News
The carbon footprint of a light bulb: electricity and CO₂
A bulb gives off no smoke, but the electricity it uses is generated somewhere. How lighting connects to CO₂, how to calculate it and what a lamp’s full life cycle looks like.
Why incandescent bulbs waste most of their power as heat
An incandescent bulb makes light from a glowing metal filament, and that method has a physical limit. Where the energy goes, how halogen differs and how LEDs deal with heat.
A ceiling full of halogen spots: how consumption changes with LED
Dozens of halogen spots in a suspended ceiling can add up to several hundred watts. How to identify your spots, calculate the difference and avoid the traps when switching.
Switching a whole home to LED: which bulbs to replace first
Switching every light in the home to LED saves money and time when it is planned. The steps, from making a list to checking compatibility and disposing of old lamps.
Checking how much of your meter reading goes on lighting
Rather than guessing from the bill, use the meter reading and its pulse light to measure what your home lighting actually consumes.
Do hot bulbs make your air conditioner work harder in summer?
Every watt a lamp uses ends up as heat in the room. Here is how that affects cooling in summer and when the difference is actually noticeable.
Why a cheap LED bulb can turn out expensive
The cheapest LED bulb on the shelf looks like a bargain at the till. Here is how it can cost you later and what to check before you buy.
The energy label: how to read the A–G scale
The coloured label on a lamp box shows energy efficiency. We explain how the scale was rescaled and what the letters actually stand for.
How much electricity a multi-bulb chandelier uses
Eight, twelve, sometimes twenty bulbs in one chandelier. How to work out what they use together, and practical ways to bring that figure down.
Why LED lighting is the choice for solar power systems
In an off-grid solar system every watt means panel area and battery capacity. Here is why LED lighting decides how big the whole system has to be.
12 V battery-powered LED lighting for cabins and garages
Running LED lights from a car-type battery in a garden cabin or garage with no mains: choosing lamps, wiring, fusing and working out battery capacity.
Household lighting habits: simple rules for saving energy
Swapping bulbs is only half the saving; the rest depends on everyday habits. Simple rules that everyone in the household can actually follow.
Lamp life: how many years 15,000 hours lasts in daily use
What do the hours printed on the box mean in everyday life? A simple way to turn rated life into years, and the conditions behind that figure.
Lighting during power cuts: running LEDs on a UPS or generator
Keeping the lights on at home or in a small office during a power cut: choosing a UPS or generator, sizing the LED load and avoiding common mistakes.
Lighting circuits and switches: light only what you need
Putting every bulb on one switch is tiring and wasteful. Here is the logic of splitting light into zones and a few practical layouts.
Using the savings calculator: entering the right figures
A calculator is only as accurate as the figures you give it. Here is how to work out lamp count, old wattage, hours of use and tariff step by step.
Changing bulbs on high ceilings: why long life matters
On a ceiling you cannot reach with a stepladder, replacing a bulb means extra labour, time and risk. How to account for that hidden cost and reduce it.
Do smart bulbs use power when they are switched off?
A smart bulb switched off in the app is not truly off: its wireless module keeps listening. How to estimate that standby consumption.
How big a share of home electricity goes on lighting
Lighting's share of household consumption differs from home to home. Instead of trusting a ready-made percentage, here is how to work it out for yours.
Is the heat from incandescent bulbs “free heating” in winter?
An incandescent bulb turns most of its energy into heat. Is that heat really useful in winter, or is it an expensive, inefficient way to warm a room?
Does warm light use less energy than cool light?
Whether a bulb of a given wattage gives warm or cool light does not change its consumption. Where the myth comes from and what really matters when choosing.
What determines the price of an LED bulb
Two LED bulbs that look identical can differ several times in price. Here is what drives the price and where cheapness hides its costs.
Lighting a living room: a step-by-step plan
A living room is for guests, TV and reading alike. Instead of relying on a single chandelier, here is a step-by-step plan for building light in layers.
Bedroom lighting: comfort and practicality
Bedroom light has to work for dressing and tidying as well as winding down for sleep. How to place ambient and local lighting.