month
- Evening dimming across three bulbs: roughly 0.5 kWh/month
Costs:
- Standby on eight bulbs: 2.30 kWh/month
Net: 37.26 kWh/month saved.
At 58.3 sen/kWh: about RM21.70 a month, or RM260 a year.
Against a spend of, say, RM320 for eight decent bulbs, that’s payback in roughly 15 months — and then genuine profit.
Now run the same household without the halogens — everything already LED:
Net: 0.81 + 0.5 − 2.30 = −0.99 kWh/month. They lose about 58 sen a month.
Same house. Same bulbs. Same automations. The entire difference is what was there before.
Five automations worth setting up, ranked by what they actually save
1. Outdoor and porch lights on a sunset/sunrise schedule. The biggest single win in most homes, because outdoor lights are the ones most often left burning into daylight. Use sunset/sunrise triggers rather than fixed clock times so it self-adjusts through the year.
2. “Everyone’s out” — all lights off. Ties lighting to your phones leaving the house. Catches the expensive mistake of lighting an empty home all day.
3. Motion-triggered hallway and stair lights at low brightness. Set them to 15–20% between midnight and 6am. Saves against the alternative of someone switching on a full-brightness light and leaving it on, and it’s far pleasanter at 3am.
4. A hard “lights out” time. Everything off at, say, 1am regardless. A blunt instrument that catches every case you forgot to plan for.
5. Evening dimming. Living areas to 60% after 8pm. Tiny saving, zero effort, and it makes the room nicer.
Three automations that sound clever and save nothing
Colour changing. No meaningful power difference between colours, and you’ll stop using it within a fortnight.
Sunrise wake-up fade. Genuinely lovely. Costs slightly more power than just switching the light on, since the bulb runs for twenty minutes instead of two. Buy it for the experience, not the bill.
Smart bulbs in rarely-used rooms. Store rooms, guest bedrooms, the back bathroom. You light them for a few minutes a week while paying standby 24/7. These are the rooms where smart bulbs genuinely cost you money. Put dumb LEDs there.
So should you buy them?
Work through this honestly:
Buy for savings if you still have incandescent or halogen bulbs, or your monthly usage is above 600 kWh, or there’s genuine waste in your home — lights burning in empty rooms, outdoor lights on all night. In these cases the payback is real and lands inside two years.
Buy for convenience if you’re already fully LED and reasonably disciplined. That’s a perfectly good reason to spend money. Waking to a light that fades up, telling the house to go dark from bed, coming home to a lit porch — these are genuinely nice, and nobody needs to pretend they’re an investment.
Don’t buy if you’re under 200 kWh a month, already on LEDs, and expecting the bulbs to pay for themselves. They won’t. You’d be spending a few hundred ringgit to save a few ringgit a year, and you’d be better off putting that money towards an IR blaster for your air-conditioner — where the numbers are far more favourable, because AC dwarfs lighting on almost every Malaysian bill.
The honest summary
Smart lighting is a convenience product that sometimes saves money, not a savings product that happens to be convenient.
The money is made by LED replacing halogen, and by automation cutting genuine waste — and if neither applies to your house, standby draw quietly cancels out most of what’s left.
That’s less exciting than what most articles tell you. It’s also what you’d want a friend to tell you before you spent RM300.
Run the numbers against your own bill — find your monthly kWh, identify your tier, and count how many non-LED bulbs you still have. That’s a ten-minute exercise that will tell you more than any review.
This post is part of my complete guide to building a smart home under RM2000 — start there if you’re planning a full setup.
Sources: TNB domestic tariff rates as published for 2026. Rates are revised periodically and the ICPT surcharge is reviewed every six months — always check your current bill for the rates that apply to you.